PT  - JOURNAL ARTICLE
AU  - T W Stadnik
AU  - R R Luypaert
AU  - E C Neirynck
AU  - M Osteaux
TI  - Optimization of sequence parameters in fast MR imaging of the brain with FLASH.
DP  - 1989 Mar 01
TA  - American Journal of Neuroradiology
PG  - 357--362
VI  - 10
IP  - 2
4099  - http://www.ajnr.org/content/10/2/357.short
4100  - http://www.ajnr.org/content/10/2/357.full
SO  - Am. J. Neuroradiol.1989 Mar 01; 10
AB  - Owing to the intrinsically complex behavior of the signal intensity of fast gradient-refocusing MR sequences, agreement as to the clinically most useful sequence parameters has not yet been reached. This study evaluates the FLASH (fast low-angle shot) sequence for gray-white matter differentiation on normal volunteers at 1.5 T. The FLASH gradient-echo sequence is essentially T1-dependent. For very fast imaging and T1 weighting, the following parameters yield the best results: a flip angle of 30-50 degrees with TR = 20 and TE = 10. To replace T1-weighted SE by the faster FLASH sequence, the best results are achieved by a flip angle of 70-120 degrees with TR = 150-300 and TE = 10 (or shorter, if possible). The most valuable proton-density aspect is achieved by a flip angle of 30 degrees with TR = 300 and TE = 16.