Improved detection of liver metastases with contrast-enhanced wideband harmonic imaging: comparison with CT findings.

OBJECTIVE: To evaluate the capability of contrast-enhanced wideband harmonic imaging (WHI) to detect liver metastases in comparison with fundamental B-mode US and postcontrast CT.
METHODS: We studied 27 patients with hepatic metastases from different malignancies with conventional B-mode sonography, WHI 3 min after injection of contrast agent (Levovist(R) 2.5 g, 300 mg/ml) and postcontrast helical CT (HCT). The number and location of the lesions and the smallest lesion for each patient were noted by two different observers and compared.
RESULTS: Both readers recorded an increase in the number of lesions in harmonic mode compared with conventional B-mode in all 27 patients with hepatic metastases with a mean increase in both observers from 9.3 lesions with B-mode to 18.8 lesions with WHI. The smallest lesions were detected with WHI when compared with conventional US and HCT (2 mm with WHI, 5 mm with B-mode and 5 mm with CT). WHI detected more lesions than conventional US or HCT.
CONCLUSIONS: Contrast-enhanced WHI seems superior to conventional US and HCT for the detection of hepatic metastases, specially for those nodules under 1 cm of diameter.