Diagnostic value of pseudocapsule ring hyperenhancement in contrast-enhanced ultrasound in renal focal lesions

Object To investigate the diagnostic value of pseudocapsule ring hyperenhancement in contrast-enhanced ultrasound (CEUS) of focal renal lesions. Method Ninety eligible patients admitted were selected as the study subjects. The incidence rate of annular hyperenhancement in different benign and malignant focal lesions during angiography and the shape of annular enhancement were counted. The correlation between the occurrence of benign and malignant renal tumors and annular hyperenhancement and unenhanced areas was also analyzed. Results Capsule enhancement was observed in 56 cases, including 50 cases of malignant tumors (89.3%, 50/56) and 6 cases of benign tumors (10.7%, 6/56). Pearson correlation analysis showed that renal malignancy was positively associated with the occurrence of pseudocapsule ring hyperenhancement ( γ = 0.489, P < 0.001). Benign and malignant renal tumors were positively correlated with the occurrence of non-enhancing areas ( γ = 0.215, P = 0.042). The thickness and peak intensity of pseudocapsule ring enhancement in renal malignant tumors were significantly higher than those in benign tumors (all P < 0.001), while the time to peak was significantly lower than that in benign tumors ( P < 0.001). The results of receiver operating characteristic (ROC) curve showed that the ring enhancement thickness, time to peak, and area under ROC curve of peak intensity of tumor reached more than 0.9. Conclusion In CEUS, the pseudocapsule of focal renal lesions is a characteristic feature of renal malignant tumors, which can be used as a differential basis for benign and malignant tumors to improve the accuracy of benign and malignant renal tumors.