Chang-Hoon Choi1, Gareth R. Davies1, David J. Lurie1
1Bio-Medical Physics and Bio-Engineering, University of Aberdeen, Aberdeen, Scotland, UK
Magnetisation transfer contrast (MTC) imaging normally employs off-resonant irradiation with varying RF offset frequency but maintaining a desired constant RF field strength (B1). This presents the main technical difficulty of MTC at low field, because the larger offset frequencies are likely to be outside the bandwidth of the RF transmit system, causing B1 to vary with the frequency offset. In this work, we demonstrate a novel off-resonance irradiation method using the fast field-cycling technique which permits to counter this problem. The results obtained by the new technique agreed well with those obtained by the conventional technique.