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

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.

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.

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.

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.