Coil assemblies and devices for small animal magnetic resonance elastography

Abstract

The present application relates to the field of magnetic resonance imaging technology, and more particularly to a coil assembly and apparatus for magnetic resonance elastography of small animals. The coil assembly comprises: a first chamber for accommodating a small animal as an examination subject; a radio frequency coil disposed on the outer periphery of the first chamber; and a first hole connected to the first chamber and facing the small animal, for receiving a vibrating member, wherein the vibrating member is inserted into the first chamber through the first hole and contacts the small animal along the direction of the first hole.

Description

Technical Field

[0001] The present application relates to the field of nuclear magnetic resonance technology, and in particular to a coil assembly and device for magnetic resonance elastography of small animals. Background Art

[0002] Magnetic resonance elastography (MRE) is a test that combines magnetic resonance imaging (MRI) with low-frequency vibrations to produce a visualization called an elastogram, which can reveal tissue changes caused by disease. By performing MRE on small animals, such as mice, it is possible to study the development of animal tissues and organs, as well as certain pathological processes.

[0003] See Figure 7 and Figure 8 The coil assembly for performing magnetic resonance elastography on the small animal Ra generally includes a chamber for accommodating the small animal Ra (in the figure, the chamber is a hole 3 with two ends open). ` ), a radio frequency coil (omitted from the figure) for transmitting and / or receiving radio frequency signals is arranged on the outer periphery of the chamber and is supported and positioned by the housing of the assembly. When in use, the small animal Ra as the subject is located in the chamber 3 ` Inside, the vibration member 20 ` Along the vertical direction of chamber 3 ` The direction of the cross section is inserted into chamber 3 ` In other words, insert the chamber 3 along the separation space between the RF coil and the small animal ` inside), and along chamber 3 ` The cross-sectional direction (in Figure 8 The vibration member 20 contacts the small animal and transmits the mechanical vibration to the inspected part of the small animal. ` Insert the coil into the chamber 3 along the space between the RF coil and the small animal Ra. ` and contacts the small animal Ra along another direction crossing (eg, perpendicular to) the insertion direction, so that the chamber 3 for accommodating the small animal Ra ` Sufficient cross-sectional space needs to be reserved for arranging the vibration component, which results in the chamber 3 ` The size, especially the cross-sectional size, of the magnetic resonance imaging apparatus increases the distance between the radio frequency coil for receiving and / or transmitting radio frequency signals and the small animal Ra being examined, which is not conducive to obtaining high-quality magnetic resonance images. Summary of the Invention

[0004] In view of this, the present application provides a coil assembly and device for magnetic resonance elastography of small animals.

[0005] The coil assembly for small animal magnetic resonance elastography proposed in this application includes:

[0006] A first chamber is used to accommodate a small animal to be examined;

[0007] a radio frequency coil, disposed on an outer periphery of the first chamber;

[0008] The first hole is communicated with the first cavity and faces the small animal, and is used to receive a vibration member, wherein the vibration member is inserted into the first cavity through the first hole and contacts the small animal along the direction of the first hole.

[0009] In some possible implementations, the orientation direction of the first hole intersects with the body length direction of the small animal.

[0010] In some possible implementations, the orientation direction of the first hole is perpendicular to the body length direction of the small animal.

[0011] In some possible implementations, the radio frequency coil is disposed around the body length direction.

[0012] In some possible implementations, the radio frequency coil defines a virtual cylindrical surface surrounding the first chamber, and the orientation direction of the first hole corresponds to a radial direction of the virtual cylindrical surface;

[0013] When viewed along the direction of the first holes, all of the first holes fall into the interior of the virtual cylindrical surface.

[0014] In some possible implementations, the following are included:

[0015] A first body, comprising the first cavity, the first hole, and the radio frequency coil, wherein the first cavity is formed as a cavity penetrating along the length of the small animal, and the first hole penetrates from the cavity to the outer surface of the first body;

[0016] The second body is mounted to the second body in a manner that it can be removably inserted into the cavity, and includes a second chamber at least partially located within the first chamber and a second hole that passes through the second chamber to the outer surface of the second body, the second chamber is used to accommodate anesthetic gas and the small animal, the anesthetic gas provides anesthetic support for the small animal, the second hole is aligned with the first hole, and is used to receive the vibration member.

[0017] In some possible implementations, the small animal is fixed in the second chamber.

[0018] In a second aspect, a device for magnetic resonance elastography of small animals is proposed, comprising:

[0019] The coil assembly according to the first aspect;

[0020] The vibration component includes a main body and a vibration portion supported by the main body and capable of vibrating relative to the main body. The vibration portion vibrates when supplied with airflow, and the airflow is supplied to the vibration portion via the main body.

[0021] In some possible implementations, the inner wall surface of the first hole is configured to contact the main body portion over the entire circumference, thereby suppressing the shaking of the main body portion in all radial directions of the first hole.

[0022] In some possible implementations, a bracket is included for supporting the coil assembly and the vibration member, and each of the coil assembly and the body portion of the vibration member is fastened to the bracket in an adjustably positionable manner.

[0023] The coil assembly provided in the present application includes: a first chamber for accommodating a small animal as a subject; a radio frequency coil, arranged on the outer peripheral side of the first chamber; a first hole, connected to the chamber and facing the small animal, for receiving a vibration component, wherein the vibration component is inserted into the first chamber via the first hole and contacts the small animal along the direction of the first hole. That is, the vibration component is no longer inserted into the first chamber along the space separating the radio frequency coil and the small animal. Therefore, the vibration component can well contact the small animal without occupying the cross-sectional space of the first chamber, providing vibration support for the small animal, thereby helping to suppress the enlargement of the cross-sectional size of the chamber, thereby shortening the distance between the radio frequency coil and the small animal, and improving the quality of magnetic resonance imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings described below only relate to some embodiments of the present application, and are not limitations to the present application.

[0025] Figure 1 Schematic diagram of a device for magnetic resonance elastography of small animals provided in an embodiment of the present application.

[0026] Figure 2 yes Figure 1 A schematic diagram of the structure shown with the coil assembly removed.

[0027] Figure 3 yes Figure 1 Schematic diagram of the coil assembly.

[0028] Figure 4 is a schematic diagram of a first body of a coil assembly.

[0029] Figure 5 yes Figure 4 sectional view of .

[0030] Figure 6 yes Figure 1 Cross-sectional view of the vibrating component.

[0031] Figure 7 This is a schematic diagram of a device for magnetic resonance elastography of small animals proposed in the related art.

[0032] Figure 8 yes Figure 7 Cross-sectional view of .

[0033] Description of reference numerals:

[0034] Ra - small animals;

[0035] DR1-first direction, DR2-second direction, DR3-facing direction;

[0036] 10-coil assembly, 11-first body, 12-second body;

[0037] 20, 20'-vibrating member, 30-bracket, 40-first clamping assembly, 50-second clamping assembly;

[0038] 1-chamber;

[0039] 2-First hole;

[0040] 3, 3`-cavity;

[0041] 4-Second hole;

[0042] 5-Guide rail;

[0043] 6-guide groove;

[0044] 7-Body part;

[0045] 8-Vibration unit;

[0046] 9-Tooth hook. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions of the embodiments of the present application will be clearly and completely described below in conjunction with the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the described embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application. It is understood that, in the absence of conflict, some technical means of the various embodiments described herein can be replaced or combined with each other.

[0048] In the description of this application, the terms "first," "second," etc., if used, are used solely to distinguish the objects being described and do not convey any order or technical meaning. Thus, an object defined as "first," "second," etc. may explicitly or implicitly include one or more of such objects. Furthermore, for example, the term "first element" alone does not imply the presence of a "second element," nor does the term "second element" alone imply the presence of a "first element." Furthermore, the terms "a" or "an," and the like, do not denote a limitation on quantity, but rather indicate the presence of at least one, and "plurality" means at least two.

[0049] Figures 1 to 6 The device for magnetic resonance elastography of small animals provided in accordance with an embodiment of the present application is shown, which mainly includes a bracket 30 , a coil assembly 10 and a vibration component 20 .

[0050] The bracket 30 is formed into a frame-like structure, comprising a rectangular base plate and four upright posts extending upward from the four corners of the base plate. Two guide rails 5 extending in a first direction DR1 are fixedly connected to the top ends of two of the upright posts and the top ends of the other two posts, respectively. Furthermore, the upper surface of the base plate has a downwardly recessed guide slot 6 extending in the first direction DR1. The guide slot 6 penetrates the base plate in the first direction DR1, and the width of the guide slot 6 in the second direction DR2 is approximately the same as its length in the first direction, so as to be able to receive the bottom portion of the coil assembly 10. The first and second directions DR1 and DR2 are perpendicular to each other.

[0051] The coil component 10 includes a second body 12 and a first body 11 , and the second body 12 is detachably mounted to the first body 11 .

[0052] The second body 12 has a generally cylindrical shape and contains a generally cylindrical second chamber 1. The second chamber 1 can accommodate small animals (e.g., mice) as subjects and has good sealing properties, thereby being able to contain anesthetic gas and maintain the concentration of the anesthetic gas for a long time, providing anesthesia support for the small animal and preventing the small animal from moving autonomously during the MRI examination. In use, the second chamber 1 can be opened to place the small animal inside, and the second chamber 1 can be opened to allow the small animal to be placed inside. Figure 5 The tooth hook 9 and other components shown in the figure fix the small animal in the second cavity 1. Therefore, the second body 12 can also be called a small animal carrier. In addition, the second body 12 also has a second hole 4 that passes through the second cavity 1 to the outer surface of the second body 12.

[0053] In order to facilitate observation of the small animals in the second chamber 1 , the second body 12 may be formed as a transparent structure. For example, at least a portion of the second body 12 may be formed of transparent high-strength glass.

[0054] The first body 11 includes a housing (not shown) and an RF coil (not shown). The housing of the first body 11 is essentially entirely made of plastic and defines a cavity 3 (an example of a first chamber) extending in a first direction DR1, and a first hole 2 extending from the cavity 3 to the outer surface of the first body 11 and aligned with the second hole 4. The cavity 3 has a circular cross-section, and the second body 12 is removably mounted to the housing of the first body 11 in the cavity 3. Specifically, after securing the small animal within the second cavity 1 of the second body 12 using a component such as a tooth hook 9, the second body 12 is inserted into the cavity 3 of the first body 11, extending longitudinally along the small animal's body length. The second body 12 is then fastened to the housing of the first body 11 using bolts. At this point, the small animal within the second body 12 is also contained within the cavity 3. In other words, the cavity 3, serving as the first chamber, accommodates the small animal by accommodating the second body 12 with the small animal inside.

[0055] The radio frequency coil is installed inside the shell of the first body 11 (i.e., within the thickness space of the shell), and is arranged around the cavity 3 and the length direction (DR1) of the small animal, and therefore, is also arranged around the second cavity 1, and therefore, the radio frequency coil is arranged on the outer peripheral side of the second cavity 1, the cavity 3 serving as the first cavity, and the length direction of the small animal.

[0056] In this embodiment, the radio frequency coil is a receiving coil, which is used to receive magnetic resonance signals from the small animal. In other embodiments, the radio frequency coil is a transmitting coil (for example, an integrated transmitting and receiving coil), which is used to transmit radio frequency signals to the small animal to excite hydrogen nuclei in the small animal's body to generate magnetic resonance signals.

[0057] In some embodiments, the radio frequency coil is an array coil composed of a plurality of coil units, and the coil units are arranged around the entire periphery of the bore 3 .

[0058] In some embodiments, the radio frequency coil comprises a toroidal coil extending around lumen 3 .

[0059] The coil assembly 10 is detachably fixed to the bracket 30, and its fixed position in the first direction DR1 is adjustable, that is, the coil assembly 10 can be positioned at multiple positions along the first direction DR1 relative to the bracket 30. Specifically, the guide groove 6 of the bracket 30 receives the bottom of the first body 11 and can guide the coil assembly 10 to move along the first direction DR1. In use, after the position of the coil assembly 10 relative to the bracket 30 along the first direction DR1 is adjusted to the correct position, the second clamping assembly 50 mounted on the bracket 30 is manually operated to fix the position of the coil assembly 10, that is, the coil assembly 10 is fastened to the bracket 30 by the second clamping assembly 50. The second clamping assembly 50 includes two clamping portions that are arranged opposite to each other in the second direction DR2 and have elongated clamping planes.

[0060] The vibration member 20 can be removably inserted into the first hole 2 and the second hole 4 and contact the small animal (more specifically, the back of the small animal) to drive the small animal, especially the examined tissue of the small animal, to vibrate, thereby realizing magnetic resonance elastography of the small animal.

[0061] In this embodiment, the small animal being examined is secured within the second chamber 1 with its length oriented along the length of the second chamber 1. Both the first hole 2 and the second hole 4 face the small animal and are oriented perpendicularly (e.g., perpendicularly) to the animal's length. The vibrating member 20 contacts the small animal along a direction DR3 that intersects the animal's length. This allows the vibrating member 20 to effectively contact the small animal even without occupying the cross-sectional space of the cavity 3, providing vibration support for the small animal. This helps prevent the cross-sectional dimensions of the cavity 3 (first chamber) from being enlarged, thereby shortening the distance between the RF coil and the small animal and improving the quality of magnetic resonance imaging. Furthermore, the second chamber 1 is formed into an elongated shape that is longer in the animal's length.

[0062] On the other hand, in this embodiment, the first hole 2 is oriented in the direction of separation between the radio frequency coil and the small animal (the radial direction of the cavity 3 ).

[0063] In other embodiments, the second body 12 is omitted, and the small animal being examined is positioned directly within the bore 3, serving as the first chamber, with an anesthesia mask covering the small animal providing anesthesia support. This approach also helps prevent the cross-sectional dimensions of the bore 3 from being enlarged, thereby shortening the distance between the RF coil and the small animal and improving the quality of magnetic resonance imaging. More specifically, the vibrating member 20 comprises a main body 7 and a vibrating portion 8 supported by and capable of vibrating relative to the main body 7. The vibrating portion 8 contacts the small animal along the direction DR3 of the second hole 4 (also the direction DR3 of the first hole 2). The main body 7 is a hollow structure, defining an airflow path. The vibrating portion 8 is a thin film structure mounted on one end of the main body 7. In use, the other end of the main body 7 is connected via an air tube to the output of an air compressor. The air compressor provides a regularly varying airflow to the thin film vibrating portion 8, causing it to vibrate. Specifically, the vibrating portion 8 vibrates due to the varying airflow supplied to it via the main body 7.

[0064] The outer shape of the vibration member 20, particularly the main body 7, has a circular cross-section. Accordingly, when viewed along the orientation direction DR3 (axial direction) of the first and second holes 2 and 4, the first and second holes 2 and 4 are circular, and the diameters of the first and second holes 2 and 4 are substantially equal to the diameter of the vibration member 20. This allows the inner wall surface of the first hole 2 and the inner wall surface of the second hole 4 to contact the main body 7 of the vibration member 20 throughout their entire circumference. Therefore, vibration of the main body 7 can be suppressed in all radial directions of the first hole 2, and in all radial directions of the second hole 4. This suppresses displacement artifacts caused by vibration of the main body 7 during magnetic resonance imaging.

[0065] In this embodiment, the RF coil defines a virtual cylindrical surface surrounding the bore 3 and the second chamber 1. The orientation direction DR3 of the first and second holes 2 and 4 corresponds to the radial direction of this virtual cylindrical surface. Furthermore, when viewed facing the first and second holes 2 and 4, that is, when viewed along the orientation direction DR3 of the first and second holes 2 and 4, both the first and second holes 2 and 4 are completely within this virtual cylindrical surface.

[0066] In order to more firmly stabilize the position of the main body 7 of the vibration member 20 and thus better avoid displacement artifacts, a first clamping assembly 40 supported by the aforementioned two guide rails 5 is configured. The first clamping assembly 40 releasably clamps the main body 7 of the vibration member 20 on the opposite side of the first hole 2 from the second hole 4, thereby fastening the vibration member 20 to the bracket 30, thereby positioning the position of the vibration member 20 relative to the coil assembly 10. The guide rail 5 can guide the first clamping assembly 40 to move along the first direction DR1, and by rotating the tightening screws at both ends of the first clamping assembly 40 along the second direction DR2, the first clamping assembly 40 can be positioned relative to the guide rail 5 at multiple positions along the first direction DR1, thereby adjusting the position of the first clamping assembly 40 relative to the coil assembly 10 to adapt the position of the vibration member 20 to the position of the small animal.

Claims

1. A coil assembly for magnetic resonance elastography of small animals, characterized in that: include: A first chamber is used to accommodate a small animal to be examined; a radio frequency coil, disposed on an outer periphery of the first chamber; The first hole is communicated with the first cavity and faces the small animal, and is used to receive a vibration member, wherein the vibration member is inserted into the first cavity through the first hole and contacts the small animal along the direction of the first hole.

2. The coil assembly according to claim 1, wherein The orientation direction of the first hole intersects with the body length direction of the small animal.

3. The coil assembly according to claim 2, wherein: The orientation direction of the first hole is perpendicular to the body length direction of the small animal.

4. The coil assembly according to claim 2, wherein: The radio frequency coil is arranged around the length of the body.

5. The coil assembly according to claim 1, wherein The RF coil defines a virtual cylindrical surface surrounding the first chamber, and the orientation direction of the first hole corresponds to the radial direction of the virtual cylindrical surface; When viewed along the direction of the first holes, all of the first holes fall into the interior of the virtual cylindrical surface.

6. The coil assembly according to claim 1, wherein The first hole faces a direction that separates the radio frequency coil from the small animal.

7. The coil assembly according to any one of claims 1 to 6, characterized in that: include: A first body, comprising the first cavity, the first hole, and the radio frequency coil, wherein the first cavity is formed as a cavity penetrating along the length of the small animal, and the first hole penetrates from the cavity to the outer surface of the first body; The second body is mounted to the second body in a manner that it can be removably inserted into the cavity, and includes a second chamber at least partially located within the first chamber and a second hole that passes through the second chamber to the outer surface of the second body, the second chamber is used to accommodate anesthetic gas and the small animal, the anesthetic gas provides anesthetic support for the small animal, the second hole is aligned with the first hole, and is used to receive the vibration member.

8. A device for magnetic resonance elastography of small animals, characterized in that: include: The coil assembly according to any one of claims 1 to 7; The vibration component includes a main body and a vibration portion supported by the main body and capable of vibrating relative to the main body. The vibration portion vibrates when supplied with airflow, and the airflow is supplied to the vibration portion via the main body.

9. The device according to claim 8, characterized in that The inner wall surface of the first hole is configured to contact the body portion over the entire circumference, thereby suppressing vibration of the body portion in all radial directions of the first hole.

10. The device according to claim 8, characterized in that A bracket for supporting the coil assembly and the vibration member is included, and each of the coil assembly and the body portion of the vibration member is fastened to the bracket in an adjustably positionable manner.

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