SMALL ARTERIAL-PORTAL VENOUS SHUNTS - A CAUSE OF PSEUDOLESIONS AT HEPATIC IMAGING

PURPOSE: To compare hepatic angiographic findings of small arterial-po rtal venous shunts with those of other imaging modalities, and to dete rmine whether these shunts are related to hepatocellular carcinoma. MA TERIALS AND METHODS: At hepatic angiography in 223 patients, small art erial-portal venous shunts not directly related to hepatocellular carc inoma and focal areas of parenchymal contrast material enhancement mor e than 1 cm in diameter were found in 28 patients. These 28 patients w ere prospectively evaluated with computed tomography (CT) during arter ial portography (CTAP) (n = 12), CT after iodized oil administration ( n = 23), intraoperative ultrasonography (n = 5), or follow-up hepatic angiography (n = 13). Magnetic resonance (MR) images (n = 10) and dyna mic CT scans (n = 4) in these patients were retrospectively reviewed. RESULTS: Arterial-portal venous shunts noted at angiography manifested as perfusion defects at CTAP in 10 patients and as an area of arteria l contrast enhancement at dynamic CT in three patients. No lesion was seen at MR imaging, and no persistent iodized oil uptake was seen at C T. There was no evidence of hepatocellular carcinoma tumor growth arou nd the shunts at follow-up angiography, and no tumor was present at su rgery. CONCLUSION: Understanding of the hemodynamic changes caused by these small shunts can aid in the interpretation of vascular imaging f indings.