The Value Of Contrast-enhanced Ultrasound In Diagnosis Of Liver Metastases

ObjectiveThe purposes of this study were to investigate the enhancement appearance of contrast-enhanced ultrasound (CEUS) for the liver metastases; to find if there are differences of tumor's sizes between pre-CEUS and post-CEUS; to determine the value of CEUS in diagnosis of the liver metastases.MethodsTwenty-one patients with liver metastases hospitalized in Shengjing Hospital, China Medical University between October 2008 and December 2009, were performed both conventional US and CEUS examination.LOGIQ 9 (GE, American) with probe C2-4MHz was used in the study. The injected contrast agent was SonoVue (Brocca, Milan, Italy). Firstly, all lesions were scanned with conventional modalities, an interested lesion and the best imaging section were selected. Secondly, all patients received a bolus injection of SonoVue by cubital vein. Then started the Code PI mode of the device with low mechanical index (MI) 0.08-0.10. The sizes of the lesions at conventional modalities and CEUS (at delayed phase) during the examination were measured and recorded. The whole processes of dynamic images were recorded for the following analysis with time-intensity curve (TIC) soft. The parameters of TIC such as arrival time (AT), basic intensity, time to peak(TTP), peak intensity (PI), fill-in pattern were observed and recorded. All statistical analysis was performed by using the SPSS 11.5 statistical package. A P-value< 0.05 was considered to be statistical significance.Results1,All lesions were enhancement at the arterial phase, including 12 lesions (44.4%) showed hyper-enhancement; 11 lesions (40.8%) showed circular enhancement; 2 lesions (7.4%) showed heterogeneous enhancement and 2 lesions (7.4%) showed iso-enhancement. Twenty-five lesions (92.6%) showed hypo-enhancement and 2 lesions (7.4%) showed iso-enhancement during portal-venous phase and delayed phase.2,TIC curve shape mainly showed sharply fast ascent and descent.3,At delayed phase of CEUS, five patients showed more lesions than conventional ultrasound.4,The average size of lesions at the post-CEUS was a little bigger than that of the pre-CEUS. But there were no statistical significance between the pre-CEUS and post-CEUS in sizes of the lesions (P>0.05).Conclusions1,The liver metastases mainly showed hyper-enhancement or circular enhancement at the arterial phase, and hypo-enhancement at portal-venous phase and delayed phase. TIC curve shape mainly showed sharply fast ascent and descent. CEUS can provide more effective image information in diagnosis of the liver metastases.2,CEUS can detect more lesions than conventional modalities.