Application of superb microvascular imaging in focal liver lesions

Objective: To investigate the ability of superb-microvascular imaging (SMI) to detect microvascular characteristics of focal liver lesions (FLLs) and analyze the relationship between vascular index (VI) and microvascular density (MVD) and Ki-67 levels. Methods: The imaging data of patients diagnosed as FLLs at Tianjin Medical University Cancer Hospital in 2018 were collected. A total of 166 FLLs patients were divided into non-hepatocellular liver cancer (non-HCC group, 96) and HCC group (70), respectively. The whole group of patients were subjected to color Doppler blood flow imaging (CDFI) and SMI examination. The patient's Adler's semi-quantitative grading (0 to 3 levels) and vascular morphological characteristics (a-f type) were analyzed. The receiver operating characteristic (ROC) curve was used to evaluate the detection ability of HCC with SMI and CDFI blood flow characteristics, The Pearson correlation analysis was used to evaluate the correlation between HCC patients VI and MVD and the Spearman correlation analysis was used to evaluate the correlation between VI and Ki-67. Results: In HCC group, SMI detected 50 cases of high-level blood flow (Adler's semi-quantitative grade 2 to 3) patients, higher than 22 cases of CDFI (P=0.033). In HCC group, SMI detected 52 cases of blood-rich mode (e, f type), higher than 18 cases of CDFI (P<0.001). In non-HCC group, the difference of blood flow characteristics detection between CDFI and SMI was not statistically significant. In HCC group, SMI detected 52 cases of rich blood supply patterns, which was higher than 14 cases of non-HCC group (P<0.001). The area under the ROC curve of SMI was 0.760 (sensitivity was 74.3%, specificity was 85.4%), and the SMI rich blood supply mode had the best diagnostic effect on HCC based on the blood-rich mode as the HCC diagnostic standard. In HCC group, VI was positively correlated with MVD and Ki-67 (r=0.698 and r=0.669, respectively, P<0.05). Conclusions: SMI has better detection ability than CDFI for HCC microvascular characteristics, HCC has more blood-rich mode than non-HCC. In HCC, VI is positively correlated with MVD and Ki-67 expression levels.