Effective motion-sensitizing magnetization preparation for black blood magnetic resonance imaging of the heart.
OBJECTIVE
To investigate the effectiveness of flow signal suppression of a motion-sensitizing magnetization preparation (MSPREP) sequence and to optimize a 2D MSPREP steady-state free precession (SSFP) sequence for black blood imaging of the heart.


METHODS
Using a flow phantom, the effect of varying field of speed (FOS), b-value, voxel size, and flow pattern on the flow suppression was investigated. In seven healthy volunteers, black blood images of the heart were obtained at 1.5T with MSPREP-SSFP and double inversion recovery fast spin echo (DIR-FSE) techniques. Myocardium and blood signal-to-noise ratio (SNR) and myocardium-to-blood contrast-to-noise ratio (CNR) were measured. The optimal FOS that maximized the CNR for MSPREP-SSFP was determined.


RESULTS
Phantom data demonstrated that the flow suppression was induced primarily by the velocity encoding effect. In humans, FOS=10-20 cm/s was found to maximize the CNR for short-axis (SA) and four-chamber (4C) views. Compared to DIR-FSE, MSPREP-SSFP provided similar blood SNR efficiency in the SA basal and mid-views and significantly lower blood SNR efficiency in the SA apical (P=0.02) and 4C (P=0.01) views, indicating similar or better blood suppression.


CONCLUSIONS
Velocity encoding is the primary flow suppression mechanism of the MSPREP sequence and 2D MSPREP-SSFP black blood imaging of the heart is feasible in healthy subjects.
Nguyen
Thanh D
TD
Department of Radiology, Weill Medical College of Cornell University, New York, New York 10022, USA. tdn2001@med.cornell.edu
de Rochefort
Ludovic
L
Spincemaille
Pascal
P
Cham
Matthew D
MD
Weinsaft
Jonathan W
JW
Prince
Martin R
MR
Wang
Yi
Y
D000328:Adult; D000465:Algorithms; D005260:Female; D006321:Heart / Q000033:anatomy & histology*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009038:Motion; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted