Parametric MRI Detects Aristolochic Acid Induced Acute Kidney Injury

Abstract

Exposure to aristolochic acid (AA) is of increased concern due to carcinogenic and nephrotoxic effects, and incidence of aristolochic acid nephropathy (AAN) is increasing. This study characterizes renal alterations during the acute phase of AAN using parametric magnetic resonance imaging (MRI). An AAN and a control group of male Wistar rats received administration of aristolochic acid I (AAI) and polyethylene glycol (PEG), respectively, for six days. Both groups underwent MRI before and 2, 4 and 6 days after AAI or PEG administration. T2 relaxation times and apparent diffusion coefficients (ADCs) were determined for four renal layers. Serum creatinine levels (sCr) and blood urea nitrogen (BUN) were measured. Tubular injury scores (TIS) were evaluated based on histologic findings. Increased T2 values were detected since day 2 in the AAN group, but decreased ADCs and increased sCr levels and BUN were not detected until day 4. Significant linear correlations were observed between T2 of the cortex and the outer stripe of outer medulla and TIS. Our results demonstrate that parametric MRI facilitates early detection of renal injury induced by AAI in a rat model. T2 mapping may be a valuable tool for assessing kidney injury during the acute phase of AAN.

Noninvasive Assessment of Diabetic Kidney Disease With MRI: Hype or Hope?

“…T 2 can be quantified using multiecho (fast) spin‐echo (MESE) variants. Prolongation of T 2 has been reported to be sensitive to increased edema, inflammation, and tubular injury of renal tissues in rodent models of acute kidney injury (AKI) 78,79 . To our knowledge, the literature does not show any study examining the diagnostic or prognostic performance of T 2 in DKD.…”