Chronic kidney disease: pathological and functional assessment with diffusion tensor imaging at 3T MR

Objective Our objective was to evaluate pathological and functional changes in chronic kidney disease (CKD) using diffusion tensor imaging (DTI) at 3 T. Methods There were fifty-one patients with CKD who required biopsy and 19 healthy volunteers who were examined using DTI at 3 T. The mean values of fractional anisotropy (FA) and the apparent diffusion coefficient (ADC) were obtained from the renal parenchyma (cortex and medulla). Correlations between imaging results and the estimated glomerular filtration rate (eGFR), as well as pathological damage (glomerular lesion and tubulointerstitial injury), were evaluated. Results The renal cortical FA was significantly lower than the medullary in both normal and affected kidneys (p<0.001). The parenchymal FA was significantly lower in patients than healthy controls, regardless of whether eGFR was reduced. There were positive correlations between eGFR and FA (cortex, r=0.689, p=0.000; and medulla, r=0.696, p=0.000), and between eGFR and ADC (cortex, r=0.310, p=0.017; and medulla, r=0.356, p=0.010). Negative correlations were found between FA and the glomerular lesion (cortex, r=0.499, p=0.000; and medulla, r=-0.530, p=0.000), and between FA and tubulointerstitial injury (cortex, r=-0.631, p=0.000; and medulla, r=-0.724, p=0.000). Conclusion DTI is valuable for noninvasive assessment of renal function and pathology in patients with CKD. A decrease in FA could identify the glomerular lesions, tubulointerstitial injuries, and eGFR.