755 0361 -803X/89/1 534-0755 C American Roentgen Ray Society MR Angiography and Dynamic Flow Evaluation of the Portal Venous System Robert R. Edelman1 Bin Zhao1’2 Cheng Liu1’2 Klaus U. Wentz1’3 Heinrich P. Mattle4 J. Paul Finn4 Cohn McArdIe1 Received March 31 , 1989; accepted after revi- sion May 15, 1989. 1 Department of Radiology, Beth Israel Hospital, 330 Brookline Ave., Boston, MA 02215. Address reprint requests to A. A. Edelman. 2 Shandong Provincial Medical Imaging Re- search Institute and Dept. of Radiology, Shandong Provincial Hospital, 396 Jing Wu Ad., Jinan, Peo- pie’s Republic of China. 3Department of Radiology, Klinikum Mannheim, Theodor-Kutzer-Ufer, 6800 Mannheim 1, W. Ger- many. 4Department of Radiology, New England Dea- coness Hospital, 185 Pilgrim Rd., Boston, MA 02215. We studied the value of MR angiographic techniques in imaging the portal venous system. Projection angiograms were created by postprocessing a series of two-dimen- sional, flow-compensated gradient-echo images. Flow velocity was determined by a bolus-tracking method with radiofrequency tagging and multiple data readout periods. Each image was acquired during a breath-hold. MR angiography was applied to six normal subjects and four patients with abnormal hemodynamics in the portal venous system. Flow velocity determined by MR was correlated with the resufts of duplex sonography. The main portal vein and intrahepatic branches were shown in all cases. Portosystemic collaterals were identified in all patients with portal hypertension. In normal subjects, peak flow velocities (17.9 ± 2.8 cm/sec) on MR correlated well with values determined by duplex sonography (17.5 ± 2.2 cm/sec) (r = .846, p < .04). Reversed portal blood flow was shown in two patients. One patient with portal vein thrombosis had no evidence of flow by MR angiography. Our results indicate that MR angiography can provide a three-dimensional display of normal and abnormal vascular anatomy as well as functional information in the portal venous system. AJR 153:755-760, October 1989 Numerous investigators have used MR to study blood flow [1 -4]. Time-of-flight and phase effects can be used to determine the direction and velocity of flow. Recently, methods for obtaining MR angiograms have been described [5-9]. These methods substantially overcome the limitations of two-dimensional tomographic acquisitions by displaying, in a single image, blood vessels within a thick volume, analogous to conventional angiograms. In this article, we describe MR angiography of the portal venous system in normal subjects and in patients with portal hyper- tension. Subjects and Methods Normal Volunteers and Patients In six healthy male volunteers, portal vein blood-flow velocities were determined by MR angiography and were correlated with the results of duplex sonography. Subjects fasted for at least 4 hr before both studies. The maximum time between completion of MR angiography and duplex sonography measurements did not exceed 30 mm. Four consecutive patients with portal hypertension and abnormal portal venous blood-flow dynamics shown by conventional angiography or duplex sonography were studied. One patient with a history of alcohol abuse had advanced liver cirrhosis. The diagnosis of portal hypertension was based on the finding of abdominal venous collaterals on a sonogram obtained 3 months before admission. A duplex sonogram made at admission suggested portal vein thrombosis, but a second study after the MR examination showed a patent portal vein with reversed flow. The second patient had an enlarged liver, esophageal varices proved by endoscopy, and a patent umbilical vein proved by sonography. In the third patient, the