Analysis of the Vertebral Venous System in Relation to Cerebral Venous Drainage on MR Angiography

Baik, Seung Kug; Sohn, Chul Ho; Kim, Yong Sun; Kim, Gab Chul

Abstract

PURPOSE
In the supine position, cerebral venous drainage occurs primarily through the internal jugular veins, as seen on venous phase cerebral angiography. However, in the erect position, the vertebral venous system represents the major alternative pathway of cerebral venous drainage, while outflow through the internal jugular veins is absent or negligible. The purpose of this study is to evaluate the vertebral venous system and its relationship between the surrounding venous structures using magnetic resonance angiography (MRA) in the case of subjects in the supine position.
MATERIALS AND METHODS
We retrospectively reviewed the results of 65 patients (M:F=31:34, mean age: 61.6 years) who underwent multi-phase contrast-enhanced carotid MRA. The imaging studies were performed using a 3.0 T MR unit (TR: 5.2, TE: 1.1, FA: 20, 3.8 thickness, EC: 1). We analyzed the appearance and extent of the vertebral venous system (vertebral venous plexus and vertebral artery venous plexus) and the internal jugular vein on the venous phase images. We also evaluated the main drainage pattern of the cerebral venous drainage and the drainage pattern of the vertebral venous system. The visualized vertebral venous system was defined as either poor, vertebral venous plexus dominant, vertebral artery venous plexus dominant or mixed.
RESULTS
In the vertebral venous system, the vertebral artery venous plexus was visualized in 54 cases (83%). The appearance of the visualized vertebral artery venous plexus was symmetrical in 39 cases (72%) and asymmetrical in 15 cases (28%). The extent of the visualized vertebral artery venous plexus was partial in 26 cases (48%) and complete in 28 cases (52 %). The vertebral venous plexus was visualized in 62 cases (95%). The appearance of the visualized vertebral artery venous plexus was symmetrical in 43 cases (69%) and asymmetrical in 19 cases (31%). The extent of the visualized vertebral artery venous plexus was partial in 35 cases (56%) and complete in 27 cases (44%). The appearance of the visualized internal jugular vein was asymmetrical in 44 cases (68%) and symmetrical in 21 cases (32%). Of these 44 asymmetrical cases, 4 demonstrated partial non-visualization of the internal jugular vein. In these 4 cases, the ipsilateral vertebral venous system was well visualized. The main cerebral venous drainage occurred through the internal jugular vein in 62 cases (97%) and the vertebral venous system in 2 cases (3%). The drainage pattern of the vertebral venous system was poor in 14 cases (21%), vertebral venous plexus dominant in 11 cases (17%), vertebral artery venous plexus dominant in 18 cases (28%) and mixed in 22 cases (34%).
CONCLUSION
In the supine position, the vertebral venous system was well visualized. The vertebral venous system represented an alternative collateral pathway of the internal jugular vein in cerebral venous drainage. It may be that the vertebral venous system in used, or conversely the internal jugular vein, depending on the position of the subject.