Differentiation of Fat‐Poor Renal Angiomyolipoma From Clear Cell Renal Cell Carcinoma: Diagnostic Performance of a Novel Type of Color Contrast Enhanced Ultrasound

BACKGROUND: The similar imaging characteristics of renal angiomyolipoma without visible fat (RAML.wvf) and clear cell renal cell carcinoma (ccRCC) are notable. Color Parameter Imaging (CPI) has emerged as an advanced contrast-enhanced ultrasound (CEUS) analysis tool that quantifies temporal perfusion dynamics. OBJECTIVE: Evaluate the diagnostic value of CPI in distinguishing AML.wovf from ccRCC. METHODS: In this prospective study, 88 patients (35 with AML and 53 with ccRCC) underwent CEUS and CPI. Junior and senior radiologists independently analyzed the CEUS and CPI images. Three diagnostic approaches were compared: (1) CPI alone, (2) CEUS alone, and (3) CEUS combined with CPI. The diagnostic sensitivity, specificity, accuracy, and receiver operating characteristic (ROC) curves of resident and staff radiologists were analyzed. RESULTS: The CPI features of ccRCC and AML.wovf analyzed by the junior and senior radiologist groups showed significant differences: the mosaic sign and the Cold sign (both p < 0.001) were more indicative of AML.wovf, whereas the Warm sign was more suggestive of ccRCC (both p < 0.05). The area under the curve (AUC) for the combined CEUS+CPI diagnosis in the junior radiologist group was higher than that for CEUS alone (p = 0.012). Regarding diagnostic confidence between the two radiologist groups, the proportion of uncertain cases in the CPI group was significantly lower than in the CEUS group for both the senior radiologist group and the junior radiologist group (both p < 0.05). CONCLUSION: CPI technology can enhance the diagnostic performance of contrast-enhanced ultrasound in differentiating ccRCC from AML.wovf, particularly offering an advantage in improving the diagnostic accuracy of junior radiologists.