The value of superb microvascular imaging in differentiating benign renal mass from malignant renal tumor: a retrospective study

OBJECTIVE: This study is to evaluate the value of superb microvascular imaging (SMI) in assessing renal tumour vascularity and in differentiating benign from malignant renal tumours. METHODS: Patients with pathologically confirmed renal mass who underwent colour Doppler flow imaging (CDFI) and SMI examination between October 2016 and March 2017 were retrospectively analysed. Patients were classified into benign renal mass group and malignant tumour group according to their pathological results. The vascularity, vascular distribution and vessel morphology obtained from the two scanning methods were analysed and compared between the two groups. RESULTS: 53 patients with renal tumour were enrolled into the study, including 11 cases of benign renal tumours and 42 cases of malignant ones. SMI showed significant difference in vascularity between the two groups; CDFI showed no statistical difference. Compared with CDFI, SMI showed significantly higher grade in malignant tumour (p < 0.001), and no significant difference (p = 0.421) in benign mass. According to CDFI, there is no statistical difference in vascular distribution and vessel morphology (p = 0.432, p = 0.122) between the two groups, while SMI method showed significant difference (p < 0.05) between the two groups. SMI was significantly more sensitive and accurate than CDFI. CONCLUSION: Comparing with CDFI, SMI could effectively detect vascularity, vascular characteristics and distribution and annular blood flow in renal tumour. SMI appears more sensitive and precise in distinguishing benign renal mass from malignant tumour. Advances in knowledge: SMI seems potentially valuable in evaluating renal tumour vascularity and in differentiating benign from malignant renal tumours.