Contrast-enhanced ultrasound (CEUS) shows high sensitivity, accuracy, and specificity for differentiating benign and malignant portal vein thrombosis (PVT) in patients with hepatocellular carcinoma (HCC), according to a team of Italian researchers.
"We think that in this application, in most cases (CEUS) should be considered the first and often the sole diagnostic tool in cirrhotic patients with portal thrombosis, avoiding invasive, expensive, and less sensitive techniques," said Dr. Luciano Tarantino of San Giovanni di Dio Hospital in Torre del Greco, Italy. He presented his team's research at the 2006 RSNA meeting in Chicago.
To assess the sensitivity and specificity of CEUS in distinguishing between benign and malignant PVT in a large series of cirrhotic patients, the study team prospectively evaluated 205 consecutive cirrhotic patients presenting with PVT of the main portal vein (62 patients), right portal vein (94), and/or left portal vein (111 patients). The patients included 138 males and 67 females with a mean age of 64.
The patients included a previous diagnosis of HCC that was treated (122 patients), synchronous diagnosis of PVT and HCC (17 patients), diagnosis of cholangiocarcinoma (two cases), and no evidence of malignant liver lesions (64 cases).
The patients received CEUS at low-mechanical index on an SSD-500 extended scanner (Aloka, Tokyo) following an intravenous injection of 5 mL of SonoVue (Bracco, Milan, Italy). The presence of thrombus enhancement on the CEUS exam was considered diagnostic for malignant PVT.
For the purposes of the study, the gold standard was bimonthly follow-up with color Doppler ultrasound. Shrinkage of the thrombus and/or recanalization of the vessels on the color Doppler study during follow-up were considered diagnostic for benign PVT, while enlargement of the thrombus, disruption of the vessel's wall, and parenchymal infiltration over follow-up were considered consistent with malignancy, according to Tarantino.
CEUS enhancement of the thrombus was seen in 126 of the 205 (61%) of the cases. At mean follow-up at 22 months, 134 of the 205 (65%) showed signs of malignant PVT, Tarantino said. The test yielded 94% sensitivity, 100% specificity, 100% positive predictive value, 90% negative predictive value, and 96% accuracy.
The eight false-negative patients included two cases with PVT from cholangiocarcinoma, Tarantino said.
"The study confirms the high accuracy and specificity of CEUS in the diagnosis of HCC thrombosis in cirrhotic patients," Tarantino said.
By Erik L. Ridley
AuntMinnie.com staff writer
December 7, 2006
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