Published online Dec 28, 2014. doi: 10.3748/wjg.v20.i48.18375
Revised: June 18, 2014
Accepted: September 12, 2014
Published online: December 28, 2014
Processing time: 253 Days and 16.7 Hours
AIM: To investigate contrast-enhanced ultrasound (CEUS) findings in portal venous system aneurysms (PVSAs).
METHODS: In this multi-center, retrospective, case series study, we evaluated CEUS features of seven cases of PVSAs that were found incidentally on conventional ultrasound in the period 2007-2013. Three Ultrasound Centers were involved (Chieti, Italy, Bad Mergentheim, Germany, and Cluj-Napoca, Romania). All patients underwent CEUS with Sonovue® (Bracco, Milan, Italy) at a standard dose of 2.4 mL, followed by 10 mL of 0.9% saline solution. The examinations were performed using multifrequency transducers and low mechanical index. We considered aneurysmal a focal dilatation of the portal venous system with a size that was significantly greater than the remaining segments of the same vein, and that was equal or larger than 21 mm for the extrahepatic segments of portal venous system, main portal vein and bifurcation, and 9 mm for the intrahepatic branches.
RESULTS: After contrast agent injection, all PVSAs were not enhanced in the arterial phase (starting 8-22 s). All PVSAs were then rapidly enhanced in the early portal venous phase (starting three to five seconds after the arterial phase, 11-30 s), with persistence and slow washout of the contrast agent in the late phase (starting 120 s). In all patients, CEUS confirmed the presence of a “to-and-fro” flow by showing a swirling pattern within the dilatation in the early portal venous phase. CEUS also improved the delineation of the lumen, and was reliable in showing its patency degree and integrity of walls. In one patient, CEUS showed a partial enhancement of the lumen with a uniformly nonenhancing area in the portal venous and late phases, suggesting thrombosis.
CONCLUSION: In our case series, we found that CEUS could be useful in the assessment and follow-up of a PVSA. Further studies are needed to validate its diagnostic accuracy.
Core tip: Portal venous system aneurysms (PVSAs) are considered a rare disease. Ultrasound is the method of choice in the initial assessment of a suspected PVSA, by showing a focal enlargement of the portal venous system with typical color Doppler features. However, no studies have so far reported contrast-enhanced ultrasound (CEUS) findings. In this multi-center, retrospective, case series study we demonstrated, for the first time, that CEUS could be useful in the assessment and follow-up of a PVSA.