Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R33/00—Arrangements or instruments for measuring magnetic variables
  • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
  • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
  • G01R33/32—Excitation or detection systems, e.g. using radio frequency signals
  • G01R33/34—Constructional details, e.g. resonators, specially adapted to MR
  • G01R33/34084—Constructional details, e.g. resonators, specially adapted to MR implantable coils or coils being geometrically adaptable to the sample, e.g. flexible coils or coils comprising mutually movable parts
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B5/00—Measuring for diagnostic purposes; Identification of persons
  • A61B5/05—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves
  • A61B5/055—Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • A61B2017/00535—Surgical instruments, devices or methods pneumatically or hydraulically operated
  • A61B2017/00557—Surgical instruments, devices or methods pneumatically or hydraulically operated inflatable
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R33/00—Arrangements or instruments for measuring magnetic variables
  • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
  • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
  • G01R33/285—Invasive instruments, e.g. catheters or biopsy needles, specially adapted for tracking, guiding or visualization by NMR

Definitions

• the present invention relates generally to a device for positioning a sensing coil assembly that is placed about a patient's body part within a magnet of a nuclear magnetic resonance imaging machine. More specifically, the present invention relates to an inflatable positioning device for a sensing coil assembly that has an inflatable chamber radially within the coil to position the coil with respect to the patient and an inflatable chamber radially outside of the coil to position the coil with respect to the magnet .
• Sensing coil assemblies are necessary in nuclear magnetic resonance imaging (NMRI) apparatus to produce an image.
• NMRI nuclear magnetic resonance imaging
• Such sensing coil assemblies may be placed around a body part of the patient to be imaged, such as an arm or leg.
• a significant void or empty region occurs between the coil and the body part to be imaged as well as between the coil and the inner surfaces of the magnet when the body part is placed within the magnet.
• Technicians will frequently fill those voids with loose pieces of foam or other available material to position the coil about the portion of the patient to be imaged as well as to position the coil between the poles of the magnet. Accordingly, the technicians first pack , loose foam between the section of the body to be imaged and the coil.
• the technician will place the foam packed coil and section of the body within a gap between two poles of the magnet .
• the area between the coil and the magnet poles is then packed with more foam until the desired position is achieved.
• the technician will then take a quick image to ensure that the body section and coil are properly positioned. If the image is not clear, the entire procedure is repeated until the body section and coil are properly positioned within the magnet gap. Notwithstanding the use of loose pieces of foam to help position the coil, there are still major problems involved. Patients frequently unintentionally move during the imaging process. This accidental movement causes the patient to move from the preferred imaging position, resulting in an unacceptable image.
• an object of the present invention to provide a positioning device for an NMRI sensing coil assembly that properly positions the body part of the patient to be imaged within the coil and properly positions the coil between the poles of the magnet, while simultaneously preventing the patient from accidentally moving the body part during the NMRI process.
• an inflatable NMRI sensing coil assembly positioning device includes a first inflatable chamber disposed radially outwardly of the coil and a second inflatable chamber coil disposed radially inwardly of the coil .
• the first and second inflatable chambers each comprise at least two sections.
• Fig. 1 is a perspective view of an NMRI sensing coil assembly positioning device according to the present invention having a first inflatable chamber disposed about the coil and a second inflatable chamber disposed radially inwardly of the coil;
• Fig. 2 is a plan view of the inflatable coil positioning device of Fig. 1 placed about the arm of a patient and within a magnet;
• Fig. 3 is a cross-sectional view taken along lines 3-3 of Fig. 2 and looking in the direction of the arrows; and Fig. 4 is a cross-sectional view taken along lines
• an inflatable coil positioning device 10 for magnetic resonance imaging (MRI) is illustrated.
• the inflatable coil positioning device 10 includes a first inflatable sleeve 12 disposed radially about a sensing coil assembly 38 and a second inflatable sleeve 14 disposed radially inward of the sensing coil assembly.
• An inflation bulb 16, 18, of the type conventionally used for taking blood pressure with a sphygmomanometer cuff, are used to inflate and deflate the first inflatable sleeve 12 and the second inflatable sleeve 14, respectively.
• the second inflatable sleeve 14 is detachably retained within the coil by the use of complementary hook and loop type fastener material disposed on the under surface of tabs 20.
• the second bladder 14 can be attached by other means, such as snaps, removable rivets, etc.
• the inflatable coil positioning device 10 is shown attached to an arm 22 of a patient and within an MRI magnet 24 of a magnetic resonance imaging machine. Some magnets have a marked -"sweet-spot", indicated as being between reference lines 26 and 28, which is located where the magnetic field is the strongest, and most uniform. Of course, it is preferred that the device 10 be positioned within the sweet-spot of the magnet 24.
• the first inflatable sleeve 12 which is detachably disposed radially about the coil 38, includes two diametrically opposed inflatable sections 30, 32 that are in fluid communication with one another. These sections 30,32 are inflated with inflation bulb 16, which is in fluid communication therewith via a conduit 34 and an arcuate passageway 36 (See Fig. 1) .
• the first sleeve 12 can be comprised of only one section or any number of sections.
• Coil 38 may be a known type of device, see for example, U.S. Patent No. 4,791,372 to Kirk et al . or U.S. Patent No. 4,793,356 to Misic et al . , the disclosures of which are hereby incorporated by reference.
• the coil 38 is coupled to a firm cylindrical sleeve 40 (see Figs. 3 and 4) .
• sleeve 40 is made of a G10 fiberglass sheet having a thickness of 0.03 inches.
• a second firm sleeve 42 is disposed radially about the first sleeve 38 and coil 40, and radially within the first inflatable sleeve 12.
• a third firm sleeve 44 is disposed radially within the coil 38 and first sleeve 40, and radially about the second inflatable sleeve 14.
• the second sleeve 42 and the third sleeve 44 are also made of a G10 fiberglass sheet having a thickness of 0.03 inches.
• a sleeve of foam material 46 is disposed between the coil 38 and sleeve 40, and the second sleeve 42.
• Another sleeve of foam material 48 is disposed between the coil 38 and first sleeve 40, and the third sleeve 44.
• the foam is a velora foam having a thickness of 0.25 inches.
• the electronics associated with operating coil 38 are disposed on the cylindrical outer surface of the second sleeve 42 within a housing 50 and communicate electrically with coil 38 in a known manner.
• the second inflatable sleeve 14, disposed radially within the coil, is illustrated as having seven sections 52, 54, 56, 58, 60, 62 and 64. Each section of the second inflatable sleeve 14 communicates with an adjacent sleeve through a passageway 66. Alternatively, a plurality of passageways could be provided between adjacent sections of the second inflatable sleeve 14. Alternatively, the second sleeve 14 can be comprised of only one section. Additionally, the second inflatable sleeve 14 may be comprised of any number of sections, preferably an even number to evenly support the arm 22 or other portion of the body being imaged. The use of the inflatable coil positioning device 10 will be described below with reference to Figs. 1-4.
• the inflatable coil positioning device 10 is first placed about a so called "target section" of the patient to be imaged by MRI. For example, as illustrated in Fig. 2, the device 10 is attached about the arm 22 of a patient. The second inflatable sleeve 14, disposed radially within the coil 38, is then inflated by use of inflation bulb 18 until the device 10 is firmly mounted on the target section of the patient. The mounted inflatable coil device 10 and the target section of the patient are then positioned within the predetermined sweet-spot of magnet 24.
• Device 10 is aligned within magnet 24, between reference lines 26, 28, such that sections 30, 32 of sleeve 12 are adjacent to the poles of the magnet 24.
• Sleeve 12 is then inflated by using inflation bulb 16 until the device 10 is firmly retained within to the magnet 24 at its sweet-spot.
• the two sections 30, 32 of the inflatable sleeve 12 are inflated until the device 10 is adequately positioned between the two poles of the magnet 24.
• the portions of the sections 30, 32 that contact the poles of the magnet 24 will flatten to a greater degree than illustrated to form a planer contact surface between the poles of the magnet and sections 30, 32.
• the target section of the patient to be imaged is positioned coaxial within coil 38 and is centered within the gap between the two poles of the magnet 24.
• the inflatable coil positioning device of the present invention successfully positions the target section of the body coaxial within the coil and centered within the gap of the magnet. Moreover, successful positioning can be expected upon the first attempt every time. By eliminating the trial and error procedure necessary with existing positioning devices, the present invention substantially decreases the time required for MRI examination of a patient. This would permit more patients to be examined in the course of a day, leading to a reduced cost to the patient. From the foregoing description, it will be appreciated that the present invention makes available a compact, cost efficient coil positioning device.
• the inflatable coil positioning device is designed to allow for simple, efficient operation, while preventing the patient from inadvertently moving with respect to the coil and the magnet.

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• Health & Medical Sciences (AREA)
• Physics & Mathematics (AREA)
• Life Sciences & Earth Sciences (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Engineering & Computer Science (AREA)
• Medical Informatics (AREA)
• Radiology & Medical Imaging (AREA)
• General Physics & Mathematics (AREA)
• Biophysics (AREA)
• Pathology (AREA)
• Condensed Matter Physics & Semiconductors (AREA)
• Biomedical Technology (AREA)
• Heart & Thoracic Surgery (AREA)
• High Energy & Nuclear Physics (AREA)
• Molecular Biology (AREA)
• Surgery (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Magnetic Resonance Imaging Apparatus (AREA)

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• 1993
  • 1993-11-24 US US08/157,984 patent/US5400787A/en not_active Expired - Fee Related
• 1994
  • 1994-11-23 JP JP51527895A patent/JP3504663B2/ja not_active Expired - Fee Related
  • 1994-11-23 AU AU12146/95A patent/AU680079B2/en not_active Ceased
  • 1994-11-23 CN CN94194489A patent/CN1137229A/zh active Pending
  • 1994-11-23 WO PCT/US1994/013749 patent/WO1995014428A1/en not_active Ceased
  • 1994-11-23 PL PL94314697A patent/PL314697A1/xx unknown
  • 1994-11-23 CA CA002177262A patent/CA2177262A1/en not_active Abandoned
  • 1994-11-23 EP EP95903181A patent/EP0734226A1/en not_active Withdrawn
  • 1994-11-24 IL IL11176094A patent/IL111760A0/xx unknown
• 1996
  • 1996-05-23 FI FI962186A patent/FI962186A7/fi not_active Application Discontinuation

Patent Citations (1)

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