Contrast-enhanced ultrasound vs multidetector-computed tomography for detecting liver metastases in colorectal cancer: a prospective, blinded, patient-by-patient analysis.

AIM: This study compared the sensitivity and specificity of contrast-enhanced ultrasound (CEUS) and multidetector-computed tomography (MDCT) in the detection of liver metastases in patients with colorectal cancer. METHOD: Between September 2004 and December 2008, 271 consecutive patients (146 men and 125 women; median age 68 years, range: 34-91 years) with primary colorectal cancer were evaluated. All underwent combined liver ultrasound and CEUS following intravenous injection of 2.4 ml of SonoVue(TM). The interval from injection to arrival time in the hepatic vein (ATHV) was noted. Contrast-enhanced MDCT in the portal phase was performed and interpreted blindly. In all patients, intra-operative ultrasound was used as the reference point. In addition, magnetic resonance imaging (MRI) or biopsy was performed on all suspicious lesions or if there was inconsistency in the results. RESULTS: Liver metastases were detected in 21 (8%) patients. Both CEUS and MDCT had a sensitivity of 85.7%, with respective specificities of 97.6% and 95.6%, and positive predictive values of 75%vs 62%. The negative predictive value of both methods was 99%. In patients with and without liver metastases, ATHV was 18 and 22 s, respectively (P < 0.05). CONCLUSION: CEUS has potential as a diagnostic alternative to MDCT in the detection of liver metastases. ATHV was shorter in patients with liver metastases.