[Evaluation of hepatic tumors by contrast ultrasonography with carbon dioxide]

For evaluating hepatic tumors, ultrasonograms using carbon dioxide by arterial injection (CO2US) was performed in 37 patients, including 28 hepatocellular carcinomas, 11 hepatic metastases, and 3 hepatic hemangiomas. Hepatic tumors were enhanced by CO2US and easily identified. CO2US of hepatic tumors were classified into six patients. Generally, on CO2US hepatocellular carcinomas were well enhanced, and hepatic metastases had ring-like enhancement. Hepatic hemangiomas showed peripheral patchy enhancement. In the patients with hepatocellular carcinoma, the primary tumors were better identified on CO2US than conventional sonography. The daughter nodules with hepatocellular carcinoma were also better demonstrated than other examinations. CO2US is helpful in evaluating and differentiating hepatic tumors.