HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Figures Only Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Yang, D. Articles by Ho, C. Search for Related Content PubMed PubMed Citation Articles by Yang, D. Articles by Ho, C.

Normal and Transplanted Rat Kidneys: Diffusion MR Imaging at 7 T¹

¹ From the Department of Biological Sciences, Pittsburgh NMR Center for Biomedical Research, Carnegie Mellon University, 4400 Fifth Ave, Pittsburgh, PA 15213. From the 2002 RSNA scientific assembly. Received November 27, 2002; revision requested January 30, 2003; final revision received October 7; accepted October 20. Supported by contract grants P41EB-001977 and R01EB/AI-00318 from the National Institutes of Health. Address correspondence to C.H. (e-mail: chienho@andrew.cmu.edu).

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, 2004

Index terms: Animals • Experimental study • Kidney, MR, 81.121411, 81.121412, 81.121415, 81.121416, 81.12143 • Kidney, transplantation, 81.4551, 81.4552 • Magnetic resonance (MR), diffusion study, 81.12144

This article has been cited by other articles:

				F. Han, W. Xiao, Y. Xu, J. Wu, Q. Wang, H. Wang, M. Zhang, and J. Chen The significance of BOLD MRI in differentiation between renal transplant rejection and acute tubular necrosis Nephrol. Dial. Transplant., August 1, 2008; 23(8): 2666 - 2672. [Abstract] [Full Text] [PDF]

				H. C. Thoeny, D. Zumstein, S. Simon-Zoula, U. Eisenberger, F. De Keyzer, L. Hofmann, P. Vock, C. Boesch, F. J. Frey, and P. Vermathen Functional Evaluation of Transplanted Kidneys with Diffusion-weighted and BOLD MR Imaging: Initial Experience Radiology, December 1, 2006; 241(3): 812 - 821. [Abstract] [Full Text] [PDF]