ILIAC ARTERY-STENOSIS MEASUREMENTS - COMPARISON OF 2-DIMENSIONAL TIME-OF-FLIGHT AND 3-DIMENSIONAL DYNAMIC GADOLINIUM-ENHANCED MR-ANGIOGRAPHY

OBJECTIVE, We compared our ability to make iliac artery measurements o n two-dimensional (2D) time-of-flight (TOF) and three-dimensional dyna mic gadolinium-enhanced MR angiography with conventional angiography. SUBJECTS AND METHODS, Fifteen patients with lower extremity vascular d isease underwent pelvic MR angiography, Parameters of the cardiac-gate d axial 2D TOF sequence included a TR/TE of 24/7 msec and a 50 degrees flip angle. Parameters for the three-dimensional MR angiography seque nce, in which we obtained 32 coronal 3-mm slices with fat suppression, included a TRITE of 32/5 msec and a 40 degrees flip angle during infu sion of 40 ml of gadolinium-chelated contrast material. Patients then underwent conventional angiography of the iliac arteries, Maximum sten osis in the common iliac, external iliac, and common femoral arteries was then measured. Measurements of stenosis were compared by repeated measures of analysis of variance. Sensitivity and specificity were cal culated for identification of greater than or equal to 50% stenosis an d less than 50% stenosis, RESULTS, For all vessels studied, we found n o significant difference in measurements obtained from the gadolinium- enhanced MR angiography technique and those obtained from conventional angiography (p > .05). However, significantly different stenotic meas urements were obtained from the 2D TOF MR angiography sequence and con ventional angiography. In the external iliac arteries, 2D TOF MR angio graphy exaggerated stenoses most substantially. Gadolinium-enhanced MR angiography achieved 100% sensitivity and specificity. CONCLUSION. Dy namic gadolinium-enhanced MR angiography was more accurate than 2D TOF MR angiography when measuring degree of stenosis in the iliac arterie s.