Role of contrast-enhanced ultrasound for preoperative detection of colorectal liver metastases-compared with histopathologic results

Abstract

Objective To evaluate the role of contrast-enhanced ultrasound (CEUS) for preoperative detection of colorectal liver metastases.Methods 42 consecutive patients with colorectal liver metastases confirmed by histopathology after surgery were recruited in the study.They all had undergone preoperative CEUS examination with contrast agent SonoVue.The number,location and size of the hepatic lesions found by CEUS were correlated with postoperatively histopathologic results on a lesion-by-lesion basis.Results 96 liver metastases in 42 patients with colorectal cancer had been resected and confirmed by histophathology.The size of the metastatic lesions ranged from 0.3～8.5 cm [average (2.6 ± 1.8)cm].From one to eight metastatic lesions were detected in one patient.21 (21.9％) metastatic lesions were equal to or less than 1.0 cm.86 of 96 metastatic lesions were correctly depicted by CEUS,with a sensitivity of 89.6％.And the sensitivity for metastatic lesions equal to or less than 1.0 cm was 71.4％ (15 of 21 tumors) by CEUS.35 metastatic lesions were found between the portal venous phase and late phase by CEUS and 19 (54.3％) metastatic lesions among them could not be detected at conventional ultrasound.The curative resection was performed in 37 (88.1％) of 42 patients.With 3 - 39 months follow-up,the intrahepatic recurrence rate within two years was 32.4％ (12 of 37 patients) and the one-year survival rate was 90.0％.Conclusions CEUS is highly sensitive for detecting liver metastases resulted from colorectal cancer,especially for small metastatic lesions.CEUS is helpful to choose reasonable therapeutic strategies and can be regarded as one of the most importantly and noninvasively preoperative imaging modalities. Key words: Ultrasonography; Microbubbles; Colorectal neoplasms; Liver neoplasms; Neoplasm metastases