Presentation
Bilateral lower limb weakness. A contrast-enhanced MRI of the brain and whole spine was requested.
Patient Data
Asymmetrical enlargement of the left sigmoid venous sinus and jugular bulb with associated signal alteration more prominent at T1 and FLAIR eliciting hyperintensity. No blooming in T2 GRE and homogenous enhancement in the post-contrast study.
Case Discussion
Sluggish cerebral venous flow may mimic subacute dural venous sinus thrombosis due to loss of the normal flow void in T1 and T2. T2 GRE is helpful in this case as the sluggish flow shows no blooming while subacute thrombosis blooms owing to the paramagnetic effect of methemoglobin. If it is still equivocal and the clinical history is relevant, further MRV or contrast-enhanced MRI is mandatory to exclude thrombosis.
In this case, the T2 GRE was conclusive to exclude thrombosis, and the intravenous contrast injection was done for assessment of a spinal mass.