Evaluation of intrarenal oxygenation in mice by BOLD MRI on a 3.0T human whole-body scanner

Abstract

Purpose: To extend observations on intra-renal oxygenation with blood oxygen level-dependent (BOLD) MRI in human and rats to mouse kidneys imaged with a human whole-body scanner. Materials and Methods: Renal BOLD MRI studies were performed on a 3.0T scanner using a multiple gradient-echo (mGRE) sequence with a custom-designed 2.0-cm surface coil to acquire six T2*- weighted images in mice (N = 8) at an in-plane resolution of 156 × 156 μm2. BOLD MRI data were obtained before and after administration of furosemide (10 mg/kg intravenously [i.v.]). Results: The mean weight of eight mice was 24.6 ± 1.0 g. The baseline renal R2* (mean ± standard error [SE]) was 28.6 ± 2.1 seconds-1 in the renal cortex (CO), 35.4 ± 2.2 in the outer medulla (OM), and 21.2 ± 2.1 seconds-1 in the inner medulla (IM). The BOLD response to furosemide (ΔR2*) was 4.1 ± 1.4 in the CO, 10.1 ± 2.1 seconds-1 in the OM, and 3.4 ± 0.8 seconds -1 in the IM in mice. Conclusion: Intrarenal BOLD MR images with sufficiently high resolution can be obtained on a human whole-body scanner when combined with a small receiver coil to allow studies in mice. Both baseline R2* and ΔR2* values following administration of furosemide were consistent with previous experience in humans and rats. © 2007 Wiley-Liss, Inc.