Case Notes
History
53 year old female who presented with acute onset diplopia and imaging evidence of dural sinus thrombosis affecting the torcular herophile, the left mesial transverse sinus, and the parietal segment of the SSS. Patient had evidence of meningitis and right sigmoid region epidural abscess. Patient was treated medically and with a right mastoidectomy. This patient is being reimaged at 10 days after the initial imaging.Exam
MR diffusion sequences with DWI & ADC maps
Purpose
Assess whether the diffusion maps (DWI & ADC) are positive for recent stroke within the venous egress zone.
Assess for hemorrhagic conversion (hematoma formation) using the Bo initial sequence on diffusion MR.
Assess for diffusion positivity in nasopharyngeal infection or infiltrative mass (both are typically positive on MR diffusion). These lesions can invade the cavernous sinus.
Assess for diffusion positivity in infection or infiltrative mass with the otomastoid and posterior skull base (often positive on MR diffusion). These lesions can invade the transverse sinus and inferior petrosal sinus.
Exclude concurrent arterial stroke.
Purpose
Assess whether the diffusion maps (DWI & ADC) are positive for recent stroke within the venous egress zone.
Assess for hemorrhagic conversion (hematoma formation) using the Bo initial sequence on diffusion MR.
Assess for diffusion positivity in nasopharyngeal infection or infiltrative mass (both are typically positive on MR diffusion). These lesions can invade the cavernous sinus.
Assess for diffusion positivity in infection or infiltrative mass with the otomastoid and posterior skull base (often positive on MR diffusion). These lesions can invade the transverse sinus and inferior petrosal sinus.
Exclude concurrent arterial stroke.
Prior Study
Initial admission imaging Initial imaging at the time of presentation demonstrated right coalescent mastoiditis, evidence of meningitis and dural sinus thrombosis affecting the torcula, left transverse sinus and the parietal segment of the SSS. There was a punctate area positive on both FLAIR and MR diffusion in the left superior vermic area (possible ischemic event). The right sigmoid sinus was partially compressed by a small epidural abscess, but was otherwise patent.CT head
Acute thrombus has progressed and is now evident in most of the superior sagittal sinus (SSS), the straight sinus, the torcular herophile, the right transverse sinus and the initial segment of the left transverse sinus. The hydrocephalus seen on initial imaging has resolved.
CT perfusion: No CT perfusion imaging is available
CTV of the neck: No neck CTV imaging was available
MRV of the head There are progressive dural CVT changes (compared to the initial MRV) with widespread dural sinus thromboses (SSS, torcula, and both transverse sinuses). The lateral aspect of the left transverse sinus wall is opacified but drains not through its' lumen to the sigmoid sinus, but rather into dural emissary channels. There is no apparent cortical vein thrombosis. The major veins are all patent; the vertex veins interconnect across the midline through the vertex venous lacunae. The pial/dural anastomoses combine with expanded dural wall venous plexes, and opened emissary venous channels to provide the dominant means of cerebral venous egress in this case, where there is thrombosis of both sigmoid sinuses.
Post contrast head CT No post contrast CT was available
Pre and post contrast T1-w MR
There are multiple dural sinus thromboses, as above, without cortical vein occlusions. There is reasonably functional collateral venous drainage is present utilizing expansion of the dural wall venous plexes, the left lateral tentorial venous confluence connected to the superior sylvian venous plexus egress route. The major venous egress routes for the deep central and subependymal veins appear to course through supra to infratentoral connections through the superior vermic vein and LAM collaterals ultimately draining into the petrosal veins. There is minimal evidence of persistently raised CSF pressure. There are expected post operative changes in the right mastoid area.