Magnetic Resonance Breast Support

Abstract

Disclosed herein is a medical instrument (100, 200, 300, 400, 500, 600, 900) comprising a subject support (102) configured for supporting a subject (110) in a Fowler's position during a magnetic resonance imaging examination. The subject support comprises a leg support region (104) configured for supporting a leg region of the subject horizontally. The subject support further comprises a thoracic support (106) configured for supporting an upper body region of the subject. The subject support is configured such that the thoracic support is inclined (108) with respect to the leg support region to hold the subject in the Fowler's position. The medical instrument further comprises a breast support (114). The breast support comprises a planar support surface (116) configured for supporting breasts of the subject. The breast support is connected to the subject support. The support surface is configured for being horizontal during the magnetic resonance imaging examination.

Claims

1. A medical instrument comprising a subject support configured for supporting a subject in a Fowler's position during a magnetic resonance imaging examination, wherein the subject support comprises a leg support region configured for supporting a leg region of the subject horizontally during the magnetic resonance imaging examination, wherein the subject support further comprises a thoracic support configured for supporting an upper body region of the subject, wherein subject support is configured such that the thoracic support is inclined with respect to the leg support region to hold the subject in the Fowler's position during the magnetic resonance imaging examination, wherein the medical instrument further comprises a breast support, wherein the breast support comprises a planar support surface configured for supporting breasts of the subject, wherein the breast support is connected to the subject support, wherein the planar support surface is configured for being horizontal during the magnetic resonance imaging examination.

2. The medical instrument of claim 1, wherein the thoracic support is inclined with respect to the leg support region between 10 degrees and 40 degrees, preferably between 15 degrees and 30 degrees.

3. The medical instrument of claim 2, wherein the breast support comprises two edge supports each connected to opposite edges of the thoracic support, wherein the tow edge supports are preferably arm rests, wherein the planar support surface is supported by and is in between the two edge supports, wherein the planar support surface is operable for sliding horizontally between the two edge supports to adjust support of the breasts.

4. The medical instrument of claim 1, wherein the medical instrument further comprises a breast restraint configured for fixing the breasts on the breast support.

5. The medical instrument of claim 4, wherein the breast restraint is a planar breast restraint configured for compressing the breasts against the breast support.

6. The medical instrument of claim 4, wherein the breast restraint is a three-dimensional printed breast restraint configured for fixing a location of the breasts against the breast support.

7. The medical instrument of claim 4, wherein the breast restraint comprises a flexible receptable comprising breast cups configured to restrain the breasts.

8. The medical instrument of claim 7, wherein the breast restraint further comprises a multi-channel magnetic resonance imaging coil configured for imaging the breasts and axillary lymph nodes of the subject during the magnetic resonance imaging examination.

9. The medical instrument of claim 1, wherein the medical instrument comprises a multi-channel magnetic resonance imaging coil imbedded within the breast support, wherein the multi-channel magnetic resonance imaging coil is configured for imaging the breasts and the axillary lymph nodes of the subject during the magnetic resonance imaging examination.

10. The medical instrument of claim 1, wherein the medical instrument further comprises a magnetic resonance imaging system configured to acquire magnetic resonance imaging data from an imaging zone during the magnetic resonance imaging examination, and wherein the subject support is configured to support the breasts of the subject within the imaging zone.

11. The medical instrument of claim 10, wherein the medical instrument further comprises: a memory storing machine executable instructions and pulse sequence commands, wherein execution a processor configured for controlling the medical instrument, wherein execution of the machine executable instructions causes the processor to: acquire the magnetic resonance imaging data by controlling the magnetic resonance imaging system with the pulse sequence commands; and reconstruct at least one magnetic resonance image from the magnetic resonance imaging data.

12. The medical instrument of claim 10, wherein the medical instrument further comprises a breast biopsy system, and wherein the magnetic resonance imaging system is configured for guiding the breast biopsy system.

13. The medical instrument of claim 10, wherein the medical instrument further comprises a radiotherapy system configured for irradiating a target zone, wherein the target zone is within the imaging zone, wherein the memory further contains radiotherapy system control commands configured for controlling targeting of the radiotherapy system, wherein execution of the machine executable instructions further causes the processor to: adjust the radiotherapy system control commands using the at least one magnetic resonance image; and irradiate the target zone by controlling the radiotherapy system with the adjusted radiotherapy system control commands.

14. A method of operating a medical instrument, wherein the medical instrument comprises a subject support configured for supporting a subject in a Fowler's position during a magnetic resonance imaging examination, wherein the subject support comprises a leg region support region configured for supporting a leg region of the subject during the magnetic resonance imaging examination, wherein the subject support further comprises a thoracic support region configured for supporting an upper body region of the subject, wherein the thoracic support is inclined with respect to the leg support region to hold the subject in the partially reclining position; a breast support, wherein the breast support comprises a planar support surface configured for supporting breasts of the subject, wherein the breast support is connected to the subject support, wherein the planar support surface is horizontal during the magnetic resonance imaging examination; and a magnetic resonance imaging system configured to acquire magnetic resonance imaging data from an imaging zone, and wherein the subject support is configured to support the breasts of the subject within the imaging zone; wherein the method comprises: placing the subject on the subject support; adjusting the breast support such that the planar support surface is under the breasts of the subject and above the heart of the subject; controlling the subject support to move the breasts into the imaging zone; acquire magnetic resonance imaging data by controlling the magnetic resonance imaging system with pulse sequence commands; and reconstruct at least one magnetic resonance image from the magnetic resonance imaging data.

15. The method of claim 14, wherein the medical instrument further comprises a flexible breast restraint comprising breast cups configured to restrain the breasts to the breast support, wherein the flexible breast restraint further comprises a multi-channel magnetic resonance imaging coil configured for imaging the breasts and axillary lymph nodes of the subject, and wherein the method further comprises: attaching the flexible breast restraint to the breast support to immobilize the breasts; and optionally placing a cushion between the breasts and the axillary lymph nodes, wherein the cushion is formed from a magnetic field homogenizing material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In the following preferred embodiments of the invention will be described, by way of example only, and with reference to the drawings in which:

[0055] FIG. 1 illustrates an example of a medical instrument;

[0056] FIG. 2 illustrates a further example of a medical instrument;

[0057] FIG. 3 illustrates a further example of a medical instrument;

[0058] FIG. 4 illustrates a further example of a medical instrument;

[0059] FIG. 5 illustrates a further example of a medical instrument;

[0060] FIG. 6 illustrates a further example of a medical instrument;

[0061] FIG. 7 illustrates an example of a breast restraint;

[0062] FIG. 8 illustrates a further example of a medical instrument;

[0063] FIG. 9 illustrates a further example of a medical instrument; and

[0064] FIG. 10 illustrates a method of operating a medical instrument.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0065] Like numbered elements in these figures are either equivalent elements or perform the same function. Elements which have been discussed previously will not necessarily be discussed in later figures if the function is equivalent.

[0066] FIG. 1 illustrates an example of a medical instrument 100. The medical instrument 100 comprises a subject support 102 with a leg support region 104 and a thoracic support region 106. The thoracic support region 106 is inclined by an incline angle 108 with respect to the leg support region 104. This holds a subject 110 in a Fowler's position.

[0067] There is a breast support 114 that has a planar support surface 116 configured for receiving the breasts 112 of the subject 110. These are able to hold the breasts 112 such that there is minimal compression of the breasts during a magnetic resonance examination.

[0068] FIG. 2 shows a further example of medical instrument 200. The medical instrument 200 is similar except that it additionally comprises a breast restraint 202. The breast restraint 202 is configured for fixing the breasts 112 on the planar support surface 116. For example, there may be attachment points or other means of attaching the breast restraint 202. The breast restraint 202 may take different forms in different examples. In some examples the breast restraint may be a planar breast restraint. This may result in the compression of the breasts but it may for example be useful in taking synthetic X-rays that are equivalent to mammograms. In other examples the breast restraint could be a three-dimensional printed breast restraint. This may for example be particularly useful for radiotherapy operations for positioning the breasts in identical positions through multiple radiotherapy sessions. In another example the breast restraint could be a fabric receptacle that comprises breast cups that are configured to restrain the breasts with a minimal compression. These may also include various magnetic resonance antennas that are incorporated into the breast cups and other portions of the fabric receptacles. For example, the fabric of the breast restraint could also contain additional coils such that they can be positioned near the axillary lymph nodes.

[0069] FIG. 3 shows a further example of a medical instrument 300. The medical instrument is similar to the medical instrument depicted in FIG. 2 except it additionally comprises a magnetic resonance imaging system 302. The breast restraint 202 also functions as a multi-element or coil radio frequency coil.

[0070] The magnetic resonance imaging system 302 comprises a magnet 304. The magnet 304 is a superconducting cylindrical type magnet with a bore 306 through it. The use of different types of magnets is also possible; for instance it is also possible to use both a split cylindrical magnet and a so called open magnet. A split cylindrical magnet is similar to a standard cylindrical magnet, except that the cryostat has been split into two sections to allow access to the iso-plane of the magnet, such magnets may for instance be used in conjunction with charged particle beam therapy. An open magnet has two magnet sections, one above the other with a space in-between that is large enough to receive a subject: the arrangement of the two sections area similar to that of a Helmholtz coil. Open magnets are popular, because the subject is less confined. Inside the cryostat of the cylindrical magnet there is a collection of superconducting coils.

[0071] Within the bore 306 of the cylindrical magnet 304 there is an imaging zone 308 where the magnetic field is strong and uniform enough to perform magnetic resonance imaging. A region of interest 309 is shown within the imaging zone 308. The magnetic resonance data that is acquired typically acquired for the region of interest. The subject support 102 supports a subject 110 within the imaging zone 308 and the region of interest 309.

[0072] Within the bore 306 of the magnet there is also a set of magnetic field gradient coils 310 which is used for acquisition of preliminary magnetic resonance data to spatially encode magnetic spins within the imaging zone 308 of the magnet 304. The magnetic field gradient coils 310 connected to a magnetic field gradient coil power supply 312. The magnetic field gradient coils 310 are intended to be representative. Typically magnetic field gradient coils 310 contain three separate sets of coils for spatially encoding in three orthogonal spatial directions. A magnetic field gradient power supply supplies current to the magnetic field gradient coils. The current supplied to the magnetic field gradient coils 310 is controlled as a function of time and may be ramped or pulsed.

[0073] Adjacent to the imaging zone 308 is the radio-frequency coil within the breast restraint 202. The radio frequency coil 202 is configured for manipulating the orientations of magnetic spins within the imaging zone 308 and for receiving radio transmissions from spins also within the imaging zone 308. The radio frequency antenna 202 may contain multiple coil elements. The radio frequency antenna may also be referred to as a channel or antenna. The radio-frequency coil 202 is connected to a radio frequency transceiver 316. The radio frequency transceiver 316 may be replaced by a separate transmitter and receiver. It is understood that the radio-frequency coil 202 and the radio frequency transceiver 316 are representative. The radio-frequency coil 202 is intended to also represent a dedicated transmit antenna and a dedicated receive antenna. Likewise the transceiver 316 may also represent a separate transmitter and receivers. The radio-frequency coil 202 may also have multiple receive/transmit elements and the radio frequency transceiver 316 may have multiple receive/transmit channels. For example if a parallel imaging technique such as SENSE is performed, the radio-frequency could 202 will have multiple coil elements.

[0074] The magnetic resonance imaging system 302 is further shown as comprising a computer 302 which has a hardware interface 322 that enables the processor 324 to send and receive commands to control the magnetic resonance imaging system 302. The processor 324 is connected to the hardware interface 322, the optional user interface 326 and a memory 328. The hardware interface 322 is any interface which may enable the processor 324 to exchange commands and controls and data with other components of the magnetic resonance imaging system 302. The breast restraint 202, which also functions as a radio frequency coil, is shown as being connected to the transceiver 316. The transceiver 316 and the gradient controller 312 are shown as being connected to the hardware interface 106 of a computer system 102.

[0075] The memory 328 may be any memory which is accessible to the processor 324. It may also be an example of a non-transitory storage medium.

[0076] The memory 328 is shown as containing machine-executable instructions. The machine-executable instructions 330 contain commands which enable the processor 324 to control the operating and function of the medical instrument 300. The machine-executable instructions 330 may also enable the processor 324 to perform various data processing and image processing tasks. The memory 328 is further shown as containing pulse sequence commands 332. The pulse sequence commands are commands or data which may be converted into such commands that enable the processor 324 to control the magnetic resonance imaging system 302 to acquire magnetic resonance imaging data. The memory 328 is further shown as containing magnetic resonance imaging data 334 that has been acquired by controlling the magnetic resonance imaging system 302 with the pulse sequence commands 332. The memory 328 is further shown as containing a magnetic resonance image 336 that has been reconstructed from the magnetic resonance imaging data 334.

[0077] FIG. 4 shows a further example of a medical instrument 400. The medical instrument 400 is similar to the medical instrument 300 depicted in FIG. 3 except that it additionally comprises a breast biopsy system 402. The breast biopsy system may be a manual system or an automated system which may be used for performing a breast biopsy. In particular the biopsy needle or system 402 may be adapted such that its position can be ascertained or determined using the magnetic resonance image 336. By repeatedly acquiring the magnetic resonance image 336 it may enable a healthcare provider to guide the biopsy of the breasts.

[0078] FIG. 5 shows a further example of a medical instrument 500. The medical instrument 500 is similar to the medical instrument 300 depicted in FIG. 3 except that it additionally comprises a radiotherapy system 502. The radiotherapy system 502 could for example be a linear accelerator or other radiotherapy system. The radiotherapy system 502 is configured for irradiating a target zone 504 within the imaging zone 308. The memory 328 is shown as comprising radiotherapy system control commands 506. These commands are adapted for steering the location of the target zone 504. Execution of the machine-executable instructions 330 may cause the processor 324 to adjust the radiotherapy system control commands 506 using the magnetic resonance image 336. By repeatedly acquiring the magnetic resonance image 336 the radiotherapy of the subject 110 may be guided by the magnetic resonance imaging system 302. In some examples, the magnetic resonance imaging coils adjacent to the breast region may be removable to facilitate irradiating the target zone 504.

[0079] FIG. 6 illustrates a further example of a medical instrument 600. In this example the breast support 114 comprises two edge supports 602 which are each attached to the thoracic support region 106. FIG. 6 shows a top 604 and a side view 606. The planar support surface 116 slides along the edge supports 602 to make it adjustable. The subject can repose in the subject support 102 and then the planar support surface 116 can be comfortably adjusted to fit the particular subject by adjusting the position of the planar support surface 116 along the direction of the arrow 608.

[0080] In this example there are mechanical attachments 118 extending to the subject support to rigidly attach the breast support 114 to the subject support.

[0081] The edge supports 602 may be arm rests. This may be beneficial, because supporting the arms on the arm rests 602 may facilitate imaging the axillary lymph nodes.

[0082] FIG. 7 shows a further example of a breast restraint 202. This breast restraint 202 is made of a flexible material such as a fabric or sheet of plastic and comprises two breast cups 700. Within the breast cups there are breast coil elements 702. There are also additional lymph node coil elements 704 that can be positioned near the axillary lymph nodes of the subject. In some examples, the breast restraint 202 may also comprise connections to the table or thoracic support so that the lymph node coil elements 704 are held in position near the lymph nodes. On each side is a connector 706 which may be used to connect the breast restraint 202 to the breast support.

[0083] In other examples, the breast restraint 202 may be wearable. This may have the advantage that the subject can conveniently wear with breast restraint with the coils in advance.

[0084] FIG. 8 shows a further example of the breast support 114 from FIG. 6. In this example the planar support surface 116 has been modified by embedding coil elements 702 and 704 within it. In this case the breast support 114 functions as the magnetic resonance imaging coil also. The placement of the lymph node coil elements 704 on the arm rests 602 may facilitate imaging the axillary lymph nodes.

[0085] The examples described herein may implement the various coil elements 702, 704 as digital coil elements. For example, the subject support may have a connection that receives a fiber optic connection from the coils 702 or 704. This may have the advantage of improving the SNR of the receive coils 702, 704.

[0086] Breast cancer is the most prevalent cancer of women. The golden standard in breast screening and scanning typically is done with different modalities such as ultra-high-resolution Mammography, ultra sound echo and biopsy. MR Breast imaging and screening is very promising but lacks behind in terms of SNR, resolution, B0 and B1 inhomogeneity in the regions of the breast and lymph nodes. Examples may provide for a comfortable and motion robust patient and multi-channel “microscopy” coil setup that enables thin slice, ultra-high-resolution imaging of the breast and lymph nodes avoiding the cardiac region and guaranteeing B0 and B1 homogeneity.

[0087] MR Breast imaging and screening of cancer is very promising. It however lags behind with respect to SNR, resolution and motion robustness of the breast and lymph nodes within acceptable scan time. B0 and B1 homogeneity effects can also lead to distortions and saturation effects.

[0088] The invention proposes a motion robust patient and multi-channel “microscopy capable” coil setup that enables thin slice, ultra-high resolution imaging of the breast and lymph nodes removing the effect of motion avoiding the cardiac region and providing patient comfort.

Embodiments may contain one or more of the following features: [0089] Patient and flexible multi-channel “microscopy” coil setup covering breasts and lymph nodes simultaneously with the breasts fixed via a subject support construction to avoid motion and enable digital connection. [0090] Mechanical fixation of the breast involves a two or more plane fixation, one with a push up effect located under the breast fixed to the subject support and others with a blocking function against breast movement and tissue relaxation. [0091] Patient positioned in a comfortable half sitting supine position which allows a small scan volume selection covering breast and lymph nodes simultaneously avoiding the heart region [0092] Use of B0 and B1 field homogenizing material between breast and lymph node

[0093] Embodiments may provide for a means to position the patient in a comfortable angled supine position supported by a patient cushion construction fixed to the subject support. The Breasts are positioned on a stable table construction fixed to the patient cushion (see FIG. 9 below) or subject support to reduce breathing motion. Extra measure to block breast movements and relaxation effects can be accomplished by a top construction or bra form that flattens the breasts similar to mammography however not compressing them (a breast restraint 202). Secondary, the breasts and lymph nodes are covered by a flexible multi-channel “microscopy” coil set up optimizing the SNR in the breast and lymph node region. The flexible coil setup guarantees a better patient comfort and good coverage into the lymph nodes. The angled patient position enables breast and lymph node scanning within the same ultra-thin imaging plane avoiding the cardiac region. High SNR, ultra-high resolution is guaranteed. Advantage over existing patient and coil set-up where breasts are hanging in a prone patient position is that breasts are fixed and tissue relaxation over time are avoided. SNR and slice coverage may be optimized minimizing the effects from cardiac motion, B0 and B1 effects using homogenizing material. The subject support construction integrates an easy digital connection of the multi-channel coil elements to the subject support.

[0094] Embodiments may provide for a multi-channel “microscopy” and patient setup allows the unique capability to provide ultra-high resolution and SNR of the breasts and lymph nodes avoiding the cardiac region with a comfortable half sitting position.

[0095] FIG. 9 shows a conceptual diagram of a medical instrument 900. It comprises again a subject support 102 as depicted in the previous Figs. The breast restraint 202 in this case is shown as being a compressive plate for compressing the breasts. The breast support 114 is shown as being positioned below the breasts 112 but above the heart 904. The breast support 114 also is below the lymph nodes 902 of the subject 110. In some examples the subject support 102 may also have connections which provide a digital connection to connect to receive coils such as may be included in the breast support 114 and/or the breast restraint 202.

[0096] FIG. 10 illustrates a method of operating the medical instrument of FIG. 3, 4, or 5. In step 1000, the subject is placed on the subject support 102. Next in step 1002, the beast support 114 is adjusted such that the planar support surface 116 is under the breasts or breast 112 of the subject 110 and above the heart 904 of the subject. Then in step 1004 the subject support 102 is moved such that the breasts 112 and/or the axillary lymph nodes are within the imaging zone 308. In step 1006 magnetic resonance imaging data 334 is acquired by controlling the magnetic resonance imaging system 302 with pulse sequence commands 332. Finally, in step 1008 at least one magnetic resonance image is reconstructed 1008 from the magnetic resonance imaging data 334.

[0097] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments.

[0098] Other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed invention, from a study of the drawings, the disclosure, and the appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measured cannot be used to advantage. A computer program may be stored/distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. Any reference signs in the claims should not be construed as limiting the scope.

LIST OF REFERENCE NUMERALS

[0099] 100 medical instrument [0100] 102 magnetic resonance support [0101] 104 leg support region [0102] 106 thoracic support region [0103] 108 incline angle [0104] 110 subject [0105] 112 breasts [0106] 114 breast support [0107] 116 planar support surface [0108] 118 mechanical attachment [0109] 200 medical instrument [0110] 202 breast restraint [0111] 300 medical instrument [0112] 302 magnetic resonance imaging system [0113] 304 magnet [0114] 306 bore of magnet [0115] 308 imaging zone [0116] 309 region of interest [0117] 310 magnetic field gradient coils [0118] 312 magnetic field gradient coil power supply [0119] 316 transceiver [0120] 320 computer [0121] 322 hardware interface [0122] 324 processor [0123] 326 user interface [0124] 328 memory [0125] 330 machine executable instructions [0126] 332 pulse sequence commands [0127] 334 magnetic resonance imaging data [0128] 336 magnetic resonance image [0129] 400 medical instrument [0130] 402 breast biopsy system [0131] 500 medical instrument [0132] 502 radiotherapy system [0133] 504 target zone [0134] 506 radiotherapy system control commands [0135] 600 medical instrument [0136] 602 edge support [0137] 604 top view [0138] 606 side view [0139] 608 direction of motion [0140] 700 breast cups [0141] 702 breast coil elements [0142] 704 lymph node coil elements [0143] 706 connection to table [0144] 800 coil elements [0145] 900 medical instrument [0146] 902 lymph nodes [0147] 904 heart [0148] 1000 placing the subject on the subject support [0149] 1002 adjusting the breast support such that the planar support surface is under the breasts of the subject and above the heart of the subject [0150] 1004 controlling the subject support to move the breasts into the imaging zone [0151] 1006 acquire magnetic resonance imaging data by controlling the magnetic resonance imaging system with pulse sequence commands [0152] 1008 reconstruct at least one magnetic resonance image from the magnetic resonance imaging data