The Differentiation Characterization Of Contrast-enhanced Ultrasound And Contrast-enhanced CT In Liver Metastases

Objective：To investigate the perfusion features of liver metastases with contrast-enhanced ultrasound(ECUS), compare with contrast-enhanced computed tomography(CECT) in order to explore theclinical value of CEUS in liver metastases.Methods：12patients (20metastases) with liver metastases were examined with CEUS and CECT. TheCEUS examinations were performed with IU22, Philips. Patients were asked to be on an emptystomach with supine position, exposing upper abdomen. Firstly, the entire liver was scanned withconventional ultrasound. The location, size, number, boundary and echo of metastases wereobserved. Secondly, the blood flow of the lesions was observed with Color Doppler FlowImaging(CDFI). Finally, select the best section and switch to CEUS, MI:0.06-0.08, the contrastagent: SonoVue. SonoVue suspension was injected intravenously as a bolus of2.4ml whilebeginning record, followed by a flush of5ml0.9%saline solution. The enhanced pattern andenhanced level of lesions was observed by two doctors, especially early arterial phase(0～25s),compared with CECT. Time-intensity curve(TIC) was analysised, and recorded arriving time(AT)and peaking time(PT).All patients received the examination with CECT(16-slice, GE), slice thickness:5mm, thecontrast agent: Iohexol, injecting velocity:3ml/s.The arterial phase scanning began at25s afterIohexol was injected, the portal venous phase sequence scan at70s, and the balance phase sequencewas obtained at120～180s. Patients were told to hold his breath for a while before scanning. Thelocation, form, size, number, enhanced pattern and level of metastases were observed and stored.According to enhanced pattern of lesion in arterial phase, the categorization patterns weredivided into3classes:+1: diffuse enhancement,0: ring enhancement or inhomogeneous enhance-ment,-1: no-enhancement or spot-enhancement.All the datas obtained were analyzed by SPSS13.0software, χ2test was used to compare thedifference between count datas, P＜0.05was considered as statistically significant difference.Results：Among20metastases of12patients, CEUS arterial phase:11(55%) showed diffuseenhancement,7(35%) showed ring enhancement,2(10%) showed inhomogeneous enhancement, noone showed no-enhancement or spot-enhancement.+1grade:11(55%),0grade:9(45%),-1grade:0(0%). CECT arterial phase:1(5%) showed low-grade diffuse enhancement,11(55%) showed ringenhancement,2(10%) showed inhomogeneous enhancement,6(30%) showed no-enhancement.+1 grade:1(5%),0grade:13(65%),-1grade:6(30%). The conclusion of χ2test of CEUS and CECTwas P＜0.005, and considered as statistically significant difference.Conclusion：1.The enhancement feature of most liver metastases was diffuse enhancement with CEUS inarterial phase, part showed ring enhancement or inhomogeneous enhancement.2.CEUS is better than CECT when observing the perfusion feature in early arterial phase forliver metastases. CEUS is great helpful in the clinical diagnosis and treatment of the patientssuspected of liver metastases of lack blood supply with CECT, especially only one lesion.