Hemodynamic assessments of venous pulsatile tinnitus using 4D-flow MRI

Objective To use 4D-flow MRI to characterize hemodynamics of transverse and sigmoid sinus in venous pulsatile tinnitus (PT) patients and to investigate their differences vs healthy controls. Methods A total of 21 patients with venous PT and 11 healthy controls were included in the retrospective study. All participants underwent 4D-flow and magnetic resonance venography scan in a 3.0T magnetic resonance scanner. All visualization, quantification, and analysis of 4D-flow data were performed using dedicated software. Two independent reviewers evaluated the existence of vortex or turbulence. Covariance analysis adjusted for age was used to compare average through-plane velocity (V-tp_avg), maximum through-plane velocity (V-tp_max), average velocity (V-avg), maximum velocity (V-max), average blood flow (Flow(avg)), and pulsatility index (PI) between PT and control group. Results There were hemodynamic differences between PT patients and healthy controls. Compared with the control group, the PT group showed significantly higher V-tp_avg, V-tp_max, V-avg, V-max, and Flow(avg), and slightly higher PI. For the assessment of flow pattern, inter-reader reproducibility was excellent (kappa = 1.00). Vortex or turbulence was observed in PT patients with good sensitivity (86.4%) and specificity (90.9%). Drainage dominance was more frequently observed in patients (15/21, 71.4%) than healthy controls (4/11, 36.4%). Conclusions Significant hemodynamic differences were found between venous PT patients and healthy controls with 4D-flow MRI. Hemodynamic conditions could serve as noninvasive biomarkers for diagnosis and treatment evaluation of venous PT. Classification of evidence This study provides Class III evidence that 4D-flow MRI accurately identifies patients with venous PT.