Assessment of cerebral venous sinus: Anatomical and functional diagnostic performance of three-dimensional reconstruction models based on venous sinus MRI and CT images

Venous sinus stenosis is commonly observed in patients presenting with pulsatile tinnitus (PT). While magnetic resonance imaging (MRI) and computed tomography (CT) are commonly used for assessing venous sinus geometries, the preferred modality remains unclear. In this study, we reconstructed the three-dimensional (3D) geometries of the venous sinus using MRI and CT imaging data from 20 PT patients. We conducted comparisons of the anatomical features of the venous sinus through case-wise analysis and anatomic geometrical parameter-wise analysis. Our findings indicate that by taking the geometries from CT as a reference, MRI could provide a better illustration of venous structure, primarily due to a stronger flow signal concentrated in the vascular tree. We observed high agreements in anatomic parameters measured from 3D geometries reconstructed based on CT and MRI in 19 out of 20 cases. Notably, the cross-sectional area of the sinus and segment length displayed the highest consistency, with a mean difference of -5.01% and 6.5% between modalities, respectively. In addition, we noticed that 55% of cases exhibited consistency in analyzing the confluence of the sinus, while variants of connectivity and collateral branching were observed between CT and MRI. Importantly, CT-based geometric reconstruction provided better detail of inflow side branches in the straight sinus, whereas MRI preserved more side branches of outflow in the downstream sinus. It is important to note that CT-based evaluation may be affected by the bone structures surrounding the venous sinus, whereas MRI-based evaluation focuses on blood flow to the segments, potentially indicating both anatomical and functional abnormalities.