Abstract
A new microbubble agent, Sonazoid®, provides parenchyma-specific contrast images in ultrasound (US) imaging examinations. With real-time imaging in the vascular and post-vascular phases provided by use of this agent, an accurate diagnosis of liver tumors is possible. A Japanese man in his 50s visited our hospital with complaints of abdominal distension and upper abdominal pain. Abdominal contrast-enhanced computed tomography revealed a 5-cm non-enhanced mass lesion in the caudate region of the pancreas, though no apparent tumor was shown in the liver. A conventional US examination revealed a well-demarcated low-echoic nodule in the S4 region and multiple focal spared areas with a bright hepatic parenchyma, indicating a fatty liver. In addition, contrast-enhanced US with Sonazoid® demonstrated that the hypoechoic area in the S4 region was slightly stained in the arterial phase and washed out in the portal phase, while only the hypoechoic area in the S4 region showed an accumulation defect in the post-vascular phase, indicating that the lesion should be diagnosed as a metastatic liver tumor. Contrast-enhanced US with Sonazoid® is useful for differentiating tumors from focal spared areas in fatty livers.
