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
  • G01R33/38—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field
  • G01R33/381—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field using electromagnets
  • G01R33/3815—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field using electromagnets with superconducting coils, e.g. power supply therefor
• • 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
• • 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
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F6/00—Superconducting magnets; Superconducting coils
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
  • H01F6/00—Superconducting magnets; Superconducting coils
  • H01F6/06—Coils, e.g. winding, insulating, terminating or casing arrangements therefor

Definitions

• the magnet is not limited to a two-layer coil structure, and a multi-layer coil structure can be used for the producing a half-compact magnet.
• the small ⁇ corresponds to small imaging area or large accessible distance (equivalently long-bore magnet), the large ⁇ corresponds to large imaging area and/or small accessible distance (effective short-bore magnet).
• low stray fields e.g., a calculated stray magnetic field external to the magnet that is less than 5 x 1 ⁇ "4 Tesla at all locations greater than 7m (for whole, body system) and 4m (for extremity system) meters from the dsv geometrical centre).
• Figures 1 shows in perspective the relative sizes of the coils and the dsv, indicating a close, large dsv compared to the total magnet length and thus enabling the imaging of whole body, for example, with the patient comfortably positioning on the bed with head outside the magnet during examinations (as shown in Fig. 2).
• the distance 'd' from the edge of the dsv to the patient end of the magnet is 36 centimetres, which is the same as conventional short bore designs.
• a small sized dsv e.g. 30cm instead of conventional 40-45cm in the axial direction
• This example of the present invention overcomes the technical challenges and produces the imaging region whose size is 1.8 times of the one offered by conventional short-bore technology.
• the primary layer of the magnet has a total current distribution function which is asymmetric with respect to the imaging centre along the longitudinal axis, i.e., the total current on the patient side is larger than that on the service side.
• the magnets of 3T extremity examples also have such asymmetric current distribution functions.
• Example 2 (3T extremity magnet (versions a, b))
• the coils are necessarily in close proximity, and the magnetic forces that act on the superconducting windings can be very large. These forces can cause the superconducting alloys to perform below their rated properties or even to quench and cease superconducting.
• the consideration of magnetic forces in the design process is important for such a system and therefore in this embodiment automated force reduction is included in the design process, that is, the optimization includes Maxwell forces in the error function to be minimized.

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

Priority Applications (6)

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Publications (1)

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• 2010
  • 2010-12-20 WO PCT/AU2010/001714 patent/WO2011075770A1/en not_active Ceased
  • 2010-12-20 DE DE112010004900.9T patent/DE112010004900B4/de active Active
  • 2010-12-20 GB GB1212991.2A patent/GB2489378B/en active Active
  • 2010-12-20 AU AU2010336013A patent/AU2010336013B2/en active Active
  • 2010-12-20 US US13/518,117 patent/US20120258862A1/en not_active Abandoned
  • 2010-12-20 JP JP2012545013A patent/JP5805655B2/ja active Active
  • 2010-12-20 CN CN201080057184.5A patent/CN102667517B/zh active Active

Patent Citations (3)

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