Characteristics of parametric imaging of contrast-enhanced ultrasound for hepatic hemangioma

Objective To investigate the characteristics of parametric imaging of contrast-enhanced ultrasound (CEUS) in evaluating hepatic hemangioma. Methods Totally 42 cases of patients with hemangioma were selected from October 2013 to April 2015 in the Tenth People's Hospital of Tongji University. Thirty-eight cases were confirmed by CT and magnetic resonance imaging (MRI), and 4 cases were confirmed by surgery pathology for cavernous hemangioma. SonoLiver CAP software was used to quantitatively analyze the CEUS and calculate dynamic vascular imaging model parameters (DVP) based on the enhancement difference between lesions and surrounding normal liver parenchyma. The peak intensity (Imax), the rise time (RT), time to peak (TTP), mean transit time (mTT), perfusion index (PI) and DVP curve of hemangioma and surrounding parenchyma were analyzed. T test was used to compare the differences of Imax, RT, TTP, mTT and PI among the large liver hemangioma, small liver hemangioma and surrounding normal liver parenchyma, between large liver hemangioma and small liver hemangioma, and between the edge and central part of liver hemangioma, respectively. Results Imax and PI in both large hemangioma and small hemangioma were higher than that in normal liver parenchyma; RT, TTP and mTT were shorter in the surrounding normal liver parenchyma, and the differences were statistically significant. Imax in large liver hemangioma was higher than that in small hemangioma, and the difference was statistically significant. The difference of RT, TTP, mTT and PI between large hemangioma and small hemangioma were not statistically significant. Imax in central part was higher than that in the edge part of liver hemangioma. RT, TTP in central part were also longer than that in edge part, and the difference had statistical significance. mTT and PI in both large and small hemangioma had no significant difference. DVP curves and DVP parameter figures of liver hemangioma can be divided into three types: type Ⅰ, positive model with gradual washout; type Ⅱ, positive model with no washout; type Ⅲ, negative model. For DVP curves and DVP parameter , type Ⅰ, type Ⅱ and type Ⅲ respectively had 16 cases (16/42, 38.1%), 20 cases (20/42, 47.6%), 6 cases (6/42, 14.3%) and 15 cases (15/42, 35.7%), 10 cases (10/42, 23.8%), 17 cases (17/42, 40.5%). Conclusions TTP and mTT of hemangiomas was shorter than the surrounding liver parenchyma by using contrast-enhanced ultrasound imaging parameters. The Imax and PI in large hemangioma was higher than that in small hemangioma. The RT and TTP in hemangioma edges was faster than that in central parts. The difference of blood perfusion in the liver hemangioma and surrounding liver parenchyma could be shown by DVP curve. Key words: Ultrasonography; Contrast media; Liver; Hemangioma