3-Dimensional reconstruction of the venous system in patients suffering from pulsatile tinnitus

Abstract

Conclusions: An abrupt change in the venous caliber, producing turbulent flow, may be a cause of pulsatile tinnitus (PT). The largest area/smallest area (L/S) ratio >4.75 may be a criterion indicating abrupt caliber change and causing PT. Objectives: Contrast-enhanced CT is recommended as an initial work-up modality in PT. But, in the majority of cases, no definite pathology can be found, even after extensive work-up. In these cases, the unilateral dominant venous system may be the cause of PT. The aim of this study was to compare, through 3D-reformatted images of the intracranial venous system, the volume, cross-sectional area, and caliber changes in patients with PT and normal controls. Methods: This was a cross-sectional study set in a tertiary referral center. Eleven patients (11 unilateral PT ears) and 12 normal control ears were enrolled. All the subjects were confirmed with normal CT angiography findings. The intracranial venous structure was three-dimensionally reconstructed. Three areas with the largest and the smallest dimension were selected for further analysis: the transverse sinus (T), isthmus (I), and the jugular bulb (B). The total volume, cross-sectional area, and cross-sectional area ratios of the three areas were compared in the PT group and the normal control group. Results: The L/S ratio was significantly increased in the PT group (5.01), compared with the control group (3.42). When the threshold value of the L/S ratio was assessed by the ROC method, 4.75 seemed to be the significant dissecting point. The sensitivity of this method was 0.64 and the specificity was 0.83.