Open architecture imaging apparatus and coil system for magnetic resonance imaging

The present invention relates to magnetic resonance imaging (MRI), and more particularly to open structure patient support systems with built-in and separable radio frequency coils, and positioning methods used in MRI.

Magnetic resonance imaging (MRI) detects a weak nuclear magnetic resonance (NMR) signal emitted from a hydrogen atom after being excited by a radio frequency signal in the presence of a strong magnetic field. This NMR signal is detected using a coil called an antenna. The term "coil" is also commonly used to mean an antenna and its housing or support structure. As described above, "coil" is also used in the sense of a structure including a plurality of coils. "Coil element" is used to mean an electronic component of a device, wireless coil, or antenna.

The NMR signal is extremely weak. The sensitivity of the coil to this signal decreases rapidly as the distance between the coil and the object increases. Therefore, for example, the coil or butterfly coil, solenoid coil, volume coil, or coil surface of FIG. 8 is placed so as to be in close contact with the area to be imaged. The unnecessary image area adds unnecessary noise to the resulting signal, so the coil size is small and can easily fit the patient on the MRI table to obtain only the image of the subject of interest. It has become like. Coil localized in the tissue of interest tends to have a higher signal-to-noise ratio (SNR) than larger coils, such as "body coils" for large patient scans.

As the size of the local coil decreases, its field of view or sensitivity profile decreases. When an image of a larger area is to be obtained by using a smaller coil, it is necessary to use a large number of small coils in combination at the same time or move the coil with respect to the image acquisition area.

The coils can be operated individually as a large number of coils phase-arranged in circular deflection or quadrature. The combination of signals from multiple coils can improve the yield of SNR. Part of the challenge associated with using multiple coils for imaging is the fact that the fields of individual coils interact as coil-to-coil couplings, which are the quality factor Q values of the coils. Works in the direction of reducing. Prior art has presented various patents aimed at reducing this coupling. One technique that seeks to reduce intercoil coupling in a multicoil array is to superimpose adjacent coils by approximately 10%, helping the additional fields cancel each other out and eliminating the coupling. .. In some cases where there are more than two coils, the superposition decoupling process is complex, coil coupling occurs even between coils that are not in the closest relationship, and field cancellation is significantly more complex. In these cases, the coupling can be reduced by adding a capacitor or inductor or additional circuitry between the coils causing some coupling. A low impedance preamplifier can be added to the coil system to reduce the coil coupling effect. In most prior arts, combinations of these various techniques have been described and successfully adopted.

Also, while the body coil and other coils are operating in transmit or excitation mode, the coil must be blocked or disconnected from the magnet body coil in order to operate the coil as a receive-only coil. There is. Again, various prior art patents seek to improve this process.

<p num="0007"> Another consideration for coil systems concerns the ability to operate in parallel imaging mode. In these modes of operation, imaging techniques such as SMASH, SENSE, PILS, or GRAPPA require the coil to have an image-independent volume. Based on the sensitivity profiles of these independently operating coils, a reconstruction algorithm is executed to allow the entire image volume to be reconstructed in less time than conventional image acquisition time. The coils acquire an image of independent volume for optimal parallel imaging, so decoupling strategies that employ coil overlap are not optimal.</p><p num="0008"> An additional consideration for coil technology and common MRI systems is to push towards a larger number of simultaneous imaging channels. Coil systems are typically implemented in 8-channel systems with eight separate antennas, but some systems currently implement up to 96 channels, and plans use more channels. The advantage of adding channels is to increase the acceleration factor in performing parallel imaging and to make the coil smaller to increase the signal-to-noise ratio. By driving this upgraded MRI constantly, the old coil system becomes obsolete. There is currently no way to upgrade the number of channels associated with the coil other than purchasing the entire coil device with the main structure and coil circuits and connections to the MRI.</p><p num="0009"> The coil must be wound to a Larmor frequency related to the magnetic field strength you are trying to operate, i.e. for 1.5T the coil must be wound to 63.86MHz, In the case of 3.0T, it needs to be wound to 127.7MHz. In most commercial coils, the coil element or antenna is inseparable from the patient support structure or from the coil housing. For each MRI with different magnetic field strength, therefore, a new coil system consisting of coil elements, coil housings, patient support structures and cables is needed.</p><p num="0010"> Most MRI images are related to signals from hydrogen atoms, but other nuclei (eg C)₁₃, K, P, Na) may also be the subject of MR spectroscopy or MR imaging at times. Traditionally, the low signal-to-noise ratios associated with the measurement of these nuclei have made it impossible to use in actual clinical therapeutic images. However, with the advent of advanced coil technology and stronger magnetic fields, these technologies have become more practical. However, in order to obtain these signals in the limited bandwidth of a standard MRI system, the coil must be coiled to the appropriate nuclear precession frequency (Larmor frequency), as well as the associated circuitry. .. There are several systems suitable for double-turn images (ie, combinations of hydrogen atoms with other atoms), but there are limitations regarding the integration of these multiple coils into the coil housing.</p><p num="0011"> Also, coil switching, multiplexing, or dynamic coil selection strategies activate and deactivate coil sets from large coil array sets. This strategy can be used to optimize coil subsets for images of smaller biostructures and to switch between target areas during image acquisition and image processing. To accommodate this strategy, the coil set or subset of these coils needs to be properly designed. Currently, no system incorporates this type of imaging strategy into the coil module system design.</p><p num="0012"> Another study of images, especially for a person's chest, is to change the imaging position when the chest is imaged by MRI, US (ultrasound) or mammography and surgical practice is performed. Surgery and ultrasound (US) imaging are performed almost exclusively in the supine position, whereas MRI often images the chest in the prone position, so physical buildup between these positions It is difficult to correlate the characteristics of. MRI images of the chest in the supine position are very difficult and there have been no successful trials.</p><p num="0013"> The complexity of coil technology and the demand for clinical treatment are increasing, and new strategies for coil systems are needed. The system is suitable for the size of the coil, the number of coils used can be maximized, and the strength of different magnetic fields, as well as the upgraded path provided to accommodate many image channels. It is required that the coil is wound corresponding to the atom and can be optimized for the parallel imaging structure.</p>

<p num="0014"> The present invention relates to medical imaging, particularly in the field of MRI radiocoil placement, and to support devices used to image the corresponding human tissue. The basis of the present invention is to disconnect the coil element (antenna) from the patient support system, which allows the radio frequency (RF) coil element to be attached and / or selected for image acquisition. You can do it. This concept applies to traditional "desktop" coils (ie, coils placed on top of a typical MR image tabletop), and also a special tabletop with integrated coil elements. It is applied to the dedicated stretcher that has. Means for optimizing the use of said coils have been presented by allowing positioning, support, immobilization and compression of the biological structure of the subject. In addition, various RF antennas and circuit configurations suitable for imaging in these image structures have been presented.</p><p num="0015"> The prior art is 1) a specific fixed coil arrangement for a dedicated purpose (head coil, heart coil, chest coil) or 2) a general coil arrangement to image the entire biological structure. , A separable coil arrangement, or 3) an arrangement where all the coils needed to image the entire body do not need to use a subset as an all-in-one system, or 4) imaging various biological structures. The focus was on one of the coil sets, which was assembled to. None of the prior art has focused on structures associated with a single living tissue and has provided no special use for structures associated with a single living tissue. That is, they do not have coil sets that meet the different imaging requirements for biostructure, i.e., for multiple chest coil sets (high SNR, for parallel imaging and practice, or for smaller patient sizes. Things and features (for spectroscopic applications) and features are not made as the various aspects of making a coil (electronic equipment, physical support of coil housings for electronic equipment).</p><p num="0016"> A desired component of the technique of the present invention is the ability to provide a patient support structure in combination with a coil. In the use of stable, sturdy supports, the coils can be removed and replaced without disturbing the patient (eg, when using coils with different magnetic field arrangements, as in repairs).</p><p num="0017"> The advantages of a coil system separable from the housing or patient support structure are 1) to construct a combined visual field (FOV) optimized for the patient's biostructure, and 2) to utilize all available receive channels. , Focusing them so as to image only the desired field of view, 3) Allowing the rearrangement, replacement and removal of coil elements without moving the patient, forming an opening for image-guided practice Points to be taken, 4) Use coil elements for larger or smaller magnetic field strengths and different nuclei, 5) Supply separable transmit and receive coil elements with different shapes, 6) Continuous images Alternatively, to facilitate and support the surgical procedure, provide a coil or compression arrangement optimized for positioning the tissue (eg, chest) in various arrangements, 7) separate the support structure for each configuration. Capable of making different coil configurations available to doctors without need, 8) upgrading coil elements to new or improved features without having to replace the entire assembly. That is.</p><p num="0018"> An important aspect of the invention is that the separable and reconfigurable coil system provides, for example, bilateral imaging (in the chest), unilateral imaging, chest wall imaging in patients with mammary resection or partial mammectomy, intervention. It is to enable coil configurations optimized for specific imaging purposes, such as procedures, strong field imaging, or multiatomic imaging. Another aspect of the present invention is a technique of combining a coil signal with an MRI scanner for data acquisition. Yet another embodiment is a particular coil shape optimized for bilateral and unilateral images in both receive-only and transmit / receive image applications (transmission and reception). In addition, these coil systems are designed for use in parallel imaging applications in transmit, receive and transmit / receive modes, such as SENSE and SMASH. In addition, the coil system can be operated in transmit SENSE or T-SENSE mode, where the coil array is used in conjunction with parallel imaging applications.</p><p num="0019"> Coil elements are unique to reduce coil-to-coil coupling, to place a large number of coils closer to the image object, and to maximize object coverage within the framework of a modular coil system. Can be placed.</p>

<figref num="1">(a) shows a patient lying prone on a chest coil tabletop on a standard patient transport stretcher. The stretcher is placed in front of an MRI system with a closed hole. (b) shows a patient lying prone on a dedicated chest image table top on a dedicated stretcher. The stretcher is placed in front of an MRI system with a closed hole. (c) shows a special stretcher with a table top that is distant from the MRI. (d) shows a table top attached to a magnet and automatically connected to a cable. (e) shows a table top with a vertically provided cable connection point. (f) shows this vertical table top attached to an MRI. (g) indicates a stretcher having a cable connection point. (h) shows a stretcher attached to an MRI with a cable connection that is automatically connected when docked.</figref><figref num="2">(a) shows a secondary support structure and a patient support structure for chest imaging without compression plates or coils. The illustrated cables are attached to various connection panels and ports on the support structure leading to the MRI connector. (b) shows a patient support structure with a sternum support attached. (c) shows the patient support structure with the support structure on the opposite side of the chest. (d) shows the patient support structure with the bilateral chest support structure attached.</figref><figref num="3">FIG. 3 is a front view of a patient support structure with various compression plates and secondary substructure attachments along with a patient in an appropriate position. (a) Show the anterior and lateral plates attached to the main structure with the patient in the proper position. (b) Indicates the front plate and the lateral plate arranged in appropriate positions. (c) Shows the front and side plates introduced as a secondary structure swiveled from the attachment of the main unit. (d) The front coil plate and the lateral coil plate introduced into the main support structure. (e) Front and side coil plates placed in place.</figref><figref num="4">(a) Shows a single loop coil with associated circuitry. (b) A single loop coil array equipped with a multiplexing device. (c) Two loop coils with electrical connectors that allow the coil to be disconnected from the cable. (d) Shows a small loop coil. (e) Shows a large loop coil. (f) Shows a butterfly coil with two loops and three loops. (g) Indicates a transmission line coil. (h) A loop-shaped transmission line coil is shown.</figref><figref num="5">(a) Shows a loop coil housed in a coil housing with coaxial wires for connection. (b) Shows a loop coil housed in a coil housing with electrical / mechanical connectors. (c) Shows a loop coil with a wireless / optical conversion circuit and a mechanical / optical connection. (d) A side view of the chest support structure with the patient on top is shown. (e) Shows a coil plate attached to a compression frame with a cable connection to an MRI. (f) Shows a coil plate attached to a compression plate with electrical / mechanical connections to the compression plate. (g) Indicates a coil plate attached to a compression plate with a wireless connection to the compression plate. (h) A side view of the compression frame slider (middle) and the rail (top) supporting the coil (bottom) as an additional wireless implementation is shown.</figref><figref num="6">Various arrangements of coils integrated into one arrangement are shown. (a) 4 loop coils (b) 4 loop coils with alternating magnetic field detection are shown. (c) 4 small loop coils (d) 4 loop coils installed in the horizontal direction are shown. (e) Four butterfly coils (f) The combination of two loop coils and two butterfly coils is shown. (g) Shows four loop coils superimposed on four butterfly coils. (h) Shows four loop / butterfly coils installed horizontally. (i) Four transmission line coils are shown. (j) Two transmission line coils shown as a hybrid loop are shown. (k) Shows four superposed transmission line coils and four loop coils. (l) The four sets of transmission line line coil, loop coil and butterfly coil are shown.</figref><figref num="7">Axial views of patients with breasts placed in different arrangements are shown. (a) Shows a unilateral chest with various coil plate arrangements. (b) Shows a bilateral configuration with four independent medical / side plates. (c) Shows a bilateral structure with a posterior medical plate structure. (d) Shows a unilateral chest with an attached coil array. (e) The bilateral configuration of (d) is shown. (f) Shows a bilateral structure without compression.</figref><figref num="8">Various coil arrangements for bilateral applications are shown. (a) A bilateral coil plate with a loop coil in the lateral direction and a butterfly coil inside. (b) Shows a loop lateral coil and a butterfly intermediate coil with a central coil on a fixed intermediate structure. (c) Shows a loop lateral coil and a butterfly intermediate coil with a central coil on a fixed intermediate structure and two lateral coils attached to be anchored to the intermediate structure. (d) Shows the same configuration as (a) with two overlapping and separated lateral coils. (e) Shows the same configuration as (b) with two overlapping and separated lateral coils. Here, the middle butterfly coil has an asymmetric loop, which makes it easier to separate from the lateral coil when it is in a rearward position. (f) Shows the same configuration as (c) with two lateral coils housed in an open coil housing and two lateral coils that overlap and separate from each other. (g) Shows the same configuration as (d) with three overlapping and separated lateral coils. (h) Shows the same configuration as (E) with three overlapping and separated lateral coils. (i) Shows the same configuration as (f) with a lateral coil housed in an open coil housing and two laterally overlapping and separated lateral coils. Here, a front connection is provided between the lateral coil and the intermediate coil. (j) Shows the same configuration as (g) with two overlapping and separated lateral coils and two overlapping and separated intermediate coils. (k) Shows the same configuration as (h) with eight overlapping and separated lateral coils and eight overlapping and separated intermediate coils. (l) Shows the same configuration as (i) with a lateral coil housed in an open coil housing and two overlapping and separated intermediate coils. Here, the connection is made from the front position.</figref><figref num="9">Multiple views of the chest compressed from above / below or above / below are shown. (a) Shows the chest compressed by a compression plate from anterior to posterior. (b) Shows the coil inserted in the compression plate. (c) Shows compression from the front to the two chests. (d) The arrow direction view of the front compression plate is shown. (e) Shows a diagonal swivel compression plate that compresses the chest from the front. (f) The arrow direction diagram of (e) is shown.</figref><figref num="10">Various compression arrangements for an open structure chest imaging system are shown. (a) Show a patient lying on an isometric immobilization plate. (b) Show the same patient lying prone on the same immobilized plate. (c) (b) is shown as seen from the plane in the direction of the arrow. (d) The axial view of the chest after inserting the position confirmation wire into the tumor site is shown. (e) Show the same patient after removing the immobilizer. (f) Shows the chest compressed from the front.</figref><figref num="11">(a) Dedicated body imaging used with a dedicated stretcher Shows a patient lying on his back on a table top. (b) Shows a rear support plate with various coil insertion portions. (c) Shows a rear support plate with a large FOV coil insertion. (d) The method of arranging the coil set in various positions inside the support plate so as to be the optimum position with respect to the body structure of the object is shown.</figref><figref num="12">(a) Dedicated prostate imaging on a dedicated stretcher Shows a patient lying on his back on a table top. (b) The axial view of the patient is shown. (c) Shown is a front support plate with a coil insertion section. (d) Shown is a prostate cover with a coil insert. (e) Shows a rear support plate with a coil insertion section.</figref>

By taking into account the following detailed description of the invention, those skilled in the art will appreciate the aforementioned features, objectives and advantages of the invention.

The techniques described below cover improved MRI methods with support structures and devices associated with improved coil systems. Preferred examples are described by reference to the general and specific properties and characteristics of the components of this technique. However, although this specification discloses only some specific examples as an example of the technique of the present invention, this does not limit the scope of the present invention. It will be readily apparent that numerous modifications and changes can be made without departing from the novel spirit and scope of the invention.

This technical disclosure includes RF coil design, mechanical system design, and methods of configuring coils to maximize signals from the system and enable imaging of body structures in previously unprovided forms. Is done. As an exemplary example, we describe chest imaging.

A basic aspect of this technical disclosure is the separation of the patient support structure from the RF coil system. This is embodied in a dedicated stretcher with a dedicated tabletop system for use in MRI (1) (Fig. 1 (b)) or a traditional tabletop system (Fig. 1 (A)).

As shown in Figure 1 (a), in preparation for MRI chest imaging, patient (4) is prone with the foot into the MRI hole (2) (as well as head to tip). Lying on. Prior art has shown a series of tabletop coil system designs for chest imaging, where the RF system is integrated into the mechanical structure of the device and is inseparable. Generally, the tabletop coil system (5) is placed on a stretcher for MRI and a general purpose tabletop, and in the case of chest imaging, the patient lies prone on this structure. In the case of a type of cylindrical magnet manufactured by General Electric, a patient transport stretcher is used to attach to the magnet. The stretcher (7) is generally a stretcher with wheels that can be mechanically attached (docked) to the magnet (1). A general purpose table top is used to insert the patient into the magnetic hole (2) and moves relative to the stretcher. This table top moves in and out of the magnet by various mechanisms. In the case of a cylindrical magnet manufactured by Siemens, a cantilever-type patient support that can be separated from the magnet is used. For Philips and Toshiba cylindrical magnets, removable patient supports have been introduced into different types of transport stretchers. The implementations provided by these magnet manufacturers are not designed for professional imaging or clinical use or special patient positioning, so they consist of a simple flat tabletop. A dedicated coil system mounted on a special purpose tabletop mounted on a transport stretcher is used to tailor the imaging capabilities of MRI to a particular body structure. An example of such an arrangement is shown in FIG. 1 (a).

The electronics housed in these coil systems are electrically connected to the MRI RF acquisition system. Various methods have been proposed for attachment to MRI systems. The most common methods at the time of filing this patent are 1) direct wire connection from the coil system to the mobile attachment of the MRI (General Electric) 2) wire connection from the coil system to the fixed part of the MRI (Phillips) 3). There is a wire connection (Siemens) between the coil system and MRI through the connection provided on the patient support. Both of these measures require the user to connect the coil system to the MRI by manually connecting the plugs. Additional means can include means that allow the wire to be directly connected to the MRI without the operator having to attach it. The process of attaching the tabletop coil system to the patient indicator and the process of docking the patient support and stretcher with the magnet make an electrical connection directly to the MRI system. The electrical connection of the coils is made by docking or mounting a stretcher or tabletop coil to the device. This allows the coil plug to be located very close, though not in perfect contact with the MRI connector. The user then has to make the connection, but the connector is located near the MRI connection port, which has the advantage of reducing installation complexity. This becomes more important as the number of connections (channels) required with MRI increases.

Various methods of connecting the RF cable (83) from the table top (8) to the MRI (1) are shown in FIGS. 1 (c), (d), (e), (f), (g), (h). It is shown in. The table top houses a cable set that connects to the MRI. These cables are connected to the MRI by mechanically and / or electrically connecting the tabletop to the MRI by moving the mobile station (3). Electrical connectivity ensures connectivity between the coils in the tabletop and the MRI RF collection system. Mechanical connectivity ensures that the table top moves in and out of the magnet without damaging the electrical components.

For magnets that provide more than 16 data acquisition channels, a means of facilitating the RF cable connection of the RF coil to the magnet is highly desirable. One such means is a special tabletop (rather than a general anatomical imaging function) that is attached to the magnet by an RF connection provided vertically or horizontally using the associated mechanical alignment. It has a table top design with specialized functions). In a preferred embodiment, the RF cable from the coil in the tabletop terminates in the horizontal plane of the tabletop at the end close to the MRI. In another embodiment, the RF cable is terminated by directing it to an upward or downward vertical plane. Figure 1 (c) clearly shows that the table top and stretcher are not docked. Figure 1 (d) clearly shows that the table enters the magnet, the table top (8) is connected to the mobile station (3), and the mobile station supports the connection point (80) to the MRI RF system. ing. Figure 1 (e) clearly shows how the table top with vertical connection is separated from the magnet. Figure 1 (f) clearly shows how the table top was lowered to the position of the mobile station, or the mobile station was raised to the position of the table top and the table top was attached. Figure 1 (g) shows a selective arrangement in which the RF cable is routed from the table top through the stretcher and from the stretcher (80) through the connecting pins on the stretcher to the magnet (80). Has been done. In this selective arrangement, the electrical connection to the MRI RF collection system on the table top is made by the action of docking the stretcher with a magnet.

The connection of RF electronics from the table top to the magnet, either through the mobile station (3) or through the connection from the stretcher to the MRI, is i) mechanical alignment and stretcher during the magnet docking operation. Includes connection from to a magnet, ii) connection to a mobile station (3) with a moving table top, or connection to a table top with a moving mobile station. The connection of the tabletop to the mobile station establishes an electrical connection by first providing a means of mechanically aligning between the two fitted connections, such as by pin and hole, taper alignment, etc. Before it is mechanically aligned. This is an essential feature of automatic connection to MRI. In one embodiment, these connectors are coaxial connectors and the center pin is shielded by the outer connector. In another embodiment, the signal is transmitted by an inductively coupled connection. In a third embodiment, the signal is transmitted by optical fiber. The requirement for mechanical alignment means is that it is applicable to all connection methods.

Automatic connection from the table to the MRI by a mobile station (3) or stretcher through these electrical connections (80) is a new concept with the benefit of reducing interaction with the user, many (ie 36). It provides a means to support electrical connections (above the channel). Overcoming the force of inserting electrical connectors is important when utilizing 36 channels or more. In the present invention, mechanisms such as levers, cams and motor driven linear or rotary actuators provide the mechanical forces required to facilitate connection to magnets. Another aspect of the invention includes the addition of a cover to protect the connector from dirt, liquids or patient / user contact. This cover is automatically lifted to protect the connector when the two sides are close to each other. (For horizontal alignment, the cover is lifted to cover the top of the connector, and for vertical alignment, the cover is lifted to cover the sides of the connector.) This cover protects the associated circuits from static electricity. It protects mechanically as well as it does.

Additional coil connection means can include attachments to wireless devices that transmit to the MRI. All inventions presented in this patent document are applicable to all types of means for attaching an RF coil system to an MRI system. In addition, an automatic coil tuning circuit system may be provided on the table top. This circuit must be located between the coil on the tabletop and the connection to the MRI. At present, there is no stretcher system that integrates an automatic coil tuning system, and is therefore a new invention.

In the prior art, the tabletop system does not provide a module support structure, a body structure immobilization system, a medical access port, a device guide means, or an additional RF structure attachment means. These systems are generally designed for generalized anatomy and are inflexible for positioning and imaging according to different clinical requirements and different body sizes.

A dedicated stretcher and tabletop system for chest imaging is shown in the prior art document (Piron et al, US Patent Application Publication No. 2005/0080333). The system offers a unique patient support table top specifically designed for chest imaging and practice. This system is shown in Fig. 1 (b). Stretchers have a large access volume beneath the chest to facilitate access to the chest for physician preparation and clinical application. According to this prior art document (Piron et al, US Patent Application Publication No. 2005/0080333), the coil is not integrated in the patient support and is removable. This concept can be extended to take advantage of the open structure of the system and the separation of patient immobilization and RF coil system functions.

Through the use of additional support structures, patient-specific placements and locations can be accommodated in a tabletop or coil system based on a dedicated stretcher. Figure 1 (b) shows improved access to the target anatomy by a system based on a dedicated stretcher. By providing a removable section of the structure, the biostructure, in this case the chest, is accessible in more directions. Additional support structures can be used to optimize the location of the patient's body structure.

As an example, Figure 2 shows a patient support structure and RF system for imaging a prone patient. The main support structure (8) is similar to both dedicated and stand-alone tabletop systems. In the figure, there are two options, one is to install the coil on the general-purpose table top, and the other is to replace the general-purpose stretcher and table top with a dedicated table top and a dedicated stretcher that integrate or house the coil elements. It is shown. In the figure, both the version with additional table tops and the system based on the dedicated stretcher are shown in the same way, but the length of the structure of the additional table tops is different from that of the dedicated table tops. The dedicated stretcher / table top has a longer support for the patient's overall length. The patient support structure (whether a dedicated table top or a stand-alone table top) includes 1) a structural support that allows the patient to take a comfortable position, 2) an electrical cable (11), and 3) an MRI system. Connector and circuit to enable connection / communication of, 4) Connection for secondary structural support, 5) Opening to provide access space and facilitate connection with substructure, 6) It provides (electrical and mechanical) connection points for mounting compression systems and immobilization devices, 7) electrical connections to compression and immobilization devices. The coil element can be integrated into the body of the structure, as is currently practiced, or may be detachably attached to the main support structure by the method according to the invention. According to the present invention, the separable coil has electrical and / or mechanical connections as well as mechanical connections to the main support structure. Signal transmission between the MRI and the coil is done through a cable through the MRI connector (12). With the advent of wireless technology, signals can also be transmitted by similar wireless means.

Secondary support structures (15, 16, 17) can be attached to the primary support structure (8) for optimal alignment of the patient's tissue for imaging or clinical purposes. These structures are essential to hold an important part of the patient's weight and to support the patient in a particular position. These structural elements are shown in Figures 2 (b), (c) and (d). FIG. 2 (b) shows the sternum support (15) attached to the support structure. This is a preferred configuration for bilateral images of the chest. This sternum support can accommodate the RF coil and can be electrically attached (14) to the cable (11) of the system. FIG. 2 (c) shows a unilateral chest support (16) for placing the non-imaged side chest in an off-position position. In FIG. 2 (d), a bilateral chest support (17) is inserted into the support structure. This support is provided with two bulges to rest the chest and secures the chest without pressure. It is desirable to have supports of various sizes for different chest sizes. These supports vary in size according to the size of the chest diagnosis. In extreme cases, the support is a small cup or plate used for mastectomized patients or the chest of men. This configuration allows different coil combinations to be used for different chest sizes.

This support (17) houses an RF coil for chest imaging and an opening for access to the chest. It is necessary to provide an electric connector or the like for transmitting and receiving signals to MRI together with a sternum support portion in which coil elements are integrated. The secondary support structure may contain additional coils. In addition, the bilateral support (17) may accommodate a gradient magnetic field coil, a transmit coil, a receive coil, or a transmit and receive coil. The ability to accept modularized coil elements in a replaceable support structure is a unique aspect of the invention. In addition, these secondary support structures can be provided with special coils to facilitate special chest imaging, such as imaging the rear of the chest armpit. This embodiment has side members that can be mounted on a compression frame below or above the patient support.

For example, a separable sternum support can be used to hold the RF coil array, support weight, and keep the patient in a fixed position. This support is separable from the body of the system, while it can be fixed and positioned for imaging.

In another embodiment, the secondary plate can be attached from the outside (side or bottom of the chest). These can be attached in a fixed position with respect to the body structure. In yet another embodiment, the coil set can compress against the chest wall of the chest. In this configuration, the coil is preferably used to image the patient with the breast removed.

In addition, this separable arrangement provides a means of providing additional coils elsewhere in the structure. Considering the exemplary case of chest imaging, providing an additional coil array in addition to the coils provided near the chest to cover other areas of the body in connection with breast cancer imaging. Has merits. In current practice, coil sets that are not specific to breast cancer metastases, such as body coils, scan different areas of the body. In the present invention, additional coils may be provided near primary support structures such as the liver, lobes, lymph nodes (chest, body and groin not covered by the neck and chest coils), adrenal glands, brain and the like. it can. These coils can be attached to a particular patient's table or selected during scanning of a particular image sequence. In either case, no special coil arrangement was presented in the prior art. As an application, these coils can be selected for patients with known cancers, while for screening applications, near the chest when the known cancers are not in other areas. All available channels can also be used for the located coil.

Adjustable compression systems, anatomy support, positioning and fixation devices are separably integrated into the patient support structure (Figure 3). They also provide the basis for positioning and guiding imaging and medical equipment to the target site. These compression systems (18, 19) consist of a flat plate introduced into the system, or a human body or a member having a surface that matches the desired shape, as shown in FIG. 3 (a). To. These compression systems are movably and lockable on trucks and rail guides, or are held by mechanical arms or the like. Since it is desirable to have multiple degrees of freedom for plate adjustment, lockable joints such as gimbals with multiple degrees of freedom are used, or the secondary guide rails are primary (and have multiple independent axes). Above the secondary is provided on the tertiary) adjustment member. A combination of multiple mechanisms is used to provide linear and rotational adjustments. These positioning devices are locked in place using clamps, cams, screws, straps and other fixing means. It is also possible to provide and maintain a force to support, immobilize and compress the patient by combining mechanical, electrical, hydraulic or pneumatic actuators with the member. By using an open structure system, the patient can support the structure, whether it is an extension tabletop system as shown in Fig. 1 (A) or a system based on a dedicated stretcher as shown in Fig. 1 (b). While fixed and lying, the target site can be supported, fixed, compressed and rearranged in various directions. This was possible only in a limited number of ways in the prior art and could only be compressed in the left-right direction in the tabletop augmented chest imaging system. One of the prior art systems provides frontal access to the chest (Piron et al., Supra). ). FIG. 3 (b) shows a compression plate (19) approaching from the lateral direction and a compression plate (18) approaching from the front. Similarly, from a medical approach, this structure can be provided. This open structure allows the compression plate and coil to be detached and attached from various directions without disconnecting the patient from the device. Structures other than the compression plate can also be introduced into the volume (9), which are referred to as secondary infrastructure equipment. In FIG. 3 (c), here is a frontal structure plate (20) that hinges on the sagittal plane around the patient's chest and a lateral structure that also hinges the frontal plane around the patient's chest. The plate (21) is shown. These plates can be swiveled around the site of interest, slid, or completely removed and reattached upon request. These plates are fed and locked in place with respect to the main support structure using a variety of mechanical clamping or fixing means (22).

These structures are brought to the structure's open access volumes for the following purposes: 1) Prevent the body from rubbing into the MRI holes as the patient enters the imaging position, 2) Provide attachment positions and fixation means for other structures and imaging and medical devices. 3) Provides additional coil support structure and mounting position, 4) with a structure that can withstand the weight of the table top when entering the hole of the magnet (when used with a special purpose table top with a dedicated stretcher) To provide a surface, 5) to collect blood, and 6) for a combination of these purposes. These, using mechanical locking mechanisms, electrical signals, or other means of communication, to inform the device and the user if the plate is not in the proper position for imaging or entering the imaging position. It is preferable to be able to communicate the locked / unlocked state of the plate. This provides a means of preventing the patient from entering the magnet until all plates are in place.

The compression plates (18, 19) provide an additional base for mounting removable RF coil systems (23, 24), gradient magnetic field coils, etc. These foundations provide a mechanical connection to the compression system and a signal connection to the MRI system, connecting the coil element to a movable compression plate to connect the coil signal to the MRI. One of the advantages of the RF coil system, which is separable from the main support structure and secondary structure as well as the compression / fixation system, is that the patient stays in the same position while the various RF coils are installed and removed. It is possible to do it. This is a unique and basic concept.

Decoupling the positioning and immobilization of the body structure from the supply of coil elements and other devices allows modular installation of the device while the patient remains in an immutable position. In addition, the RF coil system can be attached directly to the compression frame. These compression frames are then mechanically and electrically coupled to the main support structure by a single locking / fixing means. If the signal path is completed by fixed or locking means, it is not necessary to attach a movable coil to the MRI using separable cables or other signal coupling means. This is achieved by providing (eg) sliding electrical contacts along the adjustment range of the compression plate fixing means. This connection can be made in stable contact or can be closed by fixing the coil in place with a suitable fixing means such as a clamp, cam, lock or the like.

The use of modular gradient magnetic field generation electronics is unique and applicable to all organs (in addition to the chest), body areas, and limbs, as described. Since the gradient magnetic field coils are a major part of the MRI system, it is unique to integrate them into the patient-supporting bed. Connecting these gradient magnetic field coils to the MRI and signal generation cables and attaching the coils to the patient support structure or compression plate in a modular manner is a technologically novel aspect. .. Also, attaching the coil to the support structure and then attaching it to the MRI system by wireless technology (eg RF or optical communication) is new. Also, the ability of the RF circuit or imaging coil loop to complete when the compression plate is locked so that the coil is active in the locked position and inactive in the unlocked position is new and at the time of imaging. It has the advantage of ensuring that the plate does not move.

Also, the method of attaching the coil to the compression plate can be made to automatically select the appropriate signal channel through the connector and terminate the unused channel. The plug, here the termination plug, performs electrical termination to the end of the signal transduction cable set. In addition to properly mechanically provided keyed coil plates, suitable plug configurations for various electrical components such as electrical short circuits, open circuits, various loads (resistors, inductors, impedances from capacitors), etc. By using it, channel determination and routing to MRI can be performed automatically without the need for a multiplexing circuit. To achieve this, each coil plate must be coupled to the cable system by an N-terminal plug, where N is the maximum number of coils that can be included in each coil plate. For plates with less than N coils, a subset of these plugs connect to the coils and the remaining plugs connect to the termination circuit within the coil plate. N lines from each coil plate are combined with the number of input channels in the MRI system. With proper connector configuration, each unused terminated connection line in the coil plate is routed parallel to the active coil on a different connector, automatically providing a full set of active MR channel connections. .. The unused part of the cable system is terminated when the coil is plugged in. The fact that coils and coil arrays are attached to termination plugs is new. Further, a coil plate having a connector whose connection polarity is reversed when physically connected in the opposite direction has been proposed. The coil plate may also have a connector plug that couples to the receptacle at various angles (eg 0 degrees, 90 degrees, 180 degrees, intermediate angles, etc.). Here, the angle of coupling determines which cable system (and therefore MRI) channels and coil plates are connected (and which cables are terminated).

The compression / immobilization system may be constructed of a material that produces minimal artifacts when imaged using other imaging means such as ultrasound, X-rays, PET, CT, etc. preferable. This is achieved by matching the appropriate materials such that the excitation or detection of the signal is minimized by the presence of the compression / immobilization system (ie, acoustic transmission window, optical transmission window, optical semi). Transparent materials, X-ray transparent materials, non-magnetic materials, etc.).<u style="single">Radio frequency antenna</u>

Antennas or RF coils (also simply referred to as coils) used with the device have transmit and receive coils of various designs. A typical RF coil design for a simple receive-only loop coil is shown in Figure 4 (a). This RF antenna (33) consists of basic RF components including a multi-segmented RF coil conductor (25) with a distributed capacitor (26). One of the contacts is a passive blocking circuit (27) with an additional active blocking circuit (28) activated by a bias signal from the MRI. Throughout this specification, reference to RF-related matters should be understood to include a variety of additional circuits and components. Preamplifiers and adjustment circuits (29, 32) are provided close to the coil preferred for optimum SNR or towards the MRI connector (12). The preamplifier can be installed in any of 1) MRI system, 2) support structure, and 3) coil. There are many advantages to having a preamplifier in the coil because it can be easily replaced, optimized for a particular application, and placed closer to the coil for a larger SNR. In addition, a suitable current choke that minimizes the current in the shield of the RF conductor is provided by installing a current shield choke or balun (30, 31) or similar component anywhere through a cable, coil or RF system. provide. These concepts are presented by the prior art, but are presented here as background art.

If one or more coils are provided in the system, there are numerous ways to select them. Figure 4 (b) shows three coils, each separated with an appropriate overlap to eliminate mutual inductance. A multiplexer (34) can be used to select one coil. This is a common method of selecting a coil that exchanges transmission and reception signals with an MRI. This method is already known in the prior art. In FIG. 4 (c), two coils with an electrical connector (44) on the cable (11) are shown. When the coil is disconnected from the cable, the signal that was being exchanged with the MRI is no longer transmitted. In this way, various cables can be removed and replaced. In the preferred embodiment, a coaxial connector is employed, but a variety of connectors are available. Also, when disconnecting the coil from the cable, the circuit can continue to operate regardless of whether it is mechanically detached, electrically disconnected, or detached from any effect the cable has on the imaging system.

With reference to FIG. 4, a small loop antenna (35) or a large loop antenna (36) can provide a high signal-to-noise ratio and be sized appropriately for the clinical site. The butterfly coil (37) can be combined with the loop coil to form a quadrature phase configuration. This is disclosed in the prior art. However, the butterfly coil having multiple loops has not been widely used as a multi-coil shape. Microstrip transmission line coils (38) (Zang, US Patent Application Publication No. 2002/0079996) can be used in densely mounted configurations in a variety of shapes. These antennas can be combined with loops and / or butterfly coils in high density implementations, while with a nearly orthogonal field leading to high SNS and a unique magnetic field leading to high acceleration for parallel imaging. I will provide a. These microstrip coils can be remade into a loop coil or hybrid structure to form an appropriate imaging sensitivity profile (39). In addition, the opposed solenoid RF antennas provide good local imaging, in addition to the advantage of minimizing coupling with surrounding coils.

The basic element of the present invention shown here is the ability to divide a large number of coils in a confined space by using a combination of coils that are essentially separated from each other. The combination of the loop coil and the butterfly coil are provided so as to be in the same plane with respect to each other and not to be coupled to each other. In this way, the loop coil and butterfly coil extending at least 3 cm in the length direction are placed in a clinically convenient position at an angle from the loop coil, and even if there is a large coupling effect, the image quality is improved. Does not deteriorate. In this way, the coil arrangement is used in a conductive manner with a separable RF system design (ie, for example, a coil located 5 mm closer to the examination site is also located on another side of the body at the same time. There is). In addition, a combination of three or more multi-leaf butterfly coils (ie, a loop coil with two or more intersections) is used in an arrangement that minimizes decoupling. Some of these preferred arrangements in which the butterfly coil was used with the loop coil are shown in FIG.

Combining these coils in the proper arrangement within this modular system provides different opportunities for image optimization for different applications.<u style="single">RF coil housing</u>

The RF coil needs to be built into a housing (40) that protects the electronics from damage and protects the patient from burns and heat. The coil housing also provides an RF shield that can be integrated within the housing. An example of such a coil housing is shown in FIG. 5 (a). Here, the coil (33) is composed of a coil housing (40) containing an electronic device. In this configuration, the central opening (41) of the coil housing provides an access port on which the intervention procedure is performed. A cable (11) extends out of the coil housing, which is common to most coils to connect the coil electronics to the MRI electronics. As an alternative, instead of using cables for the coils, direct electrical / mechanical connections (42) by various potential mounting points on the structure or on the compression plate, as shown in Figure 5 (b). Can be formed between the coil and the cable running to the MRI. Alternatively, an optical signal can be used to transmit the received image information from the coil to the MRI. This is shown in Fig. 5 (c). Here, electrical / optical signal conversion is performed in a coil plate or a structure connected to the coil plate, and the optical signal is transmitted to the MRI through a fiber optic cable or air. This conversion can be performed inside the imaging table top or at a structure connected to the imaging table top. The MRI is equipped with decoding or demodulation means to connect with the optical transmission of the image data and process the image data in the usual way. Each of the illustrated coil housings has the following features. 1) Mechanical attachment mechanism, 2) Means to combine signals with MRI, 3) Liquid impervious, properly clean and sterilized, physical housing to protect electronics and patients.

According to the present invention, the coil housing or tabletop can have a battery or capacitor used to wirelessly operate the coils integrated in the RF system (using, for example, telemetry or optical coupling). If these coils were receive-only coils, a DC voltage would be required to supply the blocking voltage to the coils during image transmission mode, or the power to run an amplifier in the electronics would be is necessary. The coil housing can be provided with a means of connecting to the battery charger, which is provided through the housing to the rechargeable battery inside the housing by electrical coupling from the charger to the coil housing. The battery is then electrically attached to the coil circuit to power the connected amplifier or activate a diode to power the switch circuit. The coil may be powered by a fuel cell, which is recharged in or out of the coil housing.

Coil with cryogenic cooler is replenished with cryogen using this same charging station or another station. To reduce the electrical noise generated by the electronics and coil conductors, the coil housing accommodates or integrates a cryogen confinement device containing a coolant (eg, liquid helium or liquid nitrogen). The cryogenic coolant is gradually lost from the stored housing and needs to be replenished over time. A separable coil with such a cryogenic container will benefit from a replenishment station that replenishes the coil with cryogen (on request or automatically). This replenishment station consists of a cryogen confinement container and a means for supplying it to the coil housing. When the coil is attached to this replenishment unit, the cryogen is replenished through an opening and a sealable valve housed in the coil housing. An additional new concept is the combination of battery charging and cryogen replenishment in a single station. Thus, the charging level of the coil's active components and the cryogen level for cooling the coil can be refreshed in a single step. In addition, coils with such cryogenic coolants can be used for the Seebeck voltage effect to produce a small amount of electrical output. This output can be used to provide coil blocking or to power the signal transmission from the coil directly, or to charge the battery used for these.<u style="single">Coil attachment</u>

The RF coil can be integrated into the coil system by the following various combinations. 1) Inseparable coil embedded in support structure, 2) Inseparable coil embedded in movable structure, 3) Separable RF in coil housing attached to compression frame Coil, 4) Separable RF coil in coil housing attached directly to the support structure, 5) Separable secondary support structure with RF coil. As shown in FIG. 2, the embedded RF coils 1) and 2) above can be directly connected to the MRI connector (12) by conventional electrical connection means. The separable coil of 3) 4) 5) above is a connection panel provided in a support structure (8) attached to the MRI connector (12) by an electrical cable (11) (or other similar means). It is connected to the MRI by (13) or the connection port (14). RF coils attached to moving elements of the system, such as compression plates or second substructures, have the advantage of being able to be located very close to the human body, and as a result can collect large signals. it can.

As shown in FIGS. 5 (e), (f), (g) and 2, the connection points are provided at points easily accessible to the MRI examination technician of the support structure, and are provided at various positions of the main support portion. Has been done. These connections are single or multiple electrical or optical or inductive connections housed within the mechanical support structure. For densely integrated arrays of RF coils, these connectors consist of a number of independent connectors. The RF coil is attached to the connection panel or connection port by multiple means, including: 1) an electrical cable with a termination connector attached directly to the connection panel (preferably a coaxial or similarly shielded connector), 2) a direct provided through an electrical / mechanical connection housed in a coil foam. Electrical connection, 3) Magnetic induction (wireless) connection from coil to connector panel, 4) Optical connection from coil to connector (with or without optical fiber cable).

These connection points provide mechanical integrity and must be impermeable to fluids and easily removed and sterilized if the coil is exposed to fluids or biological contamination. It doesn't become. In addition, these connection points provide a unique physical connection so that only specific coils are connected to specific connection ports as needed.

One embodiment includes a large number of conductors provided along two sets of sliding rails. The number of conductor sets is equal to the number of channels in the MRI system. The present invention is shown in FIG. 5 (h). Here the rail (84) supports the mechanical slider (86). A set of numerous parallel conductors (88), each terminated with coaxial cable (89), is provided along this rail. In the illustrated example, two sets each with three parallel conductors are shown. Each channel corresponds to a set of three conductors, the central conductor being connected to the central conductor of the coaxial cable and the other two conductors being connected to the outer conductors of the coaxial cable. The relative positions and thicknesses of the three conductors are set to ensure impedance matching with the system. In a similar embodiment, a large number of sets of two conductors are used, which are alternately connected to the inner and outer conductors of the coaxial cable. Thus, in order to substantially shield between adjacent channels of MRI signals, it is necessary to use a set of two or three conductors.

The slider (86) is equipped with a brush or spring contact so that it is electrically connected to the parallel conductor set only continuously or only when the slider (86) is locked in place. It has become.

The coil and coil frame (87) support a set of similar parallel conductors (90) provided along different directions. These conductors are located on the outside of the coil housing and are connected to the coil housed inside the housing. These conductors are aligned with the corresponding conductor set housed in the T-slot of the mechanical slider (86). The locking mechanism ensures that the two conductor sets are in electrical contact when the conductors of this slider are locked in place in the coil housing.

Such an arrangement provides a means of mechanically locking the slider and / or coil and electrically connecting the coil (87) and the cable (89) in one action. Regardless of the position of the coil frame in the slider or the position of the slider in the rail, there are numerous electrical connections from the coil housed in the housing to the wires connected to the MRI. In this embodiment, a T-slot and a set of three conductors were used, but various other mechanical and electrical configurations can be used without departing from the spirit of the present invention. A mechanical positioning mechanism allows the connection of cable sets that change position continuously. This allows electrical continuity checks without cable interference while positioning the coil plates and if all plates of the system are locked in place.<u style="single">Coil selection and switching</u>

For bilateral imaging applications, such as chest imaging with a multi-coil array, a means of selecting a coil subset for collecting only MRI signals from the subject is available. In the case of chest images with bilateral contrast emphasized, it is desirable to obtain the individual image volumes independently. Therefore, a means of selecting a coil subset while collecting images of one chest and another coil subset for another chest is preferred. This is also required for imaging applications during imaging or activation of the subject to be examined, and also when it is desirable to activate a transmit coil set that includes only a subset of the total number of RF coils. Will be done.

The method of selecting or deactivating a coil is to electrically activate or deactivate the coil so that the coil circuit is modified, opened or closed, or the coil is removed or reconnected. And includes the step of selecting the coil by mechanical modification of the coil. One means of switching coils for different image configurations involves the physical separation of the coil from the system, especially the removal of the coil and coil housing connected to the MRI. If another coil or coil array is not installed in place of the removed coil, it is designed to detun the termination circuit, open circuit, eg 50 ohms suitable load resistance, closed circuit, or coil. The circuit is automatically or manually connected to the location. This is applicable to coils connected to the system via electrical or mechanical connections, inductively coupled coils and optically coupled coils.

Other coil selection options include electrical deactivation of the coil by a blocking signal (typically a bias voltage) to the detuning circuit. These coils are selected to optimize the total number of coils that image the appropriate volume. The selection of the electrical coil is 1) user selection of the coil configuration file programmed to send the appropriate blocking signal to the MRI, 2) automatic switching based on the external signal generated through the MRI control pulse, eg coil appropriate. Alternately activates and deactivates the coil, either by decoupling it or by maximizing the number of activation signals preferred for bilateral human imaging, 3) by external signals not provided through MRI. User selection. This signal is provided electrically, optically, or inductively. 4) Automatic coil selection based on coil load characteristics reflecting the signal provided by the coil, 5) Analysis of individual signals arriving at MRI and their exclusion or inclusion in reconstruction, 6) Using optical signals Achieved by programmed switching of the coil that was. Do these automation technologies make a positive contribution to the signal to be measured (impedance measurement from the coil, MRI signal measurement, or optical measurement) for each individual coil element for the entire field of view or SNR? I'm asking you to decide. This is of particular importance for chest imaging, where chest size varies significantly and some of the coil subsets do not contribute to the signal for image reconstruction and are therefore non-functional and ignored. Rather than simply ignoring the input of one or more coils, it may be more beneficial to disconnect, disconnect, and deactivate one or more coils. If one or more coils in the array are deactivated, disconnected or disconnected, they will not generate electrical noise to the reconstructed image as well as activated connected coils. In addition, this separation makes it impossible to provide undesired coupling with other coils. In one embodiment of the invention More coils than the number of coils that can be used at the same time are provided close to the medical treatment target. Various means have been used to select the most beneficial coil element from the available coil elements. The coil selection means and the basic concept of deactivating the coil are described above.

Switching with external circuitry and channel multiplexing makes more coils available than the total number of receive channels available on the MRI. For example, a chest coil array consisting of 16 coil elements can be used for 8-channel MRI. Although this concept has been proposed in the prior art, it is not considered as an expandable system as in the present invention and does not envision various embodiments as presented in the present invention. This multiplexing capability is provided in a dedicated stretcher-based or tabletop add-on coil, similar to the electronics inside the MRI. In addition, the switching circuit properly transmits the receive coil signal, transmit signal, and blocking signal for coil deactivation, as shown in the prior art document (US Pat. No. 6,867,593, Menon et al.). Can be integrated to do. Integrating this switching technology within the stretcher is not expected in the prior art and offers enormous benefits.

In addition, mechanical / electrical switches are used to stop the circuit. This is, in the first place, a mechanical disconnection, where the coil is left in place and a switch runs an additional circuit that connects or disconnects the circuit or disconnects the coil from the system. Further, a large number of coils are provided in the coil plate, and when the coil plate is inserted in a specific direction, the specific coil is operated and the other coils are stopped. This may be a gravity switch, which selects and stops a given coil depending on the orientation in which the plate is fixed. Alternatively, the coil can be activated / deactivated by the orientation in which the coil frame connector is introduced into the corresponding receptacle.<u style="single">Coil element array design</u>

A combination of a loop coil, a saddle coil, a transmission line antenna, a butterfly coil, a dipole, a solenoid coil, and an opposing solenoid / self-induction coil can be used in the present invention. These coils can be used as a phase array or as a quadrature or circular deflection configuration. In a preferred embodiment, a large number of coils are selected based on a size suitable for the patient's human body, and each coil images a subvolume of the entire image volume substantially independently. .. In this method, the combined signal-to-noise ratio from all coils is maximized. In particular, the combination of a loop coil, a butterfly coil and a transmission line coil provided on the same plane or on adjacent parallel planes forms a field orthogonal to each other in most places. Having a field that is approximately orthogonal helps reduce inductive coupling between the coils. In this method, the coils are tightly mounted and cover the imaged volume without interfering with each other, producing an optimum SNR.<u style="single">Individual coil structure</u>

The signals from the individual coil elements can be combined as a phase array, quadrature or circular deflection configuration. In a preferred embodiment, interchangeable coil plates with coils are shown in phase arrangement and quadrature phase configuration in different arrangements and in different orientations. The placement of the coils on these plates affects the overall detection sensitivity profile and the field of view of the combined coil array. Therefore, coil size, position, phase and orientation need to be considered to optimize overall sensitivity, field uniformity, field coverage, coil coupling and parallel imaging characteristics in the overall coil arrangement. .. FIG. 6 shows a large number of loop coils (36) provided with the movable coil plate (40). For chest imaging, a set of four loop coils with the long axis oriented in the Y direction (corresponding to the patient's anterior / posterior direction) is shown in Figure 6 (a). Prior art has not shown this for chest imaging. The polarity of the field due to each coil points in the same direction. By slightly superimposing each coil, adjacent coils are decoupled. In FIG. 6 (b), the direction (polarity) of the field is reversed for each coil. In this method, the magnetic flux or magnetic field formed by the combined coils decouples more effectively in some arrangements. A coil array similar to FIG. 6 (A) is shown in FIG. 6 (c). A coil (35) that is smaller only in the height direction is used. Here, the aspect ratio of height to width is about 1: 1, while the aspect ratio of the elongated coil in FIG. 6B is 2: 1 or more and 5: 1 or less. FIG. 6 (d) shows four coils (36) in which the coils are arranged horizontally, and the major axis directions of the coils are aligned with the major axis directions of the coil plate. FIG. 6 (e) shows the arrangement of the four butterfly coils (37). As shown in FIG. 6 (f), these butterfly coils can be aligned with the loop coil, which creates a unique field for better parallel imaging.

The loop and butterfly coil can be superposed so that the magnetic fields are orthogonal to each other. In this method, eight densely mounted coils provide a unique imaging field of view. As shown in FIG. 6 (h), these coils can be arranged so that the long axis of the coil is aligned with the long axis of the coil plate. As shown in FIG. 6 (i), the transmission line coil (38) can be provided so that its length direction is along the main magnetic field direction of the magnet. These coils can be varied in length to fit the contours of the compressed chest. These concepts have not been shown in the prior art and are new. Alternatively, it can be used as a loop coil configuration in which the transmission line coil is not closed. Such a coil is shown in Fig. 6 (j). By using the transmission line coil as an open loop coil, the coil operates so that the magnetic field points in one direction in the same manner as the single loop coil. Since the magnetic fields of the transmission line coils can be directed in one direction, this arrangement has the advantage that these coils can be used as an array when the coils are facing each other on the ground plane.

The loop coil and the transmission line coil can be combined to form a dense array of coils, as shown in Figure 6 (k). In addition, the butterfly coil, loop coil, and transmission line coil can form 12 coil arrays with relatively independent magnetic fields. This tightly mounted coil arrangement provides an optimally sized coil arrangement for the subject to be examined and also provides a large acceleration factor for parallel imaging.

Array configurations with different phases have been utilized for cardiac coil systems in which two rows of coils are used to provide bidirectionally accelerated parallel imaging (eg, SENSE) along the coil plate. Chest coils have been provided that combine a number of loop coils with butterfly and saddle coils, but in a fixed arrangement where the position and type of individual coil elements cannot be changed (Qu et al, US Patent Application Publication Number). It was 2005/0104591A). In addition, coil systems have been provided in which individual coil elements are combined in a linear arrangement (Vij, US Pat. No. 6,498,489). However, no attempt has been made to separate the imaging from the coil support function. Also, there was no attempt to separate the coil sets from each other. In addition, none of the coil arrangements shown in FIG. 6 has proposed an image context with plates provided on opposite sides of the image volume.

The TIM system developed by Siemens Medical combines a number of coil elements, some of which are embedded in a patient support table. The MRI system actively blocks and detuns some elements of the coil array. This is a very different concept from what has been proposed. In addition, the TIM system is a general purpose RF system design with a general purpose table top that has been developed to handle all possible imaging applications without specifically providing optimized coil placement or position. .. For applications such as chest imaging, a dedicated support structure utilizing a modular coil arrangement is required.<u style="single">Coil array configuration</u>

The coil plates are preferably centered / side-mounted, as shown in the axial view in FIG. Figure 7 (a) shows the application of a unilateral chest image. Here, one breast to be treated is fixed and compressed between two compression plates that can be adjusted left and right and can be locked in an appropriate position, and the other breast is the opposite breast support. Is being squeezed towards the chest wall. In FIG. 7 (a), the central coil plate (47) and the side coil plate (24) are supported by a pair of compression plates. The ability to move these coil plates closer to the chest greatly improves coil capacity. Although such coil configurations have been shown in the prior art, details of the various shapes of these coils have not been disclosed (Piron et al, US Patent Application Publication No. 2005/0080333). The application presents details of the coil arrangements that can be used with the configuration and, in addition, discloses arrangements with various coil arrays that extend this concept to allow for advanced coil decoupling. ing.

A bilateral coil arrangement is shown in FIG. 7 (b), where two side compression plates (24) contain the coils and two central compression plates contain the coil plates (47). .. An additional anterior coil plate (23) is attached to the compression plate or main support structure (8), as well as a posterior coil plate or coil structure (46) that is provided towards the sternum and has an opening to accommodate the breast. be able to. These coils can be moved relative to the support structure. In a preferred embodiment, the center / side coil moves primarily left and right, while the front / rear coil moves primarily up and down. It is also desirable for the central-side plate to have a small anterior / posterior adjustment range (up to 30 cm for the standard chest image) and a lateral adjustment range for the anterior-posterior coil (relative to the standard chest image). It is also desirable to have up to 50 cm). For bilateral imaging applications, a four-part side-central compression plate compresses both breasts. Additional support can be provided by the sternum support (15), which may or may not contain an RF imaging coil. In this arrangement, a total of eight coil plates are provided to cover the imaging areas of both breasts. In addition, the coil can be attached to other coils in the system by mechanical connection. This introduces the coils to well-defined locations in the array and improves decoupling between the coils. The connections are made in different right / left positions so that the different electrical connections are associated with the unique mechanical positions so that the unique decouplings and electrical connections are made.

The coil plate can accommodate a transmit, receive, or transmit and receive coil and a combination of these coils. In FIG. 7 (c), the two posterior coil plates (48), the sternum support (15) and the two central coil plates (47) are combined into a single support, which is an imaging structure. This central support structure can be removed from the main support if necessary to ensure access to the entire breast. The central support structure may be hollow so that various RF coils can be attached while the patient is still on top of the structure.

Here, the central compression plate does not house the central coil plate. Instead, all RF antennas are centralized in this central support structure. This embodiment may have coils on each central surface, sternum surface, and posterior structure. In this arrangement, the coils cannot move relative to each other, but can be separated from each other using prior art. It can be extended to include any combination of coil plate and support structure.

Figures 7 (d), (e), and (f) show alternative coil arrangements. Here, the function of pressing the chest and the placement of the coil are separated. An example of unilateral coil arrangement is shown in Fig. 7 (d). A side coil (24) is attached to the center coil (47) by a connecting member. These connecting members include i) an electrical connector that completes the circuit on the side or center coil array to activate for imaging, and ii) side and center for the purpose of separating the side and center coils. The coils are connected and iii) contain additional coils or coil segments used to serve the activated coil array.

In addition, coils located anterior or posterior to the chest can be integrated at positions fixed relative to sign (24) and sign (47). In this method, the coils are placed in known positions with respect to each other and decoupling strategies such as inductive or capacitive decoupling can be used to reduce coupling interactions between all coil elements. A compression member can be attached to a member connected to the side and center coils so that the chest can be compressed without moving the coil. In Figure 7 (e), a bilateral implementation extends this concept by attaching the side coil (24) to a large central coil containing coil elements located posterior and central to the chest, with a compression plate. It is designed to move against the coil so that it can be compressed as needed. In FIG. 7 (f), the rear coil is integrated with the center coil. In this arrangement, all coils are located in known positions with respect to each other and are therefore properly decoupled. No compression plate is shown in this configuration. The ability to attach a large number of coil subsets to the main coil set attached to an MRI is a new and basic concept.

In all embodiments, the side coil, center coil, front coil, or rear coil is interchangeable with other coils so that each coil is provided to be appropriately sized for the shape of the chest.

The coil structure proposed in FIG. 7 allows the coils to be placed near the chest or to wrap the chest with a large number of coils for various imaging applications. In addition, these coils can be removed or replaced with coils of the appropriate size for the medical subject to be imaged. Different sets of coils include kits that allow imaging of different chest sizes. In one embodiment, a unilateral imaging coil and a bilateral imaging coil are provided. Another embodiment comprises unilateral and bilateral coils provided in different sized coil sets including the following options: In one embodiment, a coil sized for a medium sized breast is provided. In other embodiments, coils of two sizes are provided, one for the middle and one for the large breast. In yet another embodiment, three breast coils are provided for the small, middle and large breasts. In yet another embodiment, coils of three or more sizes are provided. The size of the coil varies mainly in the anterior / posterior direction with respect to the surface coil housed in the middle and side plates. As an example of sizing, the size range of these coils in the anterior / posterior direction is 20-25 cm for large coils, 20-15 cm for intermediate coils, and 15-7.5 cm for small coils. The appropriate size of the anterior / posterior coil is 15-25 cm and varies by more than 50% of the total size according to the division from small coil to large coil.

In another embodiment, one of these chest coils has a configuration optimized for mastectomy images. In this configuration, the coil is located on a plate parallel to the chest wall. The field of view of these coils is 20-35 cm, depending on the size of the patient. The optimum arrangement is that the depth of the field of view of these coils is shallow and does not penetrate deep into the chest wall region, and the ratio of the field of view to the image depth of the coils is preferably 5: 1 to 20: 1. In order to cover this field of view, various coil arrangements including a set of butterfly coil, loop coil, and transmission line coil are used, and an example of the combination is shown in FIG. Preferably, the loop coil in the array is vertically longer than horizontal (at least 2: 1 aspect ratio), oriented in the major axis direction of the principal magnetic field, and parallel to the chest wall. The butterfly coil preferably has a major axis oriented in the patient's left-right direction, while the transmission line line coil or stripline coil has a major axis along the main magnetic field direction.

These coil plates are provided straight or bent to match the chest. The patient is supported by the main structure of the bed so that the breast removal area or surgical scars are supported. Alternatively, these plates can be made with a flex circuit, such as a chest-matching coil. The concept of using kits of different sized coils is unique and has not been shown in the prior art. There was no suggestion of using a special coil for breast removal images.

This concept of a modular coil plate with an imaging array is shown in Figure 8. Here, the set of coil plates consists of four movable plates (Fig. 8 (a), (d), (g), (j)) or two movable plates and one central fixed array (Fig. 8 (b)). ), (E), (h), (k)), or one central fixed array and two mountable side plates (such as Figure 8 (c), (f), (i), (l)). Can be provided in. In each of these shapes, loop coils, butterfly coils (with two or more loops), saddle coils, transmission line coils and other coils can be integrated. In FIG. 8 (a), both the central plate and the side plates are movable relative to each other. Two large side loop coils and the opposing central butterfly coil are shown in Figure 8 (a). This combination ensures a minimum decoupling between the side and center coils. In addition, the central coil may consist of transmission line coils, in which case the opposite ground plane of the central coil ensures that these coils are not coupled, thus improving the properties of the coil array. .. Alternatively, the butterfly coil can be used as the side coil and the loop coil can be used as the center coil. Alternatively, one butterfly coil can be used as the side coil and one as the opposing central coil, while a loop coil can be used on the opposing surfaces of these butterfly coils. By this method, all coils are decoupled.

An alternative arrangement is shown in Figure 8 (b). Here, the central coil is attached to some structure using a circuit and is superposed or decoupled. In this configuration, the central coils cannot move relative to each other. In the alternative configuration of FIG. 8 (c), the center coil and side coil are immovable with respect to each other and are instead locked to each other. The planar shape is shown in FIG. 8 (c), but the side coils are curved in FIGS. 8 (f), (i), and (l).

Although four coils are shown in FIGS. 8 (a), (b) and (c), six coils are used in FIGS. 8 (d), (e) and (f). A preferred arrangement for FIGS. 8 (d) and 8 (e) is two side loop coils decoupling with each other and one large central butterfly coil facing each loop coil on each side of the chest. The central butterfly coil allows one loop to be larger than the other and to expand and bend towards the chest wall. The lateral coil should be provided more posterior to the central coil so that it can be accessed on the patient's chest wall and axis. The use of a butterfly coil that has an asymmetric loop and bends towards the chest is a novel invention, never disclosed in the prior art. This is essential in properly imaging the sternum area.

In Figure 8 (f), the central coil is decoupled by overlapping, while the side coil has two large openings to allow access to the chest. In this arrangement, the side coils are attached to the central coil at a number of connection points. These connection points are used to select the active coils in the central array, which are selected based on which coils are used laterally. Alternatively, these connection points complete the coil shape by adding conductor elements to the central or side coil array through the connection process of the central and side sections.

Figures 8 (g) and 8 (h) show an arrangement consisting of three lateral coils and eight coils using one central butterfly coil on one side. FIG. 8 (h) shows an asymmetric butterfly coil in which the rear coil is larger than the front (lower) coil. In this method, the side coil and the center coil are decoupled when the side coil is located behind the butterfly coil. Modifications of such an arrangement include i) superposition of the central and outer coils beyond the required amount using corrective inductive or capacitive decoupling, and ii) required inductive or capacitive. Accurate superposition between the outer and center coils without decoupling, iii) Decoupling the side coils with respect to each other by subdued superposition using corrective inductive or capacitive decoupling. There is.

FIG. 8 (i) shows a configuration in which two central coils are provided on one side together with a large number of coils housed in the side coil attachment. In this arrangement, several connection points that are structurally and electrically connected are shown above and below each side, along with additional connections in front of this arrangement. In this way, a number of electrical connections are made between the side and central arrays. Any number of connection points can be used and is not limited without departing from the spirit of the attachable coil.

Figure 8 (j) shows two side coils and two center coils. The side coil and the center coil are slightly overlapped and decoupled. All combinations of loop coils and vertical butterfly coils are essentially decoupled in this arrangement. In FIG. 8 (k), eight central coils and eight side coils are provided on one side. This arrangement can be easily expanded to accommodate a large number of vertical loop and butterfly coils. In this arrangement, each coil covers the chest in the anterior-posterior direction, while allowing parallel imaging in the left-right and up-down directions. The two parallel imaging orientations are best suited for chest imaging in the prone orientation. Figure 8 (l) shows the final figure of a mechanical / electrical connection approaching from the front so that the patient is not pinched when the coil is connected.

In addition, very high density coils can be used in the proposed coil arrangement. The addition of coils in the posterior region with a large opening for access to the chest and / or the addition of coils in the anterior region provides a variety of alternative coil arrangements within the illustrated coil configuration. Ideally, the magnetic flux lines associated with the coils on these coil arrangements would be the main magnetic field of the MRI (B).₀) To maximize the correction of the MRI signal.

A bilateral arrangement is shown as an example of a high density coil arrangement that can be used with a 16-channel MRI system. Here, eight butterfly coils are provided on the central coil plate or the central sternum support. Eight loop coils are provided across these butterfly coils. This is repeated on both the left and right sides of the chest. These coils are longer in the forward direction than in the upward direction and are pairwise decoupled from each other on their respective coil plates. In a unilateral arrangement, 16 coils can be used per coil plate. These coil sensitivity profiles can be differentiated by slightly varying the placement of the coils to optimize imaging for parallel imaging. This is achieved by modifying the butterfly wiring by increasing the width, height, or angle of the conductor wiring.

This arrangement is free to scale up or down from 1 coil per coil plate to 16 coils per coil plate while maintaining sufficient penetration into the chest tissue for clinically relevant visual fields. Can be done. This provides a very highly parallelized arrangement that can be used for chest imaging. Alternatively, the transmission line coil can be used as a hybrid loop coil instead of the loop coil described above, or the transmission line can be used in a linear configuration in combination with the loop coil. Examples of these variants are shown in FIG. 6, but these are examples in the context of a modular array system. In addition, when a loop coil and a butterfly coil are used as the right-angled phase pair, the signal-to-noise ratio is improved as compared with the case of a single signal line.

It should also be noted that in all cases, curved or equiangular coil plates can be used without departing from the spirit of the present invention. Such plate placement is also useful when imaging other parts, such as knees, elbows, wrists, and ankles. Replacing these coil plates provides all the benefits discussed so far for chest imaging. Because this supports or immobilizes the clinical site, advances to the scan position for imaging, returns to the home position (outside the magnet), removes the coil plate to access the examination tissue, or replaces it with another coil plate. This is because it is possible to re-image for image optimization and to take additional images or insert an intervention device without moving the clinical site from the initial imaging position. ..

Choosing a coil subset as the transmit coil and the other coil as the receive coil offers great benefits in imaging applications where SAR limitations need to be taken into account (What is a specific absorption rate (SAR)? It is the rate of energy application to the examination tissue by the RF pulse transmitted from the MRI. Transmission using a relatively small local coil reduces the temperature rise of the human body tissue compared to exposing the entire body to the RF pulse.) In one embodiment, the front and rear coil arrays can be used as transmit coils, the combined magnetic fields provide a substantially uniform transmit magnetic field, while the center and side coils can be used as receive coils. The roles of the coils can be reversed, in which case the front and rear coils receive and the center and side coils transmit.

The imaging methods presented herein can be implemented with any combination of plate arrangements. These plates can be provided to move with respect to each other or to be fixed. In a preferred arrangement, these coils are provided as close to the examination site as possible, while minimizing the coupling between the coils. Coupling can also be minimized by making the size of the coil appropriately the size of the part to be imaged.

An alternative embodiment of a reconstructable coil array comprises a number of layers of conductive traces isolated from each other. These traces make up individual coils with accompanying capacitors, inductors and blocking circuits, with the various coils present on a single plate. These coils are loops, butterflies, opposed solenoids, or transmission line line coils. In this embodiment, one or more of these coils are simultaneously selected and provided with a means of signal connection, while many other coils are electrically open, detuned, or blocked. It is unusable because it is short-circuited or electrically short-circuited. The coil selection means includes a mechanical switch or an electrical switch of the conductive path at the coil end or the MRI end of the signal coupling means.

In addition, mechanically attaching the coil plate to a fixing means, such as a compression plate, activates or deactivates the selected coil element on the coil plate. The fixing means brings about this activation and deactivation with a mechanical key or electrical plug that connects some coil elements and detuns, terminates, or blocks others.

The electrical connecting means of each coil is an interface with a receiving connector integrated in the mechanical fixing means. The connector pair is oriented so as to determine which coil element is active and / or the polarity of each coil. For example, if the coil plate is rotated 180 degrees before being plugged in, the output polarity of the coil will be reversed. There are means in connectors and blocking networks to ensure that the blocking signal used with the receive-only coil always has the correct polarity. Rotating the coil plate 90 degrees before connection (eg from the direction of the arrow on the coronal plane) has the effect of activating different coil elements within the coil plate. The coil element produces a sensitivity profile suitable for the orientation of the plate and its position relative to the clinical site.

Replacement of these coil arrangements for different imaging applications in the chest or other reconfigurable examination sites can be used to optimize SNR and field of view for: i) Bilateral clinical site image-Maximizing the number of coils for bilateral sites and optimizing their sensitivity profile ii) Unilateral clinical site image-Maximization of the number of coils in a single site and optimization of its sensitivity profile iii) Intervention Procedures-Maximizing the number of coils and optimizing their sensitivity profile while providing appropriate physician hands and gaze and access to interventions and imaging devices. iv) Imaging of clinical sites in different structures-maximizing the number of coils at reconfigurable clinical site positions and optimizing their sensitivity profile<u style="single">Medical treatment site position</u>

The patient's chest is imaged in various shapes by compression from various directions. This concept can be extended to other sites found to be suitable for clinical or diagnostic needs. That is, it is desirable to obtain an image of the structure of the site with the optimum image quality for one and a surgically expressed image for the other. As shown in FIG. 9 (A), the chest is compressed toward the chest wall using a compression plate (18) that is movable in the anterior-posterior direction. The plate shown in this figure also provides an opening covered with a compression membrane (53). A coil is inserted in this plate as shown in FIG. 9 (b). Good immobilization and high signal-to-noise ratio can be obtained by moving the compression plate containing the coil near the chest. The chest can be accessed for other imaging means by removing the coil plate (23), provided that the compression membrane is sufficiently permeable to the other imaging means. For example, if an acoustic membrane is used, an ultrasound transducer can be used for chest imaging, while the four sides of the chest remain accessible for intervention purposes. This concept is shown in Fig. 9 (c) as an axial view for bilateral applications. Figure 9 (d) shows the figure in the direction of the arrow. An alternative embodiment of the compression plate is shown in FIG. 9 (e). Here, the compression plate is composed of a swivel diagonal member. Each of these compression plates is provided with one or more openings to which the coil plate can be fixed and one or more compression membranes (to which the coil can be detachably fixed). This situation is shown in the arrow direction diagram of FIG. 9 (F). The advantage of this arrangement is that the chest is more fully fixed and the immobilization system can support a large number of and diverse coils. The compression plate also supports an isometric plate so that the chest is compressed more evenly.

Another advantage of the proposed system is the ability to support isometric plates or immobilization devices. As an extension of the compression plate that can be adjusted in position and orientation, an isometric immobilization plate (56) or compression membrane (eg, a thermally set mesh) is used, eg, as in FIG. 10 (a) used in surgery. It can be placed on the chest while the patient is in the supine position. This patient's chest position can be maintained while the patient rotates to another position, such as the prone position, and is located in a main support structure with a dedicated stretcher-based coil or tabletop add-on coil. The open structure of the system provides the addition of such an isometric fixed structure. An imaging coil set is placed on these plates as a coil supported by the oblique compression plate (72) shown in FIG. 10 (b) or as an equiangular arrangement of coils supported on an equiangular immobilization plate (56). Can be added. A similar arrangement is shown in the arrow direction diagram in FIG. 10 (c). Here, the oblique compression plate is movable up and down and is rotatable.

The ability to position the chest in two different structures while the patient is lying on the main support structure is important when intervening in MRI and requires imaging for preliminary surgical determination of the breast cancer area. It is important in such cases. To obtain an MRI image set while in standard imaging orientation (ie, if the patient is prone and non-compressed, or if the patient is prone and medial / laterally compressed), and during surgery (patient) The rearrangement must be performed so that the image set can be obtained in the same position (on the back). In this way, tumor positions are correlated with each other, either between the two positions or between the two end positions. These two imaging positions can also be used to ensure that the positioning wire or other surgical marking device is in the correct position for minimally invasive treatment of the cancer. This is shown in FIG. 10 (d). Here, the chest compressed in the central / lateral direction is shown in the axial view, and the positioning wire (58) is located through the target lesion tissue (57). Figure 10 (e) shows how all the coils and compression plates are removed and the chest is freely manipulated on the device. As shown in FIG. 10 (f), an anterior isometric compression plate can be introduced so that the chest is compressed to the same shape as during mastectomy and the coil plate is provided near the chest for imaging. In this method, the chest can be compressed in a preferred direction for a particular clinical application and the RF coil can be placed as close to the chest as possible to obtain high SNR images.

Although the present invention is specifically represented in the drawings for chest imaging applications, it can also be used for other sites where bilateral or unilateral imaging is preferred, and patient support and fixation in a coil system. It can be used in any situation where the conversion takes place independently.<u style="single">Dedicated body imaging application</u>

Another example to which the methods and devices of the invention are applicable includes body imaging applications. In this application, a dedicated body imaging stretcher (61) with a large intervening volume provides an access point where modularized support structures and coil arrangements can be provided or removed. Applications of this system include imaging of the heart, lungs, musculoskeletal system, spine, liver, kidneys, as well as intervention images of those sites. In FIG. 11 (a), the patient (4) is supported by an MRI body support structure (60) and the anterior plate (62) and posterior plate (63) are used to place the coil near the patient. Various coil arrays can be introduced using coil plates in a manner similar to chest imaging applications. A large field of view coil array (64) and a small field of view coil array (65) commonly used in larger SNR imaging applications are shown in Figure 11 (b). As shown in FIG. 11 (c), the coil plate is inserted into the support plate. In FIG. 11 (d), the coil array with a small field of view is introduced into the large coil array, properly located on the target site and imaged with a high signal-to-noise ratio in the target area.

In addition, coils corresponding to different frequencies optimized for a particular imaging application can be easily replaced while the patient is in the same position. For example, in contrast to the imaging of the lungs, the coil array is required to image the contrast of the blood flow as well as the image of the hyperpolarized gas for the imaging of the aeration. For cardiac applications, coils are provided to excite or image specific species associated with novel endovascular contrast agents. Both coils can be appropriately tuned to detect or excite a particular species of interest. Additional side plates or diagonal plates can be integrated into the device as needed. These plates provide lateral support for the patient, provide attachment points for probes and devices, and provide additional attachment points for the coil system for improved imaging. In addition, the support plate provides access openings and / or guide means for intervention and imaging with other imaging means (X-ray, ultrasound, optics, infrared, etc.). A dedicated stretcher / special purpose tabletop system and modular placement of sub-components provide all the benefits realized for chest applications.

Alternative embodiments of the invention can be extended with similar concepts to prostate, gynecology, colon imaging and intervention. In another embodiment, the sheath concept can be used for intravascular imaging, intraoperative imaging, and the like. As shown in Figure 12, the prostate stretcher and tabletop system are used for different stages of the same imaging / intervention procedure, for different patient procedures, or for different types of procedures. It provides additional access that allows the modular coil and patient support device to be reconstructable. A major distinctive feature is the addition of a support device that can be inserted inside the patient. This support device (not shown) is composed of an arm with an indirect or a support that holds a sheath or a body introduction device. By keeping this sheath in a fixed position, various coils and devices can be inserted while keeping the patient and other devices in a fixed position. This is shown in FIG. 12 (A). Here, the front coil support (62), the rear coil support (63), and the internal coil sheath (68) all support a variety of coil arrangements. Depending on the application, various coil plates can be introduced into these support / immobilization stretchers. The anterior plate (62) holds the patient's buttocks in a fixed position and provides mounting means for the coil array. This is achieved by a support arm that maintains the position of the anterior coil and prostate sheath to hold the patient in a fixed position. The prostate sheath provides an intervention access port that is permeable to various imaging devices, such as ultrasound, and facilitates intervention in the prostate.

The sheath (68) is made of a flexible, expandable membrane. In this method, the probe can be inserted into the sheath, inflatable and mechanically expandable to secure the peripheral site. In certain applications of prostate imaging, the hard plastic wall of the probe needs to expand and press against the rectal wall. In this method, the coil can be provided very close to the prostate to maximize signal collection. In addition, if the plastic is made of a material that is very close to human tissue, there are no harmful image artifacts that affect the prostate area. In addition, holes or openings can be provided in the center of the coil, or in the outer region of the coil, to release gas during the procedure, thus comforting the patient and limiting peristalsis.

According to the present invention, numerous techniques, procedures and methods make use of the embodiments of the present invention, as shown in the specific examples below. -Bilateral imaging with all available channels. -One-sided imaging with all available channels. -Intervention imaging with coils selected to provide open access. -Chest non-compression, central / lateral compression for fixation for better imaging, chest wall compression, or oblique chest imaging (bilateral or unilateral) (compression to improve imaging) (That is, to reduce movement), to reduce movement during intervention, to match the chest position to the surgical position, and to match other image positions (ultrasound, X-ray, CT)). -Imaging while exchanging with other coils of the desired frequency-ie, high magnetic field (3.0T), spectroscopy (Na, C)₁₃, F et al.) Or match the species associated with the new contrast agent. In the lung cancer imaging example, the coil is tuned to hydrogen to enhance contrast and is replaced with a coil tuned to hyperpolarized gas to image the aeration cycle. -Replace the coil with a coil that matches the size of the clinical site and image it, for example, adapt the coil size to the chest size. -In the preferred imaging application, imaging by replacing the coil with a larger acceleration factor. -Imaging by replacing with a new coil that supports a larger number of data channels available for MRI while maintaining the same patient support or dedicated stretcher design. -Instead of replacing the entire system, replace the non-functional coil with a functional coil for imaging, or in the case of a cryogenic cooling coil, replace the coil with a coil containing a chilling agent, or a wireless coil. In the case of, replace the coil with a charged battery, and in the case of a sterilization coil, replace it with a disinfected coil for imaging. -Dedicated body imaging Imaging and intervention for body applications using stretchers and power strips. -Imaging and intervention for prostate use with a dedicated prostate stretcher and power strip.

The above description of the present invention is not intended to describe all objects, features, merits and practices of the present invention. Although the description of the embodiments of the present invention focuses on chest imaging applications, one of ordinary skill in the art will appreciate that the present invention is also available for other parts of the body. The main difference is the shape of the coil and its relative positional relationship. The basic concept of patient support, site fixation and separation from the RF system has a wide range of benefits.

All patents and printed publications referenced herein are incorporated herein in their entirety by reference.

Numerous techniques, methods, devices, and systems have been proposed to improve the imaging of human tissues using MRI. As included in, but not limited to, the present invention - A coil independent of the support structure and Replaceable coil and Coil that can be installed at various positions near the patient's medical treatment site, -Coils embedded in secondary structures such as repositionable compression plates A new architecture for RF imaging systems with. -Technology and mechanism for replacing coil systems that are separable from patient support. -A new compression mechanism suitable for compressing the clinical site in various orientations and shapes. -Replaceable compression system. - Inserting and fixing the coil, A film that is transparent to various imaging devices and Intervention and access to imaging equipment, A compression system with an opening that allows for. -A replaceable coil system with various options for coil signal transmission, including cable, inductive coupling, optical transmission, remote transmission. -A replaceable coil with integrated analog-to-digital conversion capability so that digital information can be carried from analog via cable connection or remote connection. -New coil placement for densely mounted coil arrays with a combination of loop coils, butterfly coils, saddle coils, opposed solenoid coils, and transmission line coils. -Secondary support structure that provides optimal patient position, support and immobilization options. -Secondary support structure with integrated RF coil or means to attach the RF coil. -Cable wiring that keeps the cable out of contact with the patient. -Coil charging using an external charging module for coils that require a battery. -A coil that uses the received RF energy to charge the energy storage device. -Coil cryogen replenishment using an external filling module when the coil is cooled to a very low temperature.

The advantages of such a system are -Improved SNR by getting more coils and more appropriately sized coils closer to the patient's clinical site. -Different coil systems for parallel imaging applications that give the user flexibility for imaging or intervention therapeutic or diagnostic imaging applications. -While keeping the patient in the same position, the coil has different images: 1.5T, 3.0T, Na, K, C₁₃Flexible imaging to replace for. -Reduced downtime by replacing only one coil plate or coil element without having to replace the entire coil system due to one defective coil. -User-upgradable systems, such as MRI upgrades, which require only the subsystem to be purchased for the coil system, as opposed to a brand new coil system with an accompanying housing / patient support structure. -The ability of the patient to image the chest in various compression shapes with minor structural changes while being kept in the same position on the device. Time is critical in this application because the injected MRI contrast agent needs to be imaged while providing image contrast. This leads to the ability to represent contrast-enhanced lesion sites under various compression conditions with a single contrast injection. The various compression states include: Non-compression Center-side compression Forward / backward compression Diagonal compression Isometric fixation and chest compression -The ability to physically remove and replace the compression and coil systems while the patient is being maintained on the device. This allows for additional imaging and advanced access to the imaged site for intervention or treatment. This is possible if there is an opening provided in a dedicated table top with a dedicated stretcher base.

The techniques of the invention have a patient support structure with at least a connected or continuous area supporting the patient's head, chest, abdomen and legs, the patient support structure for at least one patient. It has a support structure component that accommodates and releases an adjacent RF coil system, with at least one support structure component delivering at least one RF coil to one or more of the patient's head, chest, abdomen, and legs. It is possible to install them adjacent to each other. The patient support structure contains at least one of the female breast, female genitals, and male genitals, and has at least one specific support structure component for a coil placed close to it. At least one specific support structure component for a coil located in at least one position of the patient support structure that houses at least one of the female or male chest, female genitals, prostate, colon and patient's torso Exists. At least one support structure component has a guide support that allows coils of different structures to be inserted into a support that has common guide engagement features. The patient support structure has at least one support structure component having a guide support that allows the coils of different structures to be inserted into the support that has common guide engagement features. The patient support structure has a coil structure with an engaging member connecting a communication port, a material flow port, and a power port on the patient support structure. The patient support structure comprises a stretcher mounted on a wheel, which has an engaging member that engages the stretcher's RF coil system with the MRI's RF system. The patient support structure has a specific location to accommodate the female breast, the location is adjustable for different sized breasts, and an RF coil system that assists in MRI imaging of the breast located at that location. However, it is removed and replaced, leaving the chest in place without moving the compression system in contact with the surface of the chest. The patient support structure is selected from a group consisting of receive antennas, transmit antennas, and transmit and receive antennas. It has coils with different functions, and these antennas are interchangeable in a combination of antennas adjacent to the location. The patient support structure has at least one location with a combination of transmission line coils distributed around it, the transmission line coil being long in the anteroposterior direction and provided with a loop coil and a butterfly coil, a). Alternating patterns of facing plates, b) facing structures, and c) coplanar with the plates are formed. The patient support structure has at least one RF coil set with at least two or at least four movable sides and a central coil plate that essentially accommodate the decoupled coils.

The patient support structure is a) a vertical butterfly and loop coil, b) various transmission line coils with loop coils, c) transmission line coils and butterfly coils, d) multiplex in combination with loop coils or transmission line coils. Coil with essentially decoupled or essentially decoupled coil selected from the group consisting of loop butterfly coils, a) horizontal butterfly and loop coil, b) loop It is selected from a group consisting of various transmission line coils with coils, c) transmission line coils and butterfly coils, d) loop coils or multiple loop butterfly coils combined with transmission line coils. The patient support structure is at least 1) Direct electrical connection 2) Brush or slide mechanism / electrical connector 3) Magnetic induction connector 4) Signal transmission It has an RF coil that allows signal transmission from the RF coil attachment of the patient support structure to the MRI cable using one of the.

The techniques of the present invention include a step of supporting an object on the patient support structure of claim 1, a step of adjusting the location of the individual object, and at least one RF coil set adjacent to the adjusted location. The step of positioning and the step of moving the support to the hole of the MRI, It includes a step of providing MRI data of an individual object highlighted by data derived from at least one RF coil, and a method of performing an MRI imaging process on the individual object having. In this method, at least one RF coil set engages the MRI RF system while the support moves into the MRI hole, or thereafter. The stretcher's RF coil connects to the MRI's RF system in automatic communication. In this method, the coil is selected from a group consisting of automatically tuned coils in the stretcher, a preamplifier in the patient support structure amplifies the received signal, and an electrical shimming coil MRIs the RF signal by wireless transmission. An additional step is performed of transmitting to an external receiver and cooling the coil inside the patient support structure to a cryogenic temperature during MRI imaging. The patient support structure has at least one set of receive, transmit and transmit and receive antennas, which are interchangeable in at least one location.

The technique details specific coil arrangements, means of connecting these coils, and the use of these coils for specific imaging purposes. In addition, the concept of replaceable coils has been extended to include the use of electricity charging stations and the use of cryogenic filling stations for cryogenic cooled coils. In addition, the system allows electronic devices to be embedded in patient supports and stretchers, such as automatic coil tuning, received signal preamplifiers, electrical shimming coils, wireless signal transmission devices, and ultra-low temperature cooling systems for coils. It facilitates advanced image applications such as.

The RF antenna set has an interchangeable coil, which is tuned for different image types at a particular magnetic field strength and also for different magnetic field strengths. In addition, the RF antenna set has a replaceable coil, which is a coil. Small chest size Middle chest size Large chest size Battlement It is tailored to the size of the patient's clinical site, including the coil for.

As RF antennas, some loop antennas, transmission line antennas and / or butterfly antennas are used as a set. The coil configuration and the combination of configurations shown here are unique. The use of a butterfly coil facing the loop coil or a coil array on separate plates that are essentially decoupled from each other, with loops and transmission line line coils, is novel. Alternating combinations of vertically (longitudinal directions in the front-rear direction) and butterfly coils on opposite surfaces, on opposite structures, or on the same plane are also new combinations of coil arrangements. This arrangement is essentially decoupled. The terms "decouple" and "essentially decouple" are well understood in the field of RF coil technology. The term is taken to mean that the magnetic fields resulting from coil stimulation do not interfere sufficiently with each other. With respect to the arrangement, the magnetic fields do not face 180 degrees and the strength of each magnetic field is at least about 50%, preferably at least 70%, more preferably at least 85% as a single field in the absence of other magnetic fields. , Most preferably at least 90% or 95%. Alternating combinations of loop coils and butterfly coils provided on the transmission line line coil (longitudinal direction comes in the front-rear direction) on facing surfaces, facing structures, or on the same plane are also new combinations of coil arrangements. Is. This arrangement is essentially decoupled. The combination of butterfly coils and / or loop coils so that their apex bends toward the chest wall is a novel structure.

The combination of asymmetric butterfly coils (longitudinal in the anterior-posterior direction with large loops in the rear) is diagonal loops or similarly essentially decoupled when located posterior to the central axis of the butterfly coil in the anteroposterior direction. The coil arrangement is provided so that it is decoupled from the butterfly coil.

The combination of butterfly coils in a fixed central support structure where the left and right coil sets are substantially decoupled by using overlap, capacitive, or inductive decoupling is also a novel construction. Is. All combinations of the coil arrangements using the coils are also novel structures.

The combination of these decoupled coil arrangements as a receive coil, a transmit coil, or a transmit and receive coil is a novel structure. The configuration of these coils for bilateral images is provided by the preferred set below. 1) Essentially decoupled coils (vertical butterfly coil and loop coil), (various transmission line line coil and loop coil), (transmission line line coil and butterfly coil), (multiple loop butterfly coil and loop or transmission line) Movable side coil plate and center coil plate that house the line coil). 2) A fixed sternum support with movable side coil plates and coils provided substantially in the center left and center right directions that are decoupled to each other using a decoupling circuit. 3) A fixed sternum support with side coils provided in a fixed position. 4) Arrangement of 1), 2), or 3) using the front coil. 5) Arrangement of 1), 2), or 3) using the rear coil and opening.

The preferred set combination for bilateral images can also be selected from the following sets. 6) Essentially decoupled coils (vertical butterfly coil and loop coil), (various transmission line line coil and loop coil), (transmission line line coil and butterfly coil), (multiple loop butterfly coil and loop or transmission line) Two movable side coil plates and a central coil plate that house the line coil). 7) A fixed sternum support with a movable side coil plate and a coil provided substantially in the center left or center right direction. 8) A fixed sternum support with side coils provided in a fixed position. All coils are decoupled to each other using a decoupling circuit. 9) Arrangement of 1), 2), or 3) using the front coil. 10) Arrangement of 1), 2), or 3) using the rear coil and opening.

The configuration in which the fixed side coil is attached in a replaceable manner to the fixed sternum coil is a novel concept. This allows 1) to complete the coil circuit of the side or center coil to activate the coil, and 2) the appropriate coil decoupling circuit to minimize the coupling of all the coils in the array. And coils can be connected, and 3) coils can be added to the coil array.

1 MRI 2 MRI holes 3 Mobile station 4 patients 5 Table top coil system 7 Stretcher 8 table top 11 electrical cable 12 MRI connector 18 compression plate 19 compression plate 20 Front structure plate 21 Side structure plate 22 Fixing means 25 RF coil conductor 26 Distributed Capacitor 28 Active blocking circuit 33 RF antenna