Rapid polarizing field cycling in magnetic resonance imaging.
We describe the electronics for controlling the independently pulsed polarizing coil in a prepolarized magnetic resonance imaging (PMRI) system and demonstrate performance with free induction decay measurements and in vivo imaging experiments. A PMRI scanner retains all the benefits of acquiring MRI data at low field, but with the higher signal of the polarizing field. Rapidly and efficiently ramping the polarizing coil without disturbing the data acquisition is one of the major challenges of PMRI. With our modular hardware design, we successfully ramp the 0.4-T polarizing coil of a wrist-sized PMRI scanner at up to 100 T/s without causing image artifacts or otherwise degrading data acquisition.
Matter
Nathaniel I
NI
Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, CA 94305-9510, USA. nmatter@mrsrl.stanford.edu
Scott
Greig C
GC
Grafendorfer
Thomas
T
Macovski
Albert
A
Conolly
Steven M
SM
D017076:Computer-Aided Design; D004582:Electronics, Medical; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D007089:Image Enhancement / Q000295:instrumentation* / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods; D008280:Magnetics / Q000295:instrumentation*; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers