Portal hypertension: a review of portosystemic collateral pathways and endovascular interventions.

The portal vein is formed at the confluence of the splenic and superior mesenteric vein behind the head of the pancreas. Normal blood pressure within the portal system varies between 5 and 10 mmHg. Portal hypertension is defined when the gradient between the portal and systemic venous blood pressure exceeds 5 mmHg. The most common cause of portal hypertension is cirrhosis. In cirrhosis, portal hypertension develops due to extensive fibrosis within the liver parenchyma causing increased vascular resistance. In addition, the inability of the liver to metabolise certain vasodilators leads to hyperdynamic splanchnic circulation resulting in increased portal blood flow. Decompression of the portal pressure is achieved by formation of portosystemic collaterals. In this review, we will discuss the pathophysiology, anatomy, and imaging findings of spontaneous portosystemic collaterals and clinical manifestations of portal hypertension with emphasis on the role of interventional radiology in the management of complications related to portal hypertension.

64-Slice multidetector row CT angiography of the abdomen: comparison of low versus high concentration iodinated contrast media in a porcine model.

OBJECTIVE: In this study we aimed to assess the image quality and degree of vascular enhancement using low-concentration contrast media (LCCM) (300 mg I ml(-1)) and high-concentration contrast media (HCCM) (370 mg I ml(-1)) on 64-slice multidetector row CT (MDCT) abdominal CT angiography (CTA). In addition, we aimed to study the feasibility of using HCCM with a reduced total iodine dose. METHODS: CTA of the abdomen on a 64-slice MDCT was performed on 15 anaesthetised pigs. Study pigs were divided into three groups of five each based on the iodine concentration and dose received: Group A (LCCM; 300 mg I ml(-1)), Group B (HCCM; 370 mg I ml(-1)) and Group C HCCM with 20% less iodine dose. The total iodine injected was kept constant (600 mg kg(-1)) in Groups A and B. Qualitative and quantitative analyses were performed to study and compare each group for image quality, visibility of the branch order of the superior mesenteric artery (SMA), artefacts, degree of enhancement in the aorta and main stem arteries and uniformity of enhancement in the aorta. Groups were compared using the analysis of variance test. RESULTS: The image quality of 64-slice MDCT angiography was excellent with a mean score of 4.63 and confident visualisation of the third to fifth order branches of the SMA in all groups. Group B demonstrated superior vascular enhancement, as compared with Groups A and C (p≤0.05). Uniform aortic enhancement was achieved with the use of LCCM and HCCM with 20% less iodine dose. CONCLUSION: 64-slice MDCT angiography of the abdomen was of excellent quality. HCCM improves contrast enhancement and overall CTA image quality and allows the iodine dose to be reduced.

Inferior pancreaticoduodenal artery aneurysms in association with celiac axis stenosis or occlusion.

PURPOSE: To describe the pathophysiology, identification and management of inferior pancreaticoduodenal artery aneurysms in association with celiac axis stenosis or occlusion has been reported. REVIEW FINDINGS: These aneurysms are thought to arise due to increased flow through the pancreaticoduodenal arcades. The arcades first enlarge, and then form focal aneurysms which may rupture. The aneurysms can be treated through endovascular techniques or by surgery, though the former is a preferred approach.

Small ureterocele-like Gartner's duct cyst associated with ipsilateral renal aplasia: a case report.

Gartner's duct cyst associated with ipsilateral renal aplasia is a rare anomaly and fewer than 40 cases have been reported in the literature. A case of Gartner's duct cyst presenting like an ureterocele on sonography, intravenous pyelography and CT are described.