Effects of different morphologic abnormalities on hemodynamics in patients with venous pulsatile tinnitus: A four‐dimensional flow magnetic resonance imaging study

The effects of morphologic abnormalities, including sigmoid sinus wall dehiscence (SSWD), transverse sinus stenosis (TSS), and sigmoid sinus diverticulum (SSD), on hemodynamics in venous pulsatile tinnitus (PT) patients have not been established. The aim of this study was to evaluate the effects of SSWD, TSS, and SSD on the hemodynamics of transverse‐sigmoid sinus in venous PT patients. This was a prospective study with 44 venous PT patients and 12 healthy controls. A 3 T/four‐dimensional (4D) flow magnetic resonance imaging with fast field echo was used. Computed tomography arteriography/venography was used to assess ipsilateral SSWD, TSS, and SSD. Maximum velocity (V (max)), average velocity (V (avg)), and average flow (Flow(avg)) were measured. Blood flow patterns were independently assessed by three neuroradiologists. One‐way analysis of variance or Kruskal–Wallis test was also used. On the symptomatic side, all patients had SSWD, 33 patients had TSS, and 22 patients had SSD. Compared with healthy controls, patients with TSS, without TSS, with SSD, and without SSD all showed higher V (max) (all p < 0.050), V (avg) (all p < 0.050), and Flow(avg) (all p < 0.050). Patients with TSS showed higher V (max) (p < 0.050) and V (avg) (p < 0.050) than those without TSS, and no significant difference in Flow(avg) was found between the two groups (p = 0.408). No significant differences in V (max), V (avg), and Flow(avg) were found between patients with and without SSD (all p = 1.000). Jet‐like flow in the stenosis and downstream of the stenosis was observed in all patients with TSS. Vortex in SSD was observed in 15 patients with SSD (68%). High blood velocity and flow may be characteristic markers of venous PT. SSWD may be a necessary condition for venous PT. TSS may further increase the blood velocity and form a jet‐like flow. SSD may be related to vortex formation but had no significant effect on blood velocity and flow. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 3