Validation of a high-resolution, phase contrast cardiovascular magnetic resonance sequence for evaluation of flow in coronary artery bypass grafts.
The aim was to validate a magnetic resonance high-resolution, phase-contrast sequence for quantifying flow in small and large vessels and to demonstrate its feasibility to measure flow in coronary artery bypass grafts. A breathhold, echo planar imaging (EPI) sequence was developed and validated in a flow phantom using a fast field echo (FFE) sequence as reference. In 17 volunteers aortic flow was measured using both sequences. In 5 patients flow in the left internal mammary artery (LIMA) and aorta was measured at rest and during adenosine stress, and coronary flow reserve (CFR) was calculated; in 7 patients, vein graft flow velocity was measured. In the flow phantom measurements, the EPI sequence yielded an excellent correlation with the FFE sequence (r = 0.99; p < 0.001 for all parameters). In healthy volunteers, aortic volume flow correlated well (r = 0.88; p < 0.01), with a minor overestimation. It was feasible to measure flow velocity in the LIMA and vein grafts of the 12 patients. The high-resolution, breathhold cardiovascular magnetic resonance velocity-encoded sequence correlated well with a free-breathing, FFE sequence in a flow phantom and in the aortae of healthy volunteers. Using the EPI sequence, it is feasible to measure flow velocity in both LIMA and vein grafts, and in the aorta.
Salm
Liesbeth P
LP
Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands.
Schuijf
Joanne D
JD
Lamb
Hildo J
HJ
Bax
Jeroen J
JJ
Vliegen
Hubert W
HW
Jukema
J Wouter
JW
van der Wall
Ernst E
EE
de Roos
Albert
A
Doornbos
Joost
J
D000328:Adult; D000368:Aged; D001013:Aorta, Thoracic / Q000502:physiology*; D001783:Blood Flow Velocity; D017023:Coronary Angiography; D001026:Coronary Artery Bypass; D017352:Echo-Planar Imaging / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008323:Mammary Arteries / Q000502:physiology*; D008875:Middle Aged; D019047:Phantoms, Imaging