Short TI short TR inversion recovery imaging using reduced flip angles.
In this paper the effects of reducing the flip angle of the 90-degree observation pulse in inversion recovery imaging are described and analyzed. When incorporated in an IR sequence with a short inversion time (STIR), reduction to the 90-degree pulse allows a significant shortening of the repetition time without loss in contrast, although at the expense of some signal/noise. The generalized STIR sequence thus combines the previously reported advantages of a conventional STIR sequence--suppression of ghost artifacts from abdominal wall movement, suppression of chemical shift and boundary artifacts, additive effects of N(H), T1 and T2 on image contrast--with reduced power deposition and the advantages resulting from shorter repetition times, viz, single heart-beat triggering, increased number of signal averages for suppression of motion artifacts, acquisition of interleaved contiguous slices without cross-talk or considerable time savings when the number of required slices is limited. The proposed method is demonstrated and experimentally verified by imaging experiments on phantoms and human subjects. In principle the method is applicable to all cases where STIR imaging has been proven to be successful.
Bakker
C J
CJ
Department of Radiology, University Hospital Utrecht, The Netherlands.
Witkamp
T D
TD
Janssen
W M
WM
D001921:Brain / Q000033:anatomy & histology; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008961:Models, Structural