Diagnostic Performance of Multiphase Multidetector CT in the Differentiation of Renal Cell Carcinoma (RCC) Subtypes

Purpose: This study aimed to determine the applicability of quantitative multiphase multidetector computed tomography (MDCT) enhancement parameters for diagnosing renal cell carcinoma (RCC) subtypes and evaluate their discriminating capability.Methods: This retrospective study included 72 patients with histopathologically confirmed RCC from 2009 to 2013. The patients included 58 with clear-cell RCC (ccRCC), 7 with papillary RCC, and 7 with chromophobe RCC. Patients underwent multiphase MDCT for quantitative enhancement parameter calculations, including corticomedullary and excretory enhancement difference (ΔHU) and standardized enhancement ratios. Cutoff values for subtypes were determined using receiver operating characteristic (ROC) curve analysis.Results: Corticomedullary ΔHU parameters showed best performance across all phases. The highest sensitivity, specificity, and accuracy (sensitivity 93%, specificity 100%, accuracy 94%) were associated with a ΔHU cutoff of > 47 HU. A standardized corticomedullary enhancement ratio of > 0.31 yielded 93% sensitivity, 93% specificity, and 93% accuracy. The washout enhancement pattern showed lower performance, with 79% accuracy and 92% specificity. The corticomedullary phase performed significantly better than the excretory phase (p