Single-shot versus interleaved echo-planar MR imaging: application to visualization of cardiac valve leaflets.
Visualization of the cardiac valves with standard magnetic resonance (MR) imaging is not adequate because of long acquisition times. Echo-planar imaging (EPI) can, however, be performed with a temporal resolution (30-50 msec) comparable to that of echocardiography. The authors evaluated the feasibility of real-time imaging of cardiac valve motion with ultrafast MR techniques. Eight healthy volunteers and three patients with mitral stenosis and regurgitation were studied with a 1.5-T whole-body imager. Two different EPI sequences were assessed: a standard single-shot gradient-echo EPI (GEPI) sequence and a fast imaging technique based on multiple-shot EPI with interleaved k-space acquisition (IGEPI). Fat-suppressed images with an in-plane resolution of 3.7 x 3.7 mm were obtained equally spaced through the cardiac cycle. Half-k-space acquisition was used. Morphologic evaluation was superior with IGEPI, owing to the better intracavitary signal homogeneity (P < .01), and the mitral valve leaflets were easier to identify on systolic images. IGEPI provided adequate valve visibility in all three patients.
Davis
C P
CP
Department of Medical Radiology, University Hospital, Zürich, Switzerland.
McKinnon
G C
GC
Debatin
J F
JF
Duewell
S
S
von Schulthess
G K
GK
D000328:Adult; D000368:Aged; D004452:Echocardiography; D005260:Female; D006351:Heart Valves / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000503:physiopathology; D008946:Mitral Valve Stenosis / Q000503:physiopathology