Diagnosis of Small Liver Metastasis:Comparison of Contrast-enhanced Ultrasound with Conventional Ultrasound

Objective To compare the accuracy and reliability between contrast-enhanced ultrasound (CEUS) and conventional ultrasound in diagnosis of 3cm liver metastases,and to discuss the role of CEUS in diagnosis of small liver metastases.Methods Eighty-seven patients with known malignancies and suspicious liver metastases were performed CEUS.The perfusion patterns of liver metastasis were evaluated and the graduation of score for the differential diagnosis between malignant and benign tumor were conducted before and after CEUS.Results The scores in 21 metastases (24.1%) evaluated by CEUS were higher 2～4 than that by conventional ultrasound,and 21 metastases (24.1%) higher 1.In 33 patients (37.90%),more metastases were observed by CEUS than by conventional ultrasound.There was significant difference in accuracy between CEUS and conventional ultrasound in diagnosis of small liver metastases (P0.01).Conclusion CEUS had unique advantage in qualitative diagnosis of small liver metastases.It improved sensitivity in detection of small hepatic metastases,which is useful for staging and selecting treatment protocols in patients with extra-hepatic original malignancies.