Diffusion kurtosis versus diffusion-weighted magnetic resonance imaging in differentiating clear cell renal cell carcinoma and renal angiomyolipoma with minimal fat: a comparative study.

Purpose: To quantitatively compare the diagnostic values of conventional diffusion-weighted imaging and diffusion kurtosis imaging (DKI) in differentiating clear cell renal cell carcinoma (ccRCC) and renal angiomyolipoma with minimal fat (RAMF).

Methods: Sixty-eight patients with ccRCC and 18 patients with RAMF were retrospectively studied. For DKI and apparent diffusion coefficient (ADC), respiratory-triggered echo-planar imaging sequences were acquired in the axial plane (three b-values: 0, 1000, 2000 s/mm²; one b-value: 2000 s/mm²). Mean diffusivity (MD), fractional anisotropy (FA), mean kurtosis (MK), kurtosis anisotropy (KA), radial kurtosis (RK), and ADC were evaluated. The diagnostic efficacy of various diffusion parameters in predicting ccRCC and RAMF was compared.

Results: The ADC and MD values of ccRCCs were higher than those of RAMFs (P < 0.05), whereas comparable FA, MK, and KA values were observed between ccRCCs and RAMFs (P > 0.05). Moreover, the RK values of RAMFs were higher than those of ccRCCs (P < 0.05). Receiver operating characteristic (ROC) curve analyses showed that MD values had the highest diagnostic efficacy in differentiating ccRCCs from RAMFs. In pairwise comparisons of ROC curves and diagnostic efficacy, DKI parameters demonstrated better diagnostic accuracy than ADC in differentiating between ccRCCs and RAMFs (P < 0.05).

Conclusion: DKI analysis demonstrates superior performance than ADC analysis in differentiating ccRCC and RAMF.

Clinical significance: DKI technology may serve as an additional non-invasive biomarker for the differential diagnosis of renal tumor types.