Head-to-head comparison of quantitative perfusion parameters derived from DECT, IVIM, and DCE-MRI for renal mass...

Accurate characterization of solid renal masses is essential because management and outcomes differ substantially by histologic subtype. Clear cell renal cell carcinoma (ccRCC), the most common and aggressive RCC subtype, is also the most responsive to targeted anti-angiogenic therapies. Quantitative perfusion imaging may enable a noninvasive "virtual biopsy" approach, but the comparative performance of dual-energy CT (DECT), intravoxel incoherent motion (IVIM), and dynamic contrast-enhanced MRI (DCE-MRI) remains unclear. This study compared perfusion biomarkers from these modalities for differentiating ccRCC from other solid renal masses.

In this prospective single-center study, adults with solid renal masses underwent preoperative DECT, IVIM, and DCE-MRI, with postoperative histopathology as the reference standard. DECT-derived iodine concentration (IC) and iodine ratio (IR), IVIM-derived perfusion fraction (f) and pseudodiffusivity (D*), and DCE-MRI-derived wash-in rate (WIR), wash-out rate (WOR), and area under the time-intensity curve (AUTIC) were evaluated. Diagnostic performance for differentiating ccRCC from other solid renal masses was assessed using receiver operating characteristic (ROC) analysis and multivariable logistic regression.

Thirty-three patients (mean age, 49.8 ± 11.9 years; 21 men) were included. Compared with other solid renal masses, ccRCC demonstrated significantly higher IC and IR (p < 0.02) and higher AUTIC and WIR (p < 0.05). IVIM parameters did not differ significantly (p > 0.05). IC achieved the highest diagnostic performance across readers (AUC, 0.79-0.83). After exclusion of benign tumors, IC demonstrated excellent discrimination (AUC, 0.96; 95% CI, 0.89-1.00). Multivariable models did not improve performance over the best individual parameter.

DECT and DCE-MRI perfusion biomarkers showed comparable performance for differentiating ccRCC from other solid renal masses, whereas IVIM provided limited diagnostic value. The lack of incremental benefit from multiparametric modeling suggests that DECT-derived iodine concentration alone may be sufficient for clinical virtual biopsy workflows, particularly when MRI is unavailable or contraindicated.