Evaluating renal function with intravoxel incoherent motion in a unilateral ureteral obstruction model

Patients with renal injury are at increased risk of exacerbating kidney damage from contrast-enhanced radiological examinations. Therefore, a noninvasive and sustainable method for assessing renal function without contrast agents is imperative. This study evaluates the effectiveness of intravoxel incoherent motion-derived parameters in assessing renal function, comparing them to findings from single-photon emission computed tomography in rat models.

This study involved 2 groups of rats. The first group underwent scans and biopsies on days 0, 3, 7, 10, and 14 after obstruction, whereas the second group was subjected to unilateral ureteral obstruction on the same days. Rats in the second group were also scanned on days 7 and 14 after obstruction release, with histopathological analyses performed on day 14 after recanalization. Parameters measured included the apparent diffusion coefficient, pure molecular diffusion, pseudodiffusion, perfusion fraction, and glomerular filtration rate (GFR) using both intravoxel incoherent motion and single-photon emission computed tomography. Data from each time point were analyzed using 1-way analysis of variance for multiple groups, and Pearson correlation analysis was used to evaluate the relationships between these parameters and GFR.

Glomerular filtration rate showed positive correlations with apparent diffusion coefficient and pure molecular diffusion (p < 0.05). Additionally, cortical f demonstrated a significant positive correlation with GFR (r = 0.841, p < 0.05).

Intravoxel incoherent motion effectively captures changes in GFR during renal obstruction and recanalization. Notably, cortical f proves to be a promising indicator for assessing GFR.