Functional evaluation of normothermic ischemia and reperfusion injury in dog kidney by combining MR diffusion‐weighted imaging and Gd‐DTPA enhanced first‐pass perfusion

Abstract

Purpose:To evaluate functional alterations of renal ischemia and reperfusion injury using MR diffusion-weighted imaging and dynamic perfusion imaging. Materials and Methods:Twelve dogs were randomly divided into four groups. Animal renal ischemia was respectively induced for 30 (group 1), 60 (group 2), 90 (group 3), and 120 (group 4) minutes by left renal artery ligation under anesthesia. Using a 1.5 T MR system, true-FISP, TSE, EPI, and DWI sequences were acquired in five different periods; specifically, pre-ischemia, onset-ischemia, late ischemia, onset-reperfusion, and post-reperfusion. Moreover, a turbo-FLASH sequence (TR/TE/TI/FA ϭ 5.8/3.2/ 400 msec/10°) with a temporal resolution of 1.16 seconds was acquired. Signal intensity (SI) was measured in the cortex, outer medulla, and inner medulla of kidney. Apparent diffusion coefficient (ADC) values were calculated, and SI was plotted as a function of time. Results:In all animals, significant SI changes of the left kidney on T2/T2*WI were detected following ischemia-reperfusion insult compared to corresponding values of the right kidney. Following ligation, the ADC values decreased in all layers of the left kidney. Immediately after the release of ligation, ADC values in both outer and inner medulla of the left kidney remained lower than those of the right kidney in those animals which were induced with renal ischemia for 60, 90, and 120 minutes. In all groups, a uniphasic enhancement pattern was observed in the outer and inner medulla of the left kidney, accompanied by a decrease of the area under the curve. Conclusion:Our results suggest that MR diffusionweighted imaging and dynamic perfusion imaging are useful in identifying renal dysfunction following normothermic ischemia and reperfusion injury.

Extracranial applications of diffusion-weighted magnetic resonance imaging

“…Diabetic rats with cellular edema showed significantly lower ADC values in the kidneys than the control group; the results correlated with histopathological findings [26]. A decrease in ADC in dog kidneys following ischemia induced by renal artery ligation has been described [27].…”

Functional MRI of the kidney: tools for translational studies of pathophysiology of renal disease

“…However, there are several other techniques that have been demonstrated as potential fMRI methods with specific applications to the kidney. These include diffusion measurements in the kidney (79,94,122,135), pH measurements (119), and, more recently, sodium MRI (84). While diffusion measurements certainly provide opportunities for tissue characterization, it is not quite clear what the measured values represent in terms of the functional status of the kidney.…”

Time course study on the effects of iodinated contrast medium on intrarenal water transport function using diffusion‐weighted MRI

“…Moreover, the water diffusion between intra and extra-cellular can be estimated by the apparent diffusion coefficient (ADC) (11). In renal parenchyma, the value of ADC mainly depends on the intra-and extra-cellular components fraction, ambient temperature, membrane permeability and capillary perfusion (12)(13)(14). Thus, DW-MRI can quantify alterations in water content as well as water exchange rate between intra and extra-cellular aspects of the kidney.…”