Renal Artery Stenosis: Functional Assessment with Dynamic MR Perfusion Measurements—Feasibility Study

Purpose: To prospectively assess feasibility of renal magnetic resonance (MR) perfusion measurement method based on turbo fast low-angle shot sequences for grading effect of renal artery stenosis (RAS) on parenchymal perfusion. Materials and Methods: Institutional review board approved this study, and patients gave written consent. Seventy-three patients (34 male, 39 female; age range, 17–84 years) who were clinically suspected of having RAS underwent contrast material–enhanced (gadodiamide) saturation-recovery turbo fast low-angle shot imaging for measurement of renal perfusion and high-spatial-resolution MR angiography for RAS detection and grading. Degree of stenosis was evaluated as high grade (≥75% stenosis), low to intermediate grade (>0% to <75% stenosis), or absent. High temporal resolution of the turbo fast low-angle shot sequence allowed acquisition of an exact first-pass tracing of the contrast agent bolus from which a signal intensity (SI)–time curve was derived. On the basis of this curve, me...