Blood flow imaging of cardiovascular system by cine magnetic resonance

In order to obtain the blood flow images in patients with cardiovascular diseases, we performed cine magnetic resonance (MR) imaging using 1.5 tesla superconductive magnetic system in 41 patients with a variety of heart diseases. Rapid MR imaging technique (FLASH, flip angle=30deg, TR=35-55 msec, TE=15-22 msec) was applied to collect 11-25 frames throughout one cardiac cycle in three orthogonal planes (transverse, coronal and sagittal) and oblique planes perpendicular to the orthogonal planes. These images were displayed in cine mode on CRT for detection of flow pattern. In 20 patients with valvular insufficiency (AR: 6 patients, MR: 6 patients, TR: 4 patients, PR 4 patients), intracavital blood was imaged as high signal intensity, while surrounding cardiac structures had somewhat lower signal intensity. Valvular regurgitations delignated as a signal loss in the receipient chambers were best imaged in coronal plane for AR, in transverse plane for MR and TR and in oblique plane for PR. In 7 patients with arteriosclerotic aneurysm, fusiform dilatations of thoracic or abdominal aorta were observed in coronal and sagittal planes. Blood flow was displayed as a high-signal intensity. Thrombi attached to the aortic vessel wall were well differentiated from the arterial vessel. Intimal flap, true lumen and false lumen were well visualized with cine MR imaging in 4 patients with aortic dissection. Blood flow through entry was observed as a signal loss. Coronary blood flow at the proximal portion of coronary trees was also delineated as high-signal intensity in 10 patients. But phasic change of coronary flow was not visualized. These results indicated that cine MR imaging was a useful tool for detection and evaluation of blood flow in cardiovascular diseases. (author)