Transverse Sinus Stenosis Is the Most Sensitive MR Imaging Correlate of Idiopathic Intracranial Hypertension

Patients with idiopathic intracranial hypertension have transverse sinus stenosis on gadolinium-bolused MRV, but other MR imaging signs are less consistently seen. Our aim was to demonstrate that transverse sinus stenosis could be identified on conventional MR imaging, and this identification would allow improved diagnostic sensitivity to this condition.

MR imaging and MRV images from 63 patients with idiopathic intracranial hypertension and 96 controls were reviewed by using 3 independent procedures. MRV images were graded for the presence and degree of stenosis of the transverse sinus. Postgadolinium coronal T1-weighted sequences were evaluated independent of MRV. The dimensions of the proximal and distal transverse sinus were measured from the MRV examinations, and the cross-sectional area of the transverse sinus was calculated. Correlation among the 3 modes of evaluation of the transverse sinus was conducted by using Wilcoxon/Kruskal-Wallis, Pearson, and Spearman ρ nonparametric statistical techniques.

Transverse sinus stenosis was identified bilaterally on MRV in 94% of patients with idiopathic intracranial hypertension and in 3% of controls. On coronal T1 postgadolinium MR images, transverse sinus stenosis was identified in 83% of patients with idiopathic intracranial hypertension and 7% of controls. Previously described MR imaging signs of intracranial hypertension were identified in 8%-61% of patients with idiopathic intracranial hypertension. Correlation among the 3 modes of evaluation was highly significant (P < .0001).

Even without the assistance of an MRV sequence, neuroradiologists can validly identify bilateral transverse sinus stenosis in patients with intracranial hypertension more reliably than other previously described MR imaging findings in this condition. We conclude that transverse sinus stenosis is the most useful and sensitive imaging indicator of this disease state.