Abstract: Objective To investigate the relationship between the contrastenhanced ultrasound perfusion characteristics of small hepatocellular carcinoma（SHCC） and pathology and its clinical value.
Methods Three hundred and sixtynine cases liver focus lesions detected by conventional ultrasound were examined by contrastenhanced ultrasound（CEUS）. The CEUS imaging characteristics and pathological results of SHCC were analyzed and compared. Results（1） Compared with pathological results of 254 malignant lesions and 124 benign lesions，the sensitivity of CEUS in diagnosis of SHCC was 98.8％（242／245）， the specificity was 92.7％（115／124）， the accuracy was 96.7％（357／369）， Jorden index was 0.92， the positive likelihood ratio was 13.7， negative likelihood ratio was 0.013.（2） The CEUS characteristics of SHCC were rapid enhancement in early artery period， rapid clearance in late artery period or early portal period， that was characterized by fast enhancement and clearance. The enhancement pattern of fast in and out was accounted for 87.2％（219／251） in malignant tumor lesions compared with 1.7％（2／118） in benign lesions. The difference has statistical significance（P＜0.05）.（3） The differences of CEUS enhancement time and peak time in different pathological differentiation of SHCC were no statistically significant（P＞0.05）， but the differences of time to clarify were statistically significant（P＜0.05）. Clearance time of the high differentiation，moderate differentiation and low differentiation of SHCC was（102.4±2.36）s，（76.02±3.88）s，（49.40±4.95）s， respectively. The clearance time in high differentiation of SHCC was significantly longer than that of the low differentiation degree of SHCC（P＜0.05）.
ConclusionCEUS has important clinical value in the diagnosis of SHCC and the evaluation of pathological differentiation degree.