A magnetization mapping approach for passive shim design in MRI.
A new passive shim design method is presented which is based on a magnetization mapping approach. Well defined regions with similar magnetization values define the optimal number of passive shims, their shape and position. The new design method is applied in a shimming process without prior-axial shim localization; this reduces the possibility of introducing new errors. The new shim design methodology reduces the number of iterations and the quantity of material required to shim a magnet. Only a few iterations (1-5) are required to shim a whole body horizontal bore magnet with a manufacturing error tolerance larger than 0.1 mm and smaller than 0.5 mm. One numerical example is presented.
Sánchez
H
H
Sch. of Inf. Technol. & Electr. Eng., Queensland Univ., Brisbane, Qld., Australia. hsanchez@itec.uq.edu.au
Liu
F
F
Trakic
A
A
Crozier
S
S
D017076:Computer-Aided Design; D004867:Equipment Design / Q000379:methods; D019544:Equipment Failure Analysis / Q000379:methods; D007089:Image Enhancement / Q000295:instrumentation* / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods; D008280:Magnetics / Q000295:instrumentation*; D011829:Radiation Dosage; D011874:Radiometry / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers