Quantitative analysis of MR perfusion/diffusion images in a dog model of renal artery stenosis with microsphere correlation

This paper compares MR perfusion/diffusion-derived parameters with microsphere determination of asymmetry of renal perfusion in a dog model of renal artery stenosis. A left renal artery stenosis was created by placement of a silk ligature. Nb-95-labeled microspheres were injected into the left ventricle, and a reference blood sample was drawn. The dog was imaged in a 1.5-T MR imager with both spin-echo and turbo-FLASH perfusion/diffusion-sensitive pulse sequences. The kidneys were excised, weighted, divided into sections, and counted. Two dogs have been studied to date. In dog 1, left renal blood flow (RBF) was 42 mL/min/100g and right RBF was 337 mL/min/100g. In dog 2 left RBF was 444 mL/min/100g and right RBF was 608 mL/min/100g. The apparent diffusion coefficients (ADC) reflected the asymmetry of flow in dog 1 for both spin-echo and turbo-FLASH sequences (RADC/LADC = 1.7) and showed essentially equal flow in dog 2(RADC/LADC = 0.7)