DTI for the assessment of disease stage in patients with glomerulonephritis--correlation with renal histology

Abstract

Objectives: To investigate whether DTI allows assessment of renal impairment and pathology in patients with chronic glomerulonephritis.

Materials and methods: Seventy-five patients and 20 healthy volunteers were enrolled in this study. Renal function and kidney biopsies were evaluated. For DTI, a respiratory-triggered coronal EPI sequence was performed (TR, 1400 ms; TE, 76 ms; diffusion direction, 6; NEX, 4; b values, 0 and 600 s/mm2; slices thickness, 6 mm, with no intersection gap). Renal ADC and FA values were calculated and compared between the groups. Correlations between ADC/FA and histopathology were evaluated.

Results: ADC values decreased with increased stages. ADC differences in renal parenchyma at different disease stages were found, with the exception of the control group compared with stage 1 patients; similar results were obtained for FA. ADC values in the cortex and medulla in stage 1-3 patients were both statistically different, similar to the FA values. A significant negative correlation was found between the percentage of glomerulosclerosis and FA in the renal cortex (r = -0.74), similar to the degree of tubulointerstitial fibrosis with FA in the medulla (r = -0.76).

Conclusions: ADC and FA values are correlated with the degree of renal impairment, the percentage of glomerulosclerosis, and area of interstitial fibrosis.

Key points: • DTI can be used to assess renal function impairment in patients with chronic glomerulonephritis. • ADC and FA values were correlated with tubulointerstitial fibrosis and glomerulosclerosis. • Identification of renal impairment is helpful for timely treatment. • DTI can be used for non-invasive assessment of renal pathology.