Intravoxel incoherent motion imaging of the kidney: The application in patients with hyperuricemia

BACKGROUND: Hyperuricemia is an independent risk factor for onset and progression of kidney disease. However, there remains a lack of a reliable and noninvasive biomarker to identify and monitor the changes of renal function in patients with hyperuricemia. PURPOSE: To assess the utility of intravoxel incoherent motion (IVIM) parameters in identifying the early changes of renal function in patients with hyperuricemia. STUDY TYPE: Retrospective case-control study. POPULATION: Eighty-four male participants, including asymptomatic hyperuricemia (AH, 27 cases), gouty arthritis (GA, 31 cases), and 26 age-matched healthy controls. FIELD STRENGTH/SEQUENCE: 3.0T; intravoxel incoherent motion (IVIM). ASSESSMENT: Differences in the IVIM parameters among the three groups were assessed. Pure molecular diffusion (D value); perfusion-related diffusion (D* value); pseudodiffusion fraction (f value); apparent diffusion coefficient (ADC value); estimated glomerular filtration rate (eGFR). Also, they were correlated with eGFR. STATISTICAL TESTS: method, and Pearson correlation analysis. RESULTS: The D values in renal cortex and medulla significantly decreased from the control, AH to GA groups (P < 0.05). The GA patients had a significantly lower cortical f value than the controls and AH patients (P < 0.05). The medullary f values in the AH and GA patients were significantly lower than that in the controls (P < 0.05). Also, the cortical and medullary ADC values had similar results across the three groups (P < 0.05), except for the comparison between the AH and GA groups (P = 0.668, P = 0.111, respectively). No significant correlation was found between any IVIM parameters with eGFR. DATA CONCLUSION: IVIM imaging may be helpful for detecting the early changes of renal function induced by hyperuricemia. The D value could be the most sensitive IVIM-derived parameter in the assessment of renal function in patients with hyperuricemia in this study. LEVEL OF EVIDENCE: 3 Technical Efficacy Stage: 3 J. Magn. Reson. Imaging 2020;51:833-840.