Differential diagnosis of hepatic tumors: Value of contrast-enhanced harmonic Sonography using the newly developed contrast agent, Sonazoid

Objective: To clarify the value of contrast-enhanced harmonic ultrasonography ( US) with Sonazoid, a second-generation US contrast agent, in the differential diagnosis of liver tumors compared to dynamic CT. Methods: A total of 249 hepatic nodules in 214 patients were studied; these included 177 hepatocellular carcinomas ( HCCs), 42 liver metastases, 20 liver hemangiomas, 6 dysplastic nodules and 4 focal nodular hyperplasias ( FNHs). After the injection of Sonazoid, nodules were scanned using real-time contrast-enhanced harmonic US in the vascular phases, i. e. the early and late vascular phases, and the Kupffer phase. Results: Six enhancement patterns were identified to be significant for the differential diagnosis of hepatic tumors. In HCCs, the presence of intratumoral vessels supplied from the periphery and fast washout ( sensitivity, 96.6%; specificity, 94.4%) were the most typical characteristics. In metastases, the presence of rim- like enhancement with peripheral tumor vessels ( sensitivity, 88.1%; specificity, 100%) was the typical pattern. In hemangiomas, the presence of intratumoral hypoperfusion images with globular or cotton wool-like pooling, which continue to the late vascular phase ( sensitivity, 90.0%; specificity, 99.6%), was typical. In dysplastic nodules, the presence of portal enhancement without arterial supply in the early vascular phase and the presence of intratumoral uptake in the Kupffer phase ( sensitivity, 83.3%; specificity, 100%) were the most typical patterns. In FNHs, the presence of a spoke-wheel pattern in the early vascular phase with dense staining in the late vascular phase, and positive uptake within the nodule in the Kupffer phase ( sensitivity, 100%; specificity, 100%) were the most typical patterns. Conclusion: Contrast-enhanced harmonic US with Sonazoid allowed intimate vascular and Kupffer imaging and, therefore, is useful for the differential diagnosis of hepatic tumors. Copyright (c) 2008 S. Karger AG, Basel.