Background: Asymmetry between the transverse sinuses (TS) is quite common. We sought to test the possible hypothesis that certain anatomical features - namely, occipital lobe bending, Gibraltar sign of superior sagittal sinus groove (SSS) and jugular foramen (JF) dimensions - can predict dominance of the transverse sinuses on routine axial T1- and T2-weighted images.
Materials and methods: One hundred consecutively acquired combined MRI-MRV studies of brain were reviewed. On non-contrast axial T1WI, each reviewer assessed the occipital lobe bending, and Gibraltar sign of SSS groove; on axial T2-weighted images, JF dimensions were measured. TS cross-sectional area was measured on non-contrast sagittal 2-dimensional phase contrast MRV images and served as the reference standard.
Results: Of the 51 subjects with right-dominant TS, 37 had occipital bending to the right side and 35 showed sloping of the Gibraltar sign to right side. Of the 18 subjects with left dominant TS, 10 had occipital bending to left side and 13 showed left-sided sloping of the Gibraltar sign. Of the 31 subjects with co-dominant TS, 15 had no occipital bending and 20 showed no sloping of the Gibraltar sign. Mean right and left JF dimensions were higher in the right and left dominant TS respectively with no significant differences in patients with co-dominant sinus (p < 0.02).
Conclusion: Right occipital bending had a good association with right TS dominance. The other two parameters- Gibraltar sign of superior sagittal sinus groove and jugular foramen dimensions - did not have a very good association with respect to TS dominance.
Keywords: Hypoplasia; jugular foramen; occcipital bending; transverse sinus.