Hepatocellular carcinoma not detected with plain US: treatment with percutaneous ethanol injection under guidance with enhanced US.

To evaluate the usefulness of contrast material-enhanced ultrasound (US) in detection and treatment of hepatocellular carcinoma (HCC), carbon dioxide was injected as a contrast agent into the hepatic artery in 22 patients with HCC. Plain US had enabled detection of 24 HCC nodules in these patients. Contrast material-enhanced US enabled detection of seven additional nodules, which were confirmed as HCC by means of fine-needle aspiration biopsy performed under guidance with contrast-enhanced US. Six of these seven nodules were detected incidentally during examination of other suspected HCC nodules. Five of the seven nodules were treated with percutaneous ethanol injection (PEI) performed under guidance with contrast-enhanced US; the two other nodules were resected. Contrast-enhanced US made the HCC lesions visible for 15-60 minutes, sufficient time to mark the nodule with an iodized oil-ethanol solution for PEI. Because contrast-enhanced US enabled detection of additional nodules and performance of PEI in lesions not detected with plain US, it may help improve the treatment of HCC.