Role of Contrast-Enhanced Ultrasound With the Enhancement Pattern and Qualitative Analysis for Differentiating Hypovascular Solid Renal Lesions.

ABSTRACT

OBJECTIVE: The aim of the work described here was to explore the clinical value of contrast-enhanced ultrasound (CEUS) with the enhancement pattern and qualitative analysis in distinguishing different types of hypovascular solid renal lesions. METHODS: A total of 140 patients with 140 renal tumors (all diagnosed by pathology), which manifested hypo-enhancement on CEUS, were included in this study. We compared conventional ultrasound (US) and CEUS features in five common hypovascular renal tumors, including renal angiomyolipoma (RAML), clear cell renal cell carcinoma (ccRCC), renal pelvic urothelial carcinoma (RPUC), papillary renal cell carcinoma (pRCC) and chromophobe renal cell carcinoma (chRCC). The diagnostic value of conventional US and qualitative parameters of CEUS for differentiating hypovascular solid renal lesions were evaluated. RESULTS: The mean age of patients with a benign renal lesion was younger than that of patients with a malignant renal lesion (p < 0.05). Echogenicity and qualitative parameters such as wash-out, perfusion defects and perilesional rim-like enhancement (PRE) in the two groups differed significantly (all p values <0.05). Benign renal lesions exhibited mainly slow wash-out, whereas malignant renal lesions exhibited predominantly fast wash-out on CEUS (p < 0.05). There were significant differences in echogenicity, such as between RAML and ccRCC, between RAML and RPUC and between RAML and pRCC (all p values <0.05). The rates of appearance of perfusion defect in ccRCC (48%, 13/27) and pRCC (53%, 10/19) were significantly higher than the rate in RAML (14%, 6/43) (p < 0.05). The rates of appearance of PRE in ccRCC (15%, 4/27), pRCC (26%, 5/19) and chRCC (24%,4/17) were significantly higher than the rate in RAML (9%, 4/43) (p < 0.05). CONCLUSION: CEUS with the enhancement pattern and qualitative analysis may be helpful in distinguishing malignant from benign hypovascular renal lesions.