Case Images
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
Purpose
Assess the noncontrast T1-w MR for hyperintense thrombus in one or more dural sinuses (i.e. the delta sign).
Assess the noncontrast T1-w MR for hyperintense thrombus in one or more pial or deep central veins.
Assess the noncontrast T1-w MR for blood products (SAH, hemorrhagic conversion).
Note: acute thrombus may be hyperintense on T1-w MR, just as it is hyperdense on CT, but it depends on the presence of met hemoglobin. Therefore,thrombi become hyperintense later than hyperdensity on CT. Hyperacute intraluminal thrombus on noncontrast T1 is more often isodense relative to brain but the isodense clot removes the expected flow void (actually a technical saturation effect).
Assess noncontrast T1 MR for venous congestion within the expanded medullary veins due to distal venous egress block.
Assess post contrast T1 sequences for intraluminal dural sinus thrombosis. T1-w post contrast exams, especially with multiplanar reconstruction, can discriminate enhancement in the dural sinus wall collateral from intraluminal (non enhancing) thrombus (i.e. the empty delta sign), when viewed in cross-section.
Assess post contrast T1 sequence for evidence of pial venous collaterals (typically appear serpiginous, hyperemic, drain the wrong way, the vein size changes from being larger next to the dural sinus to being larger at their inception site).
Assess the post-contrast T1 sequence for post ischemic contrast leak (i.e. venous post sichemic dysautoregulation).
Assess the post-contrast T1 sequence for unexpected exaggerated filling of atypical venous egress routes (i.e. filling into the orbits or posterior fossa veins or the nasopharyngeal venous plexus (evidence of re-routing of intracranial venous egress).
Assess for evidence of raised intracranial pressure, which includes evidence of brain swelling from venous congestion, optic hydrops/retroglobal edema, early hydrocephalus, effaced sulci, and possibly mass effects with herniation. These findings fall under the umbrella of CVT related pseudotumor.
Assess for nasopharyngeal/retropharyngeal infection/tumor with skull base extension and possible dural or cavernous sinus thrombosis.
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.
Dicom
Findings
| MR T1-W Sequence both with & without Contrast | Correct Answer | Your Answer |
|---|---|---|
|
There is luminal abnormal isointensity (lack of flow void) or hyperintensity within one or more dural sinuses (delta sign) indicative of acute thrombus on the noncontrast T1. |
Yes | NA |
|
There is evidence of hyperintense or hypointensity within one or more cortical or central veins on noncontrast T1. |
No | NA |
|
There is evidence of dilatation of the intraorbital veins, and optic hydrops (dilated CSF space around the optic nerves) on pre or post contrast T1 MR. |
No | NA |
|
There is evidence of abnormal ventriculomegaly consistent with early hydrocephalus. |
No | NA |
|
There is evidence of dural sinus filling defect (empty delta sign) indicating thrombosis within one or more dural sinuses on the post contrast T1. |
Yes | NA |
|
There is evidence of dural sinus filling defect indicating thrombosis within the cavernous sinus and either its' afferent input or efferent egress veins on the post contrast T1. |
No | NA |
|
There is evidence of mural enhancement or actual luminal filling defect within a cortical or central vein indicating acute thrombus on post contrast T1. |
No | NA |
|
There is evidence of mural enhancement or intraluminal filling defect indicating thrombosis in an ophthalmic vein on post contrast T1. |
No | NA |
|
There is evidence of parenchymal contrast enhancement in the region of the affected venous zone on post contrast T1 indicative of vascular leak. |
No | NA |
|
There is evidence of pial venous collateral veins (typically appear serpiginous, enlarged size, draining the reversed directiong, with the size changed from being larger next to the dural sinus to being larger at there inception site on the post constrast T1 MR). |
Yes | NA |
|
There is prominence of any of the pial/dural anastomotic sites (i.e. vertex venous lacunae, tenorial confluences, or cavernous sinus/retropharyngeal venous plexus) on the post contrast T1-w sequence. |
Yes | NA |
|
There is evidence of unexpected regional cortical vein enlargement (arterialization of othersise NL veins), consistent with the combination of a dural AV fistula plus dural sinus stenosis/thrombosis on post contrast T1. |
No | NA |
|
There is evidence of skull base destruction (infection/tumor) leading to cavernous or dural sinus thrombosis. |
Yes | NA |
|
There is evidence of hemorrhagic conversion |
No | NA |
| Other | Correct Answer | Your Answer |
|---|---|---|
|
Other findings are present consistent with a disorder other than CVT. |
No | NA |
Impression
Expert Answer
All of the above are true.
Your Answer
Recommendations & Acuity
Recommendations
Expert Answer
Proceed with additional CVT imaging
Your Answer
Acuity
Expert Answer
Emergent: non-routine communication required immediately or within 30 minutes
