High-spatial-resolution contrast-enhanced MR angiography of the renal arteries: A prospective comparison with digital subtraction angiography

PURPOSE: To evaluate a high-spatial-resolution three-dimensional (3D) contr ast material-enhanced magnetic resonance (MR) angiographic technique for de tecting proximal and distal renal arterial stenosis. MATERIALS AND METHODS: Twenty-five patients underwent high-spatial-resoluti on small-field-of-view (FOV) 3D contrast-enhanced MR angiography of the ren al arteries, which was followed several minutes later by more standard, lar ge-FOV 3D contrast-enhanced MR angiography that included the distal aorta a nd iliac arteries. For both acquisitions, MR fluoroscopic triggering and an elliptic centric view order were used. Two readers evaluated the MR angiog rams for grade and hemodynamic significance of renal arterial stenosis, dia gnostic quality, and presence of artifacts. MR imaging results for each pat ient were compared with those of digital subtraction angiograms. RESULTS: The high-spatial-resolution small-FOV technique provided high sens itivity (97%) and specificity (92%) for the detection of renal arterial ste nosis, including all four distal stenoses encountered. The portrayal of the segmental renal arteries was adequate for diagnosis in 19 (76%) of 25 pati ents. In 12% of the patients, impaired depiction of the segmental arteries was linked to motion. CONCLUSION: The combined high-spatial-resolution small-FOV and large-FOV MR angiographic examination provides improved spatial resolution in the regio n of the renal arteries while maintaining coverage of the abdominal aorta a nd iliac arteries.