COMPARISON OF DYNAMIC CONTRAST-ENHANCED MRI AND DOPPLER ULTRASOUND INTHE PREOPERATIVE ASSESSMENT OF THE PORTAL VENOUS SYSTEM

The purpose of this study was to compare dynamic contrast enhanced MRI (DCEMR) with Doppler ultrasound (US) in the assessment of portal veno us anatomy and to analyse the causes of discrepancy. Over a 1 year per iod, 97 patients undergoing assessment prior to hepatic surgery underw ent imaging of the liver and portal venous system using US with colour and spectral Doppler and MRI with axial T-2 weighted spin echo (SE) a nd coronal oblique T, weighted rapid gradient echo (GRE) imaging befor e and immediately after bolus injection of Gd-DTPA (0.1 mmol kg(-1)). When the US and MRI findings were discrepant, the images were reviewed by two observers and compared with surgical findings. US and DCEMR we re concordant in 90 patients (portal vein patent in 80, occluded in 10 ). In three patients with cirrhosis and gross ascites the portal vein was reported as occluded on US and patent on MRI; surgery confirmed th e MRI findings. In one patient the portal vein was patent on US but no t on MRI, but there was a 3 week interval between the examinations. In three patients the portal vein was patent on US, but MRI detected occ lusion of intrahepatic portal vein branches in two, and encasement of an intrahepatic branch in the third case. Spontaneous splenorenal shun ts were seen in 15 patients only on MRI; varices were seen in 39 patie nts on MRI and in 22 patients on US. Both US and DCEMR contribute to t he pre-operative assessment of the portal venous system. MRI provides additional information over US in assessing intrahepatic portal branch es and detecting varices and splenorenal shunts, and is recommended fo r all surgical candidates and in patients with abnormal portal venous anatomy and equivocal US findings.