Cardiac echo-planar MR imaging: comparison of single- and multiple-shot techniques.
OBJECTIVE
To compare the quality of cardiac images acquired with two-and four-shot echo-planar imaging (EPI) with that of images acquired with single-shot EPI.


METHODS
Single-, two-, and four-shot EPI was performed to obtain axial images that traversed both cardiac ventricles. The subjects were 10 healthy men whose ages ranged from 22 to 38 years (mean, 27 years). The multiple-shot EPI data were acquired in snapshot (sequential) and cardiac-gated (non-sequential) modes. Image quality was compared by evaluation of the depiction of cardiac structures and analysis of signal intensity, contrast, and signal homogeneity.


RESULTS
Multiple-shot EPI depicted the coronary and internal mammary arteries better than did single-shot EPI (P < .05). Intraventricular signal intensity was more homogeneous on multiple-shot images (P < .005). Cardiac-gated acquisition resulted in less image blurring and allowed acquisition of more phases per RR interval.


CONCLUSIONS
Multiple-shot EPI rendered higher quality images than did single-shot EPI.
Wetter
D R
DR
Department of Radiology, University Hospital Zurich, Switzerland.
McKinnon
G C
GC
Debatin
J F
JF
von Schulthess
G K
GK
D000328:Adult; D003326:Coronary Circulation; D017352:Echo-Planar Imaging / Q000379:methods*; D006321:Heart / Q000033:anatomy & histology*; D006339:Heart Rate; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D009200:Myocardial Contraction