[Transverse sinus blood flow characteristics of pulsatile tinnitus with dehiscent sigmoid plate based on 4D flow MRI]

Objective: To investigate the hemodynamic characteristics of transverse sinus with sigmoid sinus wall dehiscence (SSWD) of pulsatile tinnitus (PT) based on 4D flow MRI. Methods: Retrospective analysis was performed on all patients admitted to Beijing Friendship Hospital, Capital Medical University from January 2019 to January 2021 for dehiscent sigmoid plate pulsatile tinnitus. A total of 26 patients (sides) who met the criteria and underwent 4D flow MRI were included. A total of 26 subjects (46 sides), matched 1∶1 according to gender and age, were included in the normal healthy control group. Nonparametric rank sum test, Student's t test, and ANOVA were performed by SPSS 19.0 software. Binary Logistic regression was applied to the data with statistical significance. Results: There were more patients with dominant drainage on the affected side in PT group than in control group (73.1% vs. 42.3%). The incidence of transverse with a focal intraluminal filling defect and tapered stenosis was higher than that in control group (21.7% vs. 69.2%; 17.4% vs. 42.3%). Average through-plane velocity and maximum through-plane velocity in PT group were higher than those in control group [(33.75±13.88) cm/s vs. (15.84±7.21) cm/s; (93.19±33.55) cm/s vs. (40.40±14.40) cm/s]. The middle part and proximal end of Flow_avg (ml/s) in PT group were larger than those in control group [4.69 (2.87; 5.62) ml/s vs. 2.76 (1.67; 4.99) ml/s; 3.41 (2.16; 5.47) ml/s vs. 2.67 (1.68; 4.41) ml/s]. In control group, the velocity of transverse sinus changed relatively gently, while in PT group, the velocity of proximal sinus increased significantly. Binary Logistic regression showed that SSWD PT was independently correlated with proximal maximum flow velocity [OR=1.086(1.029-1.146),P=0.003]. Conclusion: 4D flow MRI showed that the dominant drainage and higher velocity at the proximal end of the transverse sinus might be an important hemodynamic characteristics of dehiscent sigmoid plate pulsatile tinnitus.