Breath-hold MR measurements of blood flow velocity in internal mammary arteries and coronary artery bypass grafts

✍ Scribed by Hajime Sakuma; Sebastian Globits; Margaret O'sullivan; Ann Shimakawa; Matt A. Bernstein; Thomas K. F. Foo; Thomas M. Amidon; Kan Takeda; Tsuyoshi Nakagawa; Charles B. Higgins

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 547 KB
• Volume: 6
• Category: Article
• ISSN: 1053-1807
• DOI: 10.1002/jmri.1880060138

✦ Synopsis

Breath

-hold velocity-encoded cine M R (VENC-MR) im-aginS is a feasible method for measuring phasic blood flow velocity in small vessels that move during respiration. The purposes of the current study are to compare breathhold VENC-MR measurements of flow velocities in the internal mammary arteries (m with nonbreath-hold measurements and to characterize the systolic and diastolic flow velocity curves in a cardiac cycle in native IMA and IMA grafts. Flow velocity in 30 native IMA and 8 IMA grafts were evaluated with a breath-hold VENC-MR sequence with K-space segmentation and view-sharing reconstruction(TR/TE = 16/9 msec, VENC = 100 cm/s). In 10 native IRE& nonbreathhold VENC-MR images wen acquired as well for comparison. Breath-hold VENC-MR imaging showed signif& cantly hlgher systolic and diastolic peak velocities in native IMA (43.1 cm/second f 15.0 and 10.0 cm/second f 4.8). in comparison to those of nonbreath-hold VENC-MRhaging (27.6 cm/second ? 10.2 and 7.3 cm/

second f 3.9, P < .OS). The diastolic/systolic peak velocity ratio in the IMA grafts (.a8 f .41) was signilacantly higher than that in native IMA (.24 f .08, P < .01). Interobserver variability in the flow velocity measurement was less than 4%. Breath-hold VENC-MR imaging demonstrated higher peak flow velocity in the IMA than nonbnath-hold VENC-MR imaging. This technique is a rapid and effective method for the noninvasive assessment of blood flow velocity in IMA grafts. Index tern: Magnetic resonance imaging * Internal mammary artery Coronary artery bypass graft JMRI 1996; 1:219-222 Coronary flow * Rapid MR imaging Abbreviations: IMA = internal mammary artery, ECG = electrocardiogram. VEtiC-MR = velocity-encoded cine MR. RO1 = region-of-interest. GRASS = gradient-recalled acquisitlon in the steady state.