Guixiang Yang1,2,3, Yingjie Mei2,3, Jian Lü2,3, Quan Tao2,3, Yanqiu Feng2,3, Yikai Xu1,3. 1. Medical Imaging Center, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China. 2. School of Biomedical Engineering, Guangdong Provincial Key Laboratory of Medical Image Processing, Southern Medical University, Guangzhou 510515, China. 3. Key Laboratory of Mental Health of the Ministry of Education, Southern Medical University, Guangzhou 510515, China.
Abstract
OBJECTIVE: To evaluate the changes in renal oxygenation in rats with acute aristolochic acid nephropathy using blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) at 7.0T. METHODS: Wistar rats were randomly divided into AAN group (n=18) and control group (n=6) for intraperitoneal injections of AAI at 40 mg/kg and PEG400, respectively, on a daily basis for 6 consecutive days. All the control rats and 6 rats from AAN group underwent BOLD MRI scan before and at 2, 4, and 6 days after the initial injection for measuring renal cortical and medullary R2* values. At each of the 4 time points, 3 rats in AAN group were sacrificed for histological evaluation; the control rats were examined at 6 days after the initial injection. RESULTS: The cortical and medullary R2* values of the rats in AAN group on days 4 and 6 were significantly higher than those in the control group (P < 0.05). In AAN group, the cortical R2* values showed no obvious changes on day 2 as compared with the baseline values, but increased significantly on day 4 (P < 0.05) and day 6 (P < 0.01); the medullary R2* values increased progressively and were significantly higher than the baseline values on day 4 (P < 0.01) and day 6 (P < 0.01). In the control group, no significant changes were detected in either cortical or medullary R2* values throughout the experiment. CONCLUSIONS: BOLD MRI allows non-invasive measurement of renal oxygenation levels in rats with AAN. The increase of renal cortical and medullary R2* values, and particularly the latter, indicates a lowered renal oxygenation level, which provides potentially useful information for clinical decisions.
OBJECTIVE: To evaluate the changes in renal oxygenation in rats with acute aristolochic acidnephropathy using blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) at 7.0T. METHODS:Wistar rats were randomly divided into AAN group (n=18) and control group (n=6) for intraperitoneal injections of AAI at 40 mg/kg and PEG400, respectively, on a daily basis for 6 consecutive days. All the control rats and 6 rats from AAN group underwent BOLD MRI scan before and at 2, 4, and 6 days after the initial injection for measuring renal cortical and medullary R2* values. At each of the 4 time points, 3 rats in AAN group were sacrificed for histological evaluation; the control rats were examined at 6 days after the initial injection. RESULTS: The cortical and medullary R2* values of the rats in AAN group on days 4 and 6 were significantly higher than those in the control group (P &lt; 0.05). In AAN group, the cortical R2* values showed no obvious changes on day 2 as compared with the baseline values, but increased significantly on day 4 (P &lt; 0.05) and day 6 (P &lt; 0.01); the medullary R2* values increased progressively and were significantly higher than the baseline values on day 4 (P &lt; 0.01) and day 6 (P &lt; 0.01). In the control group, no significant changes were detected in either cortical or medullary R2* values throughout the experiment. CONCLUSIONS: BOLD MRI allows non-invasive measurement of renal oxygenation levels in rats with AAN. The increase of renal cortical and medullary R2* values, and particularly the latter, indicates a lowered renal oxygenation level, which provides potentially useful information for clinical decisions.
Authors: Michael Pedersen; Thomas H Dissing; Jan Mørkenborg; Hans Stødkilde-Jørgensen; Lars H Hansen; Lars B Pedersen; Nicolas Grenier; Jørgen Frøkiaer Journal: Kidney Int Date: 2005-06 Impact factor: 10.612
Authors: Catherine Lebeau; Frédéric D Debelle; Volker M Arlt; Agnieszka Pozdzik; Eric G De Prez; David H Phillips; Monique M Deschodt-Lanckman; Jean-Louis Vanherweghem; Joëlle L Nortier Journal: Nephrol Dial Transplant Date: 2005-08-02 Impact factor: 5.992