Measurement of renal vein blood flow in rats by high-field magnetic resonance

Measurement of renal vein blood flow in rats by high-field magnetic resonance. The aim of the present study was to examine whether magnetic resonance imaging (MRI) based method for non-invasive in vivo measurement of vein blood flow in rats could be used to estimate renal blood flow (RBF). Measurements were performed using a high-field (7 Tesla) MRI scanner with a short echo time phase contrast velocity measurement pulse sequence. The method was evaluated in vitro by flow measurements in an acrylic pipe and in vivo by recording left renal vein blood flow in normal and unilaterally nephrectomized rats. In a subset of animals RBF was measured by a direct method using 14 C-tetraethylammoniumbromide. In vitro a high accuracy was found between applied and MRI measured flow rates in the range from 0.5 to 33ml/min ( r = 0.997; P In vivo the MRI measured left renal vein blood flow was 70% higher in unilaterally nephrectomized animals compared to control animals (3.4 ± 0.4ml/min/ 100g body wt vs. 2.0 ± 0.1ml/min/100g body wt, P P = 0.05). In addition, the left kidney volume was recorded by MRI with an increase amounting to 40% (1.18 ± 0.05ml vs. 0.84 ± 0.02ml; P r = 0.91; P