MRI investigation on outflow segment of cerebral venous system and its significance with increased intracraulai pressure

Abstract

Objective To measure and compare the imaging (MRI) features of outflow segment of cerebral venous system under increased and normal intracmnial pressure (ICP) and describe the stenosis formed before the venous sinus to explore the possible biological significances and clinical values of cerebral venous system in the regulating of angiostenosis. Methods Forty patients that presented both increased ICP symptoms and more or less hydrocephalus were selected as experimental group and 10 normal volunteers were selected as control group. Both the 2 groups were underwent 2D-TOF MRI with the following parameters: repetition time/echo time, 50/4.9 milliseconds; flip angle, 45°;field of view, 250 min×250 mm; matrix, 256×256 pixels; section thickness, 1.5 mm. The original images and data of the cerebral bridging veins and cerebral venous were recorded, and then, sinus Syngo fast view imaging system was used to process and analyze them. The diameter of cerebral bridging veins under different pressures was measured. Results The diameter of cerebral bridging veins in the experimental group was longer than that in the control group. A short and narrow length in MRI was obviously shown in most increased ICP patients resulting from signal weakness even disappearance at the outflow segment of cerebral venous system, while only 1 volunteer was showed the existence of signal weakness of similar imaging. Conclusion Cerebral bridging veins, the last passageway of the cerebral venous system, can passively influence the intraeranial pressure environment to regulate the level of ICP.The increased length of diameter of cerebral bridging veins under high pressure indicates that stenosis can induce hematomain the vein by limiting the drainage of venous blood. Key words: Increased intracranial pressure; Cerebral venous system; Brain bridging vein; MR venography