Magnetic resonance imaging of the coronary arteries: clinical results fromthree dimensional evaluation of a respiratory gated technique

Background-Magnetic resonance coronary angiography is challenging because o f the motion of the vessels during cardiac contraction and respiration. Add itional challenges are the small calibre of the arteries and their complex three dimensional course. Respiratory gating, turboflash acquisition, and v olume rendering techniques may meet the necessary requirements for appropri ate visualisation. Objective-To determine the diagnostic accuracy of respiratory gated magneti c resonance imaging (MRI) for the detection of significant coronary artery stenoses evaluated with three dimensional postprocessing software. Methods-32 patients referred for elective coronary angiography were studied with a retrospective respiratory gated three dimensional gradient echo MRI technique. Resolution was 1.9 x 1.25 x t mm. After manual segmentation thr ee dimensional evaluation was performed with a volume rendering technique. Results-Overall 74% (range 50% to 90%) of the proximal and mid coronary art ery segments were visualised with an image quality suitable for further ana lysis. Sensitivity and specificity for the detection of significant stenose s were 50% and 91%, respectively. Conclusions-Volume rendering of respiratory gated MRI techniques allows ade quate visualisation of the coronary arteries in patients with a regular bre athing pattern. Significant lesions in the major coronary artery branches c an be identified with a moderate sensitivity and a high specificity.