ASSESSMENT OF THE PORTAL VENOUS SYSTEM USING ADVANCED CT TECHNIQUES

Abstract

A wide range of congenital and acquired condi¬tions may affect the portal venous system. Portal venous shunts, portal vein stenosis and pyle¬thrombosis may alter flow dynamics and lead to the development of venous collaterals, encepha¬lopathy and right-sided cardiac failure. Portal venous gas, pylephlebitis, and trauma to the portal venous system may be life threatening and require urgent attention. Portal venous calcification, cav¬ernous transformation of the portal vein and varix of the portal venous system can complicate portal vein surgery. Advanced CT scanners allow a high resolution, full evaluation of the portal vasculature with short acquisi¬tion time for a large volume allowing generation of high resolution angiograms with 3D reconstruction of vascular anatomy as well as simultaneous identi¬fication of any associated complications. The dis¬advantages of CT include ionizing radiation and nephrotoxicity of iodinated contrast ma¬terial The imaging modality of choice for the evalu¬ation of the portal venous system depends on the clinical scenario, various patient-specific factors, and local availability of the necessary equipment and experienced operators. Contrast enhanced CT angiography is considered the imaging modality of choice for the evaluation of the portal venous system. CT permits a comprehensive evaluation that allows the detection of congenital and acquired shunts, stenosis, thrombosis, phlebitis, gas, calcification, varix and trauma to the portal venous system. The choice of imaging modality for serial evaluations (monitoring) of portal venous system abnormalities is determined by the ability of that modality to detect the abnormality in the first instance.