Normal and Transplanted Rat Kidneys: Diffusion MR Imaging at 7 T
- 1 June 2004
- journal article
- Published by Radiological Society of North America (RSNA) in Radiology
- Vol. 231 (3), 702-709
- https://doi.org/10.1148/radiol.2313021587
Abstract
PURPOSE: To investigate the feasibility of obtaining reproducible apparent diffusion coefficient (ADC) maps of normal rat kidneys by using respiratory-triggered spin-echo diffusion-weighted magnetic resonance (MR) imaging, to investigate the sensitivity of ADC maps in the evaluation of renal blood flow, and to use this technique to monitor acute graft rejection in transplanted rat kidneys. MATERIALS AND METHODS: Spin-echo diffusion-weighted MR imaging measurements were performed in 20 normal rats and nine rats that had undergone transplantation (six rats had received allografts; three had received isografts) at 7 T. To evaluate the effect of alteration in blood flow and water transport function, angiotensin II was infused in six normal rats and a series of spin-echo diffusion-weighted MR images was obtained at five time points. Transplanted kidneys were monitored by obtaining spin-echo diffusion-weighted MR images and gradient-echo MR images every 2 hours for 8 hours on postoperative day 4. Statistical analysis was performed with repeated-measures multivariate analysis of variance and the paired t test. RESULTS: No significant differences in ADC values were observed between right and left kidneys in all three orthogonal directions; however, a small difference was observed between the cortex and medulla. ADC values in the cephalocaudal and mediolateral directions were higher than those in the anteroposterior direction (P < .01 for all). ADC values in the cortex and medulla decreased significantly (by >35%, P < .01) during angiotensin II–induced reduction in renal blood flow. No significant signal intensity change was observed between native and transplanted kidneys on gradient-echo MR images. Allografts exhibited decreased ADC values (P < .01) and isografts exhibited similar ADC values compared with native kidneys. CONCLUSION: These findings suggest that reproducible renal ADC maps can be obtained in rats by using spin-echo diffusion-weighted MR imaging at 7 T. Spin-echo diffusion-weighted MR imaging may have potential as a noninvasive tool for monitoring early graft rejection after kidney transplantation. © RSNA, 2004This publication has 24 references indexed in Scilit:
- Diffusion tensor MRI of the human kidneyJournal of Magnetic Resonance Imaging, 2001
- Hemodynamic Effect of Iodinated High-Viscosity Contrast Medium in the Rat KidneyInvestigative Radiology, 2000
- Measurement of the apparent diffusion coefficient in diffuse renal disease by diffusion-weighted echo-planar MR imagingJournal of Magnetic Resonance Imaging, 1999
- Diffusion Coefficients in Abdominal Organs and Hepatic Lesions: Evaluation with Intravoxel Incoherent Motion Echo-planar MR ImagingRadiology, 1999
- Feasibility of MR Diffusion Studies in the KidneyJournal of Magnetic Resonance Imaging, 1995
- Functional imaging of the kidney by means of measurement of the apparent diffusion coefficient.Radiology, 1994
- Magnetic resonance diffusion/perfusion phantom experimentsMagnetic Resonance in Medicine, 1991
- Analysis of T2 limitations and off‐resonance effects on spatial resolution and artifacts in echo‐planar imagingMagnetic Resonance in Medicine, 1990
- Separation of diffusion and perfusion in intravoxel incoherent motion MR imaging.Radiology, 1988
- MR imaging of intravoxel incoherent motions: application to diffusion and perfusion in neurologic disorders.Radiology, 1986