Patent Description:
Typically, an RF coil for imaging parts is embedded in a body (e.g., fixed-array coil) of an MRI and is sized to fit a largest object of interest (OOI) that is intended for imaging. These coils are typically rigid and must be shaped and sized so that they are large enough to accommodate the largest envisioned OOI (e.g., the largest patient). This may result in a fixed-array coil having a large minimum volume. However, when a fixed-array coil with a large minimum volume is used to scan a smaller OOI (e.g., a small patient), it may not fit snugly against the OOI due to its volume. This may result in poor image performance, as it is well established that the best imaging performance may be possible when an RF coil fits snugly around an OOI and has the smallest imaging volume that can accommodate the OOI being scanned.

To solve the problem of bad imaging when a small OOI is imaged, RF coils that can be positioned closer to the OOI were developed. For example, for imaging parts of a body, such as knees, elbows, and the like, one solution is to use RF receive coils that are separate from the body of the MRI. However, these prior systems have significant problems including ease of use and the ability to produce satisfactory images. For example, one prior system for imaging a knee requires the individual coil portions to be fixedly fastened together prior to being positioned around the knee to create a fixed size volume that may be imaged. With this system, where the sizing is not suitable, the coil must be removed and resized to adjust the imaging volume. In another prior system, a coil consisting of a lower part rigidly locked onto a baseplate is provided. In operation, the patient is then placed into position on the lower part and the upper part is placed over the patient and locked onto the lower part in a single fixed position. This solution is hard to utilize since it has been found that it is desirable that the top part of the coil is adjustable to varying heights to accommodate a greater range of patient sizes. Also, in this system during the positioning and locking of the upper part to the lower part, the patient anatomy is not visible and there are risks in squeezing or pinching the patient anatomy between the coil parts or simply not properly positioning the coil in relation to the OOI. Similarly it is desirable that the coil is close to the patient's anatomy for scanning the OOI including a portion of the patient's anatomy. Unfortunately, these prior coils may experience large variations in performance for example due to variations in tuning that result from distortions of receive loops, variations in proximity between these loops, and/or the distance between the loops and the patient's anatomy. Another problem with these coils are mechanical locking features that make the coils more expensive and prone to mechanical failure. In addition, these coils often lack real positioning assist to indicate a preferred coil positioning with relation to the patients anatomy and specific coil positioning features.

<CIT> discloses a device to retrofit a magnetic resonance imaging (MRI) apparatus to physically separate RF imaging coils from any patient movement, thereby eliminating potential coil-displacement related reconstruction effects or artifacts in parallel magnetic resonance imaging. It includes a support member attached to the MRI apparatus, with an RF multi-coil imaging array attached to this support member. The rigid support members are positioned in relation to a patient lying on the MRI table, ensuring the RF multi-coil imaging array is sufficiently distant from the patient to prevent any contact or movement of the coils. The support member is rigid and attachable to the MRI table. Additionally, the rigid support members have an arcuate shape. Alternatively, the support members can be made of a semi-rigid material with an adjustable curvature to accommodate the body wall curvature of the patient being imaged.

Accordingly, embodiments of the system according to the invention may overcome these and other disadvantages of conventional MRI and MRS systems.

The system(s), device(s), method(s), arrangements(s), user interface(s), computer program(s), processes, etc. (hereinafter each of which will be referred to as a system, unless the context indicates otherwise), described herein may address one or more problems in the prior art systems.

In accordance with a first aspect of the invention, there is provided an RF coil apparatus for MR systems as defined in claim <NUM>.

According to an embodiment, the fasteners of the base and the positioner may be corresponding hook-and-loop type fasteners.

In accordance with embodiments of the system according to the invention, at least one of the fasteners of the positioner may comprise a tab suitable for grasping by a user. The positioner may be formed from a sheet of transparent, semi-transparent, or translucent plastic. The positioner may further comprise opposed flanges situated between the opposed ends. The opposed flanges may be configured to align the upper section in a desired position relative to at least one of the positioner and the base. The positioner may be further configured to support the upper section at a desired height. At least a portion of the positioner may be situated between the base and the upper section. The positioner may include at least one landmark for alignment relative to the OOI. The base may further comprise at least one RF coil array for acquiring induced MR signals. A communication link may be configured to couple the base and the upper section.

In accordance with a second aspect of the invention, there is provided a method as defined in claim <NUM>.

The method may further include one or more eete-of coupling a communication link between the base and the upper section and enhancing rigidity of the positioner using the upper section.

The present invention is explained in further detail in the following exemplary embodiments and with reference to the figures, where identical or similar elements are partly indicated by the same or similar reference numerals, and the features of various exemplary embodiments being combinable, provided that the resulting subject-matter falls within the scope of the invention as defined by the claims.

The following are descriptions of illustrative embodiments that when taken in conjunction with the following drawings will demonstrate various aspects of the claimed invention. In the following description, for purposes of explanation rather than limitation, illustrative details are set forth such as architecture, interfaces, techniques, element attributes, etc. However, it will be apparent to those of ordinary skill in the art that other embodiments that depart from these details would still be understood to be within the scope of the appended claims. Moreover, for the purpose of clarity, detailed descriptions of well known devices, circuits, tools, techniques, and methods are omitted so as not to obscure the description of the system according to the invention. It should be expressly understood that the drawings are included for illustrative purposes and do not represent the entire scope of the system according to the invention. In the accompanying drawings, like reference numbers in different drawings may designate similar elements. The term and/or and formatives thereof should be understood to mean that only one or more of the recited elements may need to be suitably present (e.g., only one recited element is present, two of the recited elements may be present, etc., up to all of the recited elements may be present) in a system in accordance with the claims recitation and in accordance with one or more embodiments of the system according to the invention.

For the sake of clarity, embodiments of the system according to the invention will be shown and described with respect to knee-type RF coils (e.g., knee coils). However, it is also envisioned that embodiments of the system according to the invention may include other shapes and/or sizes so that they are compatible with other desired parts of a body such as shoulders, wrists, elbows, necks, etc., without significant modifications.

<FIG> shows a partially cutaway exploded front side view of a portion of an RF coil system <NUM> (hereinafter system <NUM> for the sake of clarity) operating in accordance with embodiments of the system according to the invention. The system <NUM> includes a base <NUM> (e.g., a posterior coil part or posterior housing), a positioner <NUM> and an upper section <NUM> (e.g., an anterior coil part or anterior housing). At least one of the base <NUM>, the positioner <NUM> and the upper section <NUM> may include one or more RF coil arrays which may at least receive induced MR signals. According to the invention, the upper section <NUM> comprises at least one RF coil array.

The received induced MR signals may then be provided to a controller of the system <NUM> which may be part of the base <NUM> and/or upper section <NUM>. It is also envisioned that the RF coil array(s) may include transmit and/or receive type RF coil arrays.

The base <NUM> includes a body <NUM>, an optional RF coil array <NUM>, a support <NUM>, and an attachment mechanism <NUM>. The attachment mechanism <NUM> includes any suitable fasteners to releasably fasten the positioner <NUM> to the base <NUM> in a desired position. For example, the attachment mechanism <NUM> may include a hook-and-loop type fasteners (e.g., Velcro™, etc.) such as fasteners <NUM> situated on opposed sides <NUM> (only one side is shown) of the body <NUM>. Although discrete fasteners <NUM> are shown, it is also envisioned that the fasteners may include a continuous or substantially continuous strip which may extend across each side and/or from side to side of the opposed sides <NUM>. For example, it is also envisioned that in embodiments of the system according to the invention, the fasteners may <NUM> may continuously or substantially continuously extend about the body <NUM>. Further, it is envisioned that a single hook-and-loop type fastener may extend about the opposed sides <NUM> of the body <NUM>. Further, although the hook-and-loop fasteners are illustrated as strips, it is envisioned that they may assume other shapes such as square, round, rectangular, etc. The fasteners <NUM> may be attached to the body <NUM> using any suitable method such as adhesives, mechanical fastening, etc., that are suitable for the material utilized in forming the body <NUM>.

The body <NUM> may define one or more cavities such as at least one cavity <NUM> in which the RF coil array <NUM> and/or a controller (e.g., one or more processors) may be situated. In accordance with further embodiments of the system according to the invention, the RF coil array <NUM> and/or a controller (e.g., one or more processors) may be formed within the body <NUM>.

In accordance with further embodiments of the system according to the invention, the support <NUM> may be anatomically shaped to support a desired OOI. For example, the support <NUM> may include an arc as shown to support a knee when the system <NUM> is configured to function as a knee coil. The support <NUM> may be padded to enhance patient comfort, as desired. However, it is also envisioned that yet other embodiments of the system according to the invention may include a support having other shapes and/or sizes to anatomically support other desired OOIs such as shoulders, elbows, necks, ankles, etc. as may be desired with minimal modification.

In accordance with embodiments of the system according to the invention, the positioner <NUM> includes a body <NUM> and an optional RF coil array. The positioner <NUM> has opposed major surfaces <NUM>, opposed edges <NUM>, and opposed ends <NUM>. The body <NUM> may be formed from a thin shell formed from one or more materials such as a plastic, methyl methacrylate, vinyl, poly-vinyl, and/or other material(s) that may be suitably formed and applied.

In accordance with embodiments of the system according to the invention, the positioner <NUM> may be formed as a translucent and/or semi-translucent shell. In these embodiments, the OOI is visible or partially visible through the positioner <NUM> which assists in proper positioning of the positioner <NUM> to assist in maximizing an imaging response received by the knee coil. The positioner <NUM> may include landmarks such as graphics which a user such as a clinician may use to properly align the positioner <NUM> with regard to the OOI and/or other portions of the system. Further discussion of the landmarks is made with regard to <FIG> which are intended to be optionally applicable in accordance with each of the embodiments shown in the figures.

In accordance with embodiments of the system according to the invention, the translucent plastic shell may be gradually folded or otherwise bent depending on the OOI, for example with regard to a knee, so as to form a "C" or "U" shape when attached to the base <NUM> as illustratively described and shown herein.

In accordance with the invention, the positioner <NUM> includes an attachment mechanism <NUM> which is configured to complementary couple to the attachment mechanism <NUM> of the base <NUM>. For example, the attachment mechanism <NUM> may include one or more hook-and-loop type fasteners such as fasteners <NUM> which may releasably couple to corresponding fasteners <NUM> of the base <NUM> so as to couple the positioner <NUM> to the base <NUM> in a desired position. The fasteners <NUM> may include tabs <NUM> suitable for grasping by a user to decouple a corresponding fastener <NUM> from the corresponding fastener <NUM> of the base <NUM>. The tabs <NUM> may extend past a periphery of the body <NUM> so that the tabs <NUM> may be easily grasped. However, it is also envisioned that the tabs may be formed integrally with the body and the fasteners.

The fasteners <NUM> may be located adjacent to a corresponding end of the opposed ends <NUM>. The positioner <NUM> may be coupled to the base <NUM> such that its position relative to a longitudinal axis (La) of the base <NUM> and may be adjustable described. Similarly, the positioner <NUM> may be coupled to the base <NUM> such that its height (h) relative to the base <NUM> may vary as described. For the sake of clarity, it may be assumed that the longitudinal axis (La) may be aligned with a z axis and the height (h) may be adjusted along a y axis such that a change in height may correspond with a change in the y axis). For the sake of clarity, it should be appreciated that the x, y, and z axes discussed herein regarding the system <NUM> may correspond with x, y, and z axes, respectively, of an MRI in which embodiments of the system according to the invention may be used.

In accordance with the invention, the positioner <NUM> guides or otherwise assists in aligning the upper section <NUM> relative to the base <NUM> with respect to height and/or longitudinal location so as to position the upper section <NUM> in a desired location relative to the base <NUM>.

The flanges <NUM> is formed from a flexible material as suitably applied and may be located adjacent to, or close by, a corresponding one of the opposed edges <NUM> of the positioner <NUM>. However, in yet other embodiments, it is envisioned that the flanges <NUM> may be located between the opposed edges <NUM>. The flanges <NUM> may be formed integrally with, or separately from, the body <NUM> of the positioner <NUM> from the same of different materials. For example, one or more of the flanges <NUM> may be formed from a flexible rubber or plastic which may be coupled to the body <NUM> which may be formed from, for example, a clear plastic such as acrylic or polycarbonate. However, in yet other embodiments, the body <NUM> may be molded to integrally form one or more of the flanges <NUM>, as may be desired.

It is envisioned that one or more portions of the positioner <NUM> such as the body <NUM> may be formed from any suitable material such as a plastic, etc. For example, the positioner <NUM> may be formed from a plastic such as an acrylic (e.g., Plexiglas™, etc.), a polycarbonate, etc. The plastic may include a thermoplastic, as desired. Moreover, the positioner <NUM> may be molded into a desired shape for a given OOI or may be flat and may be folded or bent by a user during use. According to the invention, the positioner is flexible.

In accordance with further embodiments of the system according to the invention, the positioner <NUM> may be disposable. Further, the positioner <NUM> may be shaped, sized, and/or landmarked (as described herein) in accordance with a desired use or application(s) intended for the positioner <NUM>. When folded or otherwise bent, the body <NUM> gains rigidity so as to be capable of supporting the upper section <NUM> during use, as configured. Accordingly, the body <NUM> may be formed from a thin sheet of material having a rigidity that may be enhanced when arched (e.g. folded or otherwise bent) during use. In accordance with embodiments of the system according to the invention, a biasing member (e.g., a semi-coiled wire spring) may be coupled to the positioner <NUM> to provide a biasing force to hold the positioner <NUM> in a desired shape, if so configured. The biasing member may, for example, be situated within a corresponding flange <NUM>.

The upper section <NUM> includes a body <NUM> and an RF coil array <NUM> coupled to the body <NUM>. The body <NUM> may include bottom ends <NUM>, opposed edges <NUM>, and an interior wall <NUM> defining a central chamber <NUM>. The central chamber <NUM> may define at least part of the imaging volume in which the OOI may be situated for scanning. The upper section <NUM> contacts the positioner <NUM> such that the height and/or longitudinal position of the upper section <NUM> relative to the base <NUM> is determined by a position and/or orientation of the positioner <NUM> relative to the base <NUM>.

In accordance with embodiments of the system according to the invention, the upper section <NUM> may be situated between the flanges <NUM> of the positioner <NUM>. However, it is also envisioned that the positioner <NUM> and/or the upper section <NUM> may include a guide track (e.g., a rail and/or slot) which may control the position of the upper section <NUM> relative to the positioner <NUM>. Although a single side is shown, the opposite side of the system <NUM> may be similar to the side shown or altered depending on an intended use.

<FIG> shows a partially cutaway exploded end view of a portion of the RF coil system <NUM> in accordance with embodiments of the system according to the invention. The fasteners <NUM> may be coupled to one of the major surfaces <NUM> of the body <NUM> such as an interior major surface 131i of the major surfaces <NUM> using any suitable method such as adhesives, etc., as described. The tabs <NUM> of the fasteners <NUM> may extend beyond an outer periphery of the body <NUM> of the positioner <NUM>. In accordance with embodiments of the system according to the invention, the positioner <NUM> may be formed of a translucent or semi-translucent plastic material. In these embodiments, the positioner <NUM> is configured and/or otherwise formed to accommodate the OOI, such as to surround a knee (e.g., on three sides), when the positioner <NUM> is formed such as a portion of a knee coil. Although a single end is shown, the opposite end of the system <NUM> may be similar or different as desired and/or based on a given application.

<FIG> shows a partially cutaway end view of a portion of the RF coil system <NUM> in accordance with embodiments of the system according to the invention. The system <NUM> is shown in a position suitable for performing a scanning operation in which the base <NUM> and/or the upper section <NUM> may define at least part of the imaging volume (IV) in which an OOI (not shown for the sake of clarity) such as a knee and/or other body part of a patient may be placed for scanning. The positioner <NUM> may be situated adjacent to the OOI such that it may be between at least a portion of the OOI and the interior wall <NUM> of the body <NUM>.

Further, in embodiments when provided, RF coil arrays within the base <NUM>, the positioner <NUM> and/or the upper section <NUM> may be in substantially perpendicular arrangement relative to each other or otherwise fixedly aligned relative to each other during positioning. For example, in accordance with embodiments of the system according to the invention, as a result of complementary structures on one or more of the base <NUM>, the positioner <NUM> and/or the upper section <NUM>, the position of the RF coils arrays are provided in a fixed relation to each other. In this way, problems in aligning the one or more coils to each other and/or the OOI that exist in prior systems are alleviated.

<FIG> shows a bottom view of a portion of the RF coil system <NUM> similar to that shown in <FIG> in accordance with embodiments of the system according to the invention. The body <NUM> of the base <NUM> may include a bottom cover <NUM>. The bottom cover <NUM> may seal the at least one cavity (e.g., see, <NUM>, <FIG>) of the base <NUM>. The bottom cover <NUM> may include mounting pads as desired for example to prevent, and/or reduce undesirable movement during use, assist in positioning the OOI, and/or otherwise aid in positioning and/or comfort of the patient.

<FIG> shows a top view of a portion of a portion of the RF coil system <NUM> in accordance with embodiments of the system according to the invention including a positioner 304A in a flattened position in accordance with embodiments of the system according to the invention. The positioner <NUM> may be similar to the positioner <NUM> and similar numerals may have been used to denote similar portions thereof.

In accordance with embodiments of the system according to the invention, the positioner <NUM> may include landmarks such as graphics <NUM> which a user such as a clinician may use to properly align the positioner <NUM> with regard to the OOI and/or other portions of the system. The landmarks, may include any suitable graphics, text, etching, notches, tabs, slots, etc., which may guide a user so that the user may locate the positioner <NUM> relative to an OOI and/or portions of the system. The landmarks may further illustrate to a user a direction in which the positioner <NUM> may be bent for use, wherein the positioner <NUM> is flexible in accordance with the invention. The landmarks may include graphics such as a rule <NUM> and/or other graphics that a user may use to align the positioner <NUM> relative to the OOI and/or the base <NUM> and/or portions thereof. Further, a user may mark the positioner <NUM> using a marker (erasable or non-erasable) as may be desired.

The landmarks may further include instructions for desired uses (e.g., "for a knee scan, align knee positioning landmarks with corresponding portions of the knee," "for a shoulder scan, align shoulder positioning landmarks with corresponding portions of the shoulder," for an arm scan, align arm positioning landmarks with corresponding portions of the arm," etc.). The positioner <NUM> is flexible such that it may be flexibly formed around the OOI during setup. As readily appreciated, the shape of the positioner <NUM> still complements the shape that of the base and the upper section as described.

In accordance with embodiments of the system according to the invention, the positioner <NUM> may be folded, bent, rolled, etc., each term and other variations used herein for example, however should be understood to encompass other configurations of the system according to the invention, wherein the positioner is otherwise formed to the OOI at the time that the positioner is placed around the OOI (e.g., formed along line <NUM> as described herein). In one or more of these embodiments, the positioner <NUM> may be stored in a flattened orientation as desired and shown. In an embodiment wherein the positioner <NUM> is rollable, the positioner <NUM> may be stored in many shapes as desired. Other characteristics of a positioner such as the positioner <NUM> are descried herein with reference to further figures.

<FIG> shows a top view of a portion of a portion of the RF coil system <NUM> including a positioner 304B in a flattened position in accordance with embodiments of the system according to the invention. The positioner 304B may be similar to the positioner <NUM> and similar numerals may have been used to denote similar portions thereof. However, the positioner 304B may include notches <NUM> cut into a body <NUM> of the positioner 304B on either side of fasteners <NUM> that are attached to the body <NUM>. Further, flanges <NUM> may be located slightly away from adjacent ends <NUM>. The notches <NUM> may include any suitable cut which may separate the body <NUM> along the cut. Further, the notches <NUM> may interrupt a periphery of opposed ends <NUM>.

<FIG> shows a detailed cross-section view of a portion of a positioner and upper section of an RF coil system <NUM> such as taken along lines <NUM>-<NUM> of <FIG> in accordance with embodiments of the system according to the invention. In the illustrative embodiment, the positioner <NUM> and the upper section <NUM> of the RF coil system <NUM> is shown. In accordance with embodiments of the system according to the invention, longitudinal alignment (e.g., along the La) of the upper section <NUM> relative to the base (e.g., <NUM>) may be controlled by the flanges <NUM> of the positioner <NUM> which may contact opposed edges <NUM> so as to guide the upper section <NUM> into a desired position (alignment) relative to the base. Further, height (h) of the upper section <NUM> relative to the base <NUM> may be controlled by the interior wall <NUM> of the upper section <NUM> contacting an adjacent major surface <NUM> of the positioner <NUM>.

<FIG> shows a side view of an RF coil system <NUM> including a range of motion of a positioner <NUM> relative to a base <NUM> in accordance with embodiments of the system according to the invention. The positioner <NUM> and the base may be similar to the positioner <NUM> and the base <NUM>, respectively. An OOI such as a knee <NUM> of a patient <NUM> is shown for the sake of clarity. Lateral position and height of the of the positioner <NUM> may varied relative to the base <NUM> as illustrated by ΔL (e.g., change along the longitudinal axis) and Δh (e.g., change along the y axis), respectively. In accordance with embodiments of the system according to the invention, this may provide for desired alignment of an upper cover relative to the base. Further, in accordance with embodiments of the system according to the invention, as described the positioner may change height from the base, for example to accommodate different patient sizes (e.g., to accommodate an adult and a child).

<FIG> shows a detailed cross-section view of an RF coil system <NUM> including a portion of a positioner <NUM> and an upper section <NUM> in accordance with embodiments of the system according to the invention. The positioner <NUM> and the upper section <NUM> may be similar to the positioner <NUM> and the upper section <NUM>, respectively. However, the upper section <NUM> may include a flange <NUM> located at each opposed edge <NUM> (only one of which is shown for the sake of clarity) and the positioner <NUM> may include opposed edges <NUM> (only one of which is shown for the sake of clarity) which may lack flanges. The flange <NUM> may contact an adjacent one of the opposed edges <NUM> to guide the upper section <NUM> into alignment during use. In accordance with yet other embodiments, other types of guides may be suitably utilized to position upper section relative to the positioner and/or the positioner relative to the base.

<FIG> shows an exploded perspective end view of a portion of an RF coil system <NUM> (hereinafter system <NUM> for the sake of clarity) operating in accordance with embodiments of the system according to the invention. The system <NUM> may be similar to the system <NUM> and includes a base <NUM>, a positioner <NUM>, and an upper section <NUM> that may be similar to the base <NUM>, the positioner <NUM>, and the upper section <NUM>, respectively, of the system <NUM>. In accordance with embodiments of the system according to the invention, the base <NUM> may include a distal end <NUM> and a communication link such as a wireless link <NUM> for external communication (e.g., with an MRI control system, etc.).

The positioner <NUM> includes a body <NUM> and optional flanges <NUM>, the latter of which may act as guides to align the upper section <NUM> relative to the positioner <NUM> and/or the base <NUM>. The positioner <NUM> includes a fastener system such as a hook-and-loop type fasteners <NUM> which are configured to couple to corresponding hook-and-loop fasteners <NUM> of the base <NUM>. The fasteners may be shaped, sized, and/or positioned relative to the base <NUM> and/or the positioner <NUM> so that a desired change along a longitudinal axis and a desired change in height of the positioner <NUM> relative to the base <NUM> may be accommodated and secured.

A process of setting up the system <NUM> to perform a scan of a knee of a patient is described with reference to <FIG>, and <FIG> wherein: <FIG> shows a perspective font side view of a portion of the RF coil system <NUM> in which the positioner <NUM> is being positioned about a knee <NUM> of a patient <NUM> in accordance with embodiments of the system according to the invention; <FIG> shows a perspective rear side view of a portion of the RF coil system <NUM> in which the positioner <NUM> is positioned about the knee <NUM> of the patient <NUM> in accordance with embodiments of the system according to the invention; <FIG> shows a perspective rear end view of a portion of the RF coil system <NUM> in which the upper section <NUM> is being positioned over the positioner <NUM> and the knee <NUM> of the patient <NUM> in accordance with embodiments of the system according to the invention; <FIG> shows a perspective rear end view of a portion of the RF coil system <NUM> in which the upper section <NUM> is positioned over the positioner <NUM> and the knee <NUM> of the patient <NUM> in accordance with embodiments of the system according to the invention; and <FIG> shows a perspective front side view of a portion of the RF coil system <NUM> in which the positioner <NUM> is being removed from the base <NUM> in accordance with embodiments of the system according to the invention.

With reference to <FIG>, the positioner <NUM> may be placed about the base <NUM> and an OOI such as a knee <NUM> of a patient <NUM>. The positioner <NUM> may be aligned relative to the knee <NUM> using landmarks <NUM> such as crosshairs, etc. Once aligned, the hook-and-loop fasteners <NUM> of the positioner <NUM> may be situated about the base <NUM> and the OOI so as to align the positioner <NUM> in a desired position relative to the base <NUM>. In accordance with embodiments of the system according to the invention, hook-and-loop fasteners <NUM> of the positioner <NUM> may be secured to corresponding hook-and-loop fasteners <NUM> of the base <NUM> so as to secure the positioner <NUM> to the base <NUM> in a desired position. When aligned, the positioner <NUM> may snugly surround the OOI as may be desired.

With reference to <FIG>, the user is shown engaging hook-and-loop fasteners <NUM> and <NUM> to each other so as to secure the positioner <NUM> relative to the base <NUM>. In accordance with embodiments of the system according to the invention, the wired link <NUM> may extend from the distal end <NUM> and may be configured for wireless coupling to an external communication system, such as wireless communication system, as desired.

With reference to <FIG>, once the positioner <NUM> is aligned and secured to the base <NUM>, the upper section <NUM> may be slid over the positioner <NUM>. In accordance with embodiments of the system according to the invention, the upper section <NUM> may be guided by an exterior surface of the body <NUM>. Further, the upper section <NUM> may be guided by the flanges <NUM> which may engage corresponding opposed edges <NUM> of the upper section <NUM>. Accordingly, the positioner <NUM> guides the upper section <NUM> into a desired position relative to the base <NUM>. The upper section <NUM> may include an interior wall <NUM> defining a central chamber <NUM>. The upper section <NUM> may include a wired and/or wireless (e.g., radio frequency, fiber optic, etc.) link <NUM> which may be coupled to an external communication port or to a port on the base <NUM>, as desired. In accordance with embodiments of the system according to the invention, the base <NUM> may operate to couple signals from the link <NUM> to the link <NUM> so as to form a piggy back connection and/or otherwise couple a connection from the base <NUM> as desired.

With reference to <FIG>, after sliding the upper section <NUM> over the positioner <NUM>, the upper section <NUM> may be aligned in a desired position for scanning. The positioner <NUM> may support the interior wall <NUM> of the upper section <NUM> so as to control height and/or orientation of the upper section <NUM> in relation to the base <NUM>. The opposed edges <NUM> of the upper section <NUM> may be situated between the flanges <NUM> (only one of which is shown).

In accordance with the invention, the arched shape to the positioner <NUM> enhances rigidity of the positioner. Further, as the shape of the interior wall <NUM> of the upper section <NUM> corresponds with the arched shape of the interior wall <NUM>, when in contact it further enhances the rigidity of the positioner <NUM>. Further, in accordance with embodiments of the system according to the invention, the interior wall <NUM> may engage the hook-and-loop fasteners <NUM> and <NUM> of the positioner <NUM> and the base <NUM>, respectively, so as to maintain the coupling between these fasteners.

With reference to <FIG>, in accordance with embodiments of the system according to the invention, to remove the system <NUM> from the patient, the upper section <NUM> may be removed from the positioner <NUM>. For example, corresponding hook-and-loop fasteners <NUM> and <NUM> may be decoupled from each other. The positioner <NUM> may include slots <NUM> which may be similar to the slots <NUM> shown in <FIG>. These slots <NUM> may define tabs <NUM> suitable for grasping by a user to decouple corresponding hook-and-loop fasteners <NUM> and <NUM> each other. Further, a body <NUM> of the positioner <NUM> may provide a biasing force to bias the hook-and-loop fasters <NUM> away from the body <NUM> so as to avoid unintentional attachment between the hook-and-loop fasters <NUM> of the positioner <NUM> and the hook-and-loop fasters <NUM> of the body <NUM> during installation.

<FIG> shows a partially cutaway perspective top end view of an RF coil system <NUM> (hereinafter system <NUM> for the sake of clarity) operating in accordance with embodiments of the system according to the invention. The system <NUM> may be similar to one or more of the other systems and includes a base <NUM>, a positioner, and an upper section <NUM>. The system <NUM> is shown in a position suitable for performing a scanning operation. Accordingly, the base <NUM> together with the positioner and/or the upper section <NUM> may define at least part of the imaging volume (IV) in which an OOI (not shown for the sake of clarity) may be placed for scanning. In accordance with embodiments of the system according to the invention, a link <NUM> may be coupled to an external system controller to enable communication between the external system controller (e.g., an MRI system controller) and the RF coil system <NUM>. Accordingly, image information in any suitable format (e.g., raw, digitized, reconstructed, etc.) may be transmitted to the external system controller for further processing. Further, operating commands and/or instructions may be received from the external system controller. The base <NUM> may be piggy backed to the upper section <NUM> via a link <NUM> (such as a wired link) so as to enable communication between the base <NUM> and the upper section <NUM> and therefore the external system controller. More particularly, the link <NUM> may include a coupler <NUM> which may couple to the upper section <NUM> using any suitable method such as via a port <NUM>.

In accordance with some embodiments, the upper section may be coupled to the base, positioner and/or to the external system controller to enable communication using any suitable wired and/or wireless coupling method. Further, it is envisioned that the upper section may be physically coupled to the base using for example a sliding-type coupling or otherwise as desired.

In accordance with embodiments of the system according to the invention, the system may be shaped and sized such that alignment of the base and the upper section may be performed by fixing the upper section at a height which would allow the smallest knee envisioned to be precisely imaged when a bottom end (e.g., see, <NUM>) of the upper section hits a table surface and then permit the upper section to otherwise rest on the positioner. The system may further include padding which may be integrated with the base, positioner and/or upper section so as to provide comfort to a patient and/or absorb some weight of the RF coil array of the system while providing a small imaging volume. In accordance with embodiments, it is envisioned that the base and the positioner may provide for a larger OOI through adjustment of the positioner over the OOI and adjustment of the base.

A process of setting up a system in accordance with embodiments of the system according to the invention to perform a scan of a knee of a patient is described with reference to <FIG> utilizing a flexible positioner, wherein <FIG> shows a perspective top front side view of a portion of an RF coil system <NUM> in which a positioner <NUM> is being prepared to be positioned about a knee <NUM> of a patient <NUM> in accordance with embodiments of the system according to the invention; <FIG> shows a perspective top front side view of a portion of the RF coil system <NUM> in which the positioner <NUM> is initially positioned about the knee <NUM> of the patient <NUM> in accordance with embodiments of the system according to the invention; <FIG> shows a perspective top front side view of a portion of the RF coil system <NUM> in which the positioner <NUM> is positioned about the knee <NUM> of the patient <NUM> in accordance with embodiments of the system according to the invention; and <FIG> shows a perspective top front side view of a portion of the RF coil system <NUM> in which an upper section <NUM> is situated over the positioner <NUM> in accordance with embodiments of the system according to the invention.

Referring to <FIG>, the positioner <NUM> is similar to the positioner <NUM>. However, in accordance with embodiments of the system according to the invention, the positioner <NUM> may include a continuous hook-and-loop fastener <NUM> portion (e.g., a loop portion of a hook and fastener system) at each of opposed ends <NUM> of the positioner <NUM>. Further, the base <NUM> may include a plurality of hook-and-loop fastener <NUM> portions (e.g., hook portions of a hook and fastener system) on opposed front and rear sides thereof.

In use, an OOI such as a knee <NUM> of a patent <NUM> is placed over the base <NUM> and the positioner <NUM> is wrapped about the OOI (e.g., the knee <NUM>) and thereafter attached to the base <NUM> as illustrated in <FIG> and <FIG>. Thereafter, an upper portion <NUM> is placed over the positioner <NUM> as shown in <FIG> such that it is guided and supported by the positioner <NUM> via the base <NUM> depending upon height settings. The arched shape of the positioner <NUM> enhances rigidity of the flexible positioner <NUM> so that it supports the upper portion <NUM>. As appreciated, though the positioner is flexible in accordance with the invention, it may be formed somewhat as a sheet. In this way, as the positioner is formed around a length of the OOI, the rigidity of the positioner in a plane perpendicular to the length of the OOI is greatly increased as compared to when the positioner is laid flat. In this way, problems with prior system are alleviated in that the weight of the coil need not be supported by the knee and is supported or somewhat supported by the positioner. In accordance with embodiments of the system according to the invention, the system <NUM> may then be ready for MR acquisition.

Accordingly, embodiments of the system according to the invention provide a positioner which supports an anterior (i.e. upper portion) RF receiver coil array over a desired OOI (e.g., anatomy of a patient) for scanning without placing pressure or weight on the patient. An attachment mechanism may provide for the adjustment of the positioner relative to a posterior (e.g., base) portion that may include an RF receiver coil. The positioner may be transparent so that a user such as a clinician may easily and accurately determine how to place the positioner relative to the OOI for scanning so that it may be aligned relative to the OOI. The positioner may be formed from a plastic sheet and, as such, may be extremely light and inexpensive so it can be easily replaced. The upper portion which may weigh considerably more than the positioner may be positioned after the positioner is aligned and attached to the base thereby simplifying a setup process. In accordance with embodiments, the positioner may also cover the patient surface side of the RF coil array of the upper portion, thus cleaning the surface side of the RF coil array of the upper portion may be simplified and less abusive as it need not be in contact with the patient at any time. Further, as the positioner in accordance with embodiments may not include any electronics, it can be easily cleaned or replaced. In accordance with embodiments of the system according to the invention, no adjustable joints need be utilized so setup is simplified and dangers of pinching the OOI may be eliminated.

Thus embodiments of the system according to the invention may provide a flexible, anatomically shaped (coil) positioner formed from a thin, translucent, plastic shell having hook-and-loop fasteners (e.g., Velcro™ pads) adhered in desired locations to allow attachment to the opposing hook-and-loop fasteners adhered to posterior RF receiver coil housing. The hook-and-loop fasteners allow for adjustability in aligning and positioning of the (coil) positioner to make sure the anterior portion including a coil may be aligned properly over a desired OOI (e.g., desired patient anatomy) and in a position to keep pressure and weight off of the patient when the anterior portion is placed onto the positioner. The positioner and hook-and-loop fasteners may be further secured to a posterior portion (e.g., base) by a rigid housing (e.g., body) of the anterior portion as it is placed under the OOI.

<FIG> shows a portion of a system <NUM> in accordance with embodiments of the system outside the scope of the invention as defined by the claims. For example, a portion of the system may include a processor <NUM> (e.g., a controller) operationally coupled to a memory <NUM>, a user interface (UI) including a rendering device such as a display <NUM>, sensors <NUM>, an RF portion <NUM>, magnetic coils <NUM>, and a user input device <NUM>. The memory <NUM> may be any type of device for storing application data as well as other data related to the described operation. The application data and other data are received by the processor <NUM> for configuring (e.g., programming) the processor <NUM> to perform operation acts in accordance with the system. The processor <NUM> so configured becomes a special purpose machine particularly suited for performing in accordance with embodiments of the system.

The operation acts may include configuring an MRI system by, for example, controlling the magnetic coils <NUM>, and/or the RF portion <NUM> in accordance with system settings. An optional location mechanism may control a physical location (e.g., in x, y, and z axes) of a patient and/or the RF portion <NUM>, as desired. The RF portion <NUM> may be controlled by the processor <NUM> to control RF transducers such as RF transmission coils and RF reception coils, and RF states (modes) such as tune/detune and synchronization states. The RF portion <NUM> may include wired- and/or wireless-type RF portions which may be local and/or remote from each other. In accordance with embodiments, the RF portion <NUM> may include a wireless receive-type RF coil such as provided in one or more of a base, positioner and/or top portion. The magnetic coils <NUM> may include main magnetic coils, gradient coils (GR) (e.g., x-, y-, and z-gradient coils), optional gradient shimming coils, and may be controlled to emit a main magnetic field (B<NUM>) and/or gradient fields in a desired direction and/or strength (e.g., Gx, Gy, and Gz). The processor <NUM> may control one or more power supplies to provide power to the magnetic coils <NUM> so that a desired magnetic field is emitted at a desired time. The RF portion <NUM> may be controlled to transmit RF pulses and to receive induced MR signals (e.g., echo information). A processor or portion thereof operating as a reconstructor may process received signals such as the induced MR signals and transform these signals (e.g., using one or more reconstruction techniques of embodiments of the system) into content which may include image information (e.g., still or video images (e.g., video information)), data, and/or graphs (e.g., spectrographic information) that may be rendered on, for example, a UI of the system such as on the display <NUM>, a speaker, etc. Further, the content may then be stored in a memory of the system such as the memory <NUM> for later use. Thus, operation acts may include requesting, providing, and/or rendering of content such as, for example, reconstructed image information obtained from the induced MR information. The processor <NUM> may render the content such as video information on a UI of the system such as a display of the system.

The user input <NUM> may include a keyboard, a mouse, a trackball, or other device, such as a touch-sensitive display, which may be stand alone or part of a system, such as part of a personal computer, a personal digital assistant (PDA), a mobile phone (e.g., a smart phone), a monitor, a smart or dumb terminal or other device for communicating with the processor <NUM> via any operable link such as a wired and/or wireless communication link. The user input device <NUM> may be operable for interacting with the processor <NUM> including enabling interaction within a UI as described herein. Clearly the processor <NUM>, the memory <NUM>, display <NUM>, and/or user input device <NUM> may all or partly be a portion of a computer system or other device such as a client and/or server.

Accordingly, embodiments of the system according to the invention may provide RF coil arrays such as a knee coil array having a body including first, second and third parts including a base, a positioner and an upper section, respectively, one or more of which may include an RF coil array having coil elements. The positioner may be formed as a thin sheet and may couple to the base so as to assist in positioning the upper section. In accordance with embodiments of the system according to the invention, the positioner may be a disposable single-use positioner or may be reusable as desired. As an added advantage, when two or more of the base, the positioner and the upper section include an RF coil array, the coil elements in these RF coil arrays may be substantially isolated from the coil elements in the other RF coil array. The arrangement of the RF coil arrays provides for a wide range of patient sizes while delivering near optimal performance when performing MR acquisition.

Further variations of the system according to the invention would readily occur to a person of ordinary skill in the art and are encompassed by the following claims.

Finally, the above-discussion is intended to be merely illustrative of the system according to the invention and should not be construed as limiting the appended claims to any particular embodiment or group of embodiments. Thus, while the system according to the invention has been described with reference to exemplary embodiments, it should also be appreciated that numerous modifications and alternative embodiments may be devised by those having ordinary skill in the art without departing from the broader and intended scope of the invention as set forth in the claims that follow. Accordingly, the specification and drawings are to be regarded in an illustrative manner and are not intended to limit the scope of the appended claims.

Claim 1:
A radio-frequency, RF, coil apparatus for magnetic resonance, MR, systems (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>), the RF coil comprising:
a base (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) having opposed sides (<NUM>), a surface (<NUM>) to support an object of interest, OOI, for scanning, and fasteners (<NUM>) situated at the opposed sides;
a positioner (<NUM>, 304A, 304B, <NUM>, <NUM>, <NUM>, <NUM>) configured to be releasably attached to the base and having a body (<NUM>) extending between opposed ends and fasteners (<NUM>) situated at the opposed ends of the body, wherein the fasteners of the positioner are configured to couple to corresponding fasteners of the base and the body is configured to (i) form an arch between its opposed ends, thereby enhancing the positioner's rigidity and to (ii) extend along a longitudinal axis (LA) of the RF coil apparatus,
an upper section (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) having at least one RF coil array (<NUM>) for acquiring induced MR signals, the upper section configured to be positioned over the positioner, wherein the positioner is configured to support, when in operation, the upper section without placing pressure or weight on the OOI by guiding and supporting the upper section via the base, characterised in that the positioner is flexible, the positioner is formed around a length of the OOI along the longitudinal axis, and the rigidity of the positioner in a plane perpendicular to the length of the OOI along the longitudinal axis is increased compared to when the positioner is laid flat.