Objective  To investigate the application value of superb microvascular imaging (SMI) in benign and malignant renal lesions by comparing with power Doppler imaging (PDI).

  Methods  Retrospective analysis was performed on 48 cases of renal lesions in 47 patients screened via PDI and SMI at Tianjin Medical University Cancer Institute and Hospital. A total of 10 and 38 cases of benign and malignant lesions were identified, respectively. We compared the diagnostic efficiency between the two methods by determining blood flow grade, distribution pattern, morphology, and ring-like blood flow.

  Results  Statistically significant differences in ring-like blood flow (P < 0.05) but not in blood flow grade, distribution pattern, and morphology (P > 0.05) were observed between benign and malignant renal tumors as detected by PDI. In SMI, statistically significant differences in blood flow grade, distribution pattern, morphology, and ring-like blood flow were identified between benign and malignant renal tumors (P < 0.05). The sensitivity, specificity, and area under the receiver operating characteristic curve of PDI and SMI were 71.05%, 70.00%, and 0.705 and 89.47%, 90.00%, and 0.897, respectively. Significance in diagnostic efficacy between PDI and SMI was detected (P=0.025).

  Conclusion  Compared with PDI, SMI can more accurately describe blood flow grade, distribution pattern, morphology, and ring-like blood. Thus, SMI can improve the accuracy of differential diagnosis of benign and malignant renal tumors.