Case Notes
History
51 year old female presenting with an acute left facial droop, left side weakness, and mental status change.Exam
Head MR Susceptibility (SWI) Sequence
Purpose
1. To identify sites of arterial thrombosis based on SWI blooming artifact in the proximal afferent arteries.
2. To assess the presence of venous stasis based on SWI blooming artifact within the deep medullary veins
3. To assess for venous collapse based on SWI blooming artifact in both the deep medullary veins and the draining central & cortical veins.
3. To identify sites of hematoma (blood extravasated into the neuropil) representing actual hemorrhagic conversion.
4. To identify sites of sequestered infarction (stagnant blood within the capillary bed), which implies virtually no transcapillary blood flow. This can be in the cortex (i.e. laminar necrosis, or in the parenchyma).
5. Compare the FLAIR & DWI sequences with the SWI sequence in order to differentiate between hemorrhagic conversion (hematoma formation within the neuropil) versus acutely sequestered completed infarction (non extravasated blood stagnated within the capillary bed).
6. To identify areas of hyperemia with dilated deep medullary veins, which are part of the physiologic hyperemia in the collateral stroke zone, since this is an expected finding and not evidence of venous stasis.
Purpose
1. To identify sites of arterial thrombosis based on SWI blooming artifact in the proximal afferent arteries.
2. To assess the presence of venous stasis based on SWI blooming artifact within the deep medullary veins
3. To assess for venous collapse based on SWI blooming artifact in both the deep medullary veins and the draining central & cortical veins.
3. To identify sites of hematoma (blood extravasated into the neuropil) representing actual hemorrhagic conversion.
4. To identify sites of sequestered infarction (stagnant blood within the capillary bed), which implies virtually no transcapillary blood flow. This can be in the cortex (i.e. laminar necrosis, or in the parenchyma).
5. Compare the FLAIR & DWI sequences with the SWI sequence in order to differentiate between hemorrhagic conversion (hematoma formation within the neuropil) versus acutely sequestered completed infarction (non extravasated blood stagnated within the capillary bed).
6. To identify areas of hyperemia with dilated deep medullary veins, which are part of the physiologic hyperemia in the collateral stroke zone, since this is an expected finding and not evidence of venous stasis.
Prior Study
CT headAbnormal right high cervical ICA consistent with dissection
CTA Final Impression
1. Rt. high cervical ICA dissection w/ limited antegrade blood flow beyond the 70% luminal stenosis The combination of antegrade flow plus pial collaterals revealed on cortical pial collateral gap.
2. Subtle reduction in the CT density within the venocapillary pool in the Rt. suprasylvian subcortical parietal white matter, likely representing end-of the-line ischemia in a posteriorly shifted watershed zone to the parietal white matter and the MCA-PCA watershed region. MR would be of value in determining whether there is actual acute post ischemic tissue in the region of the brain.
3. There is minimal post-ischemic dysautoregulation in the right superior division MCA.
4. Features of FMD in the left high ICA making FMD the likely the basis for the spontaneous right ICA dissection.
Findings for MR Diffusion: DWI/ADC Maps
Positive sites of diffusion were evident in the right mesial globus pallidus and in the right centrum semiovale mainly in the frontoparietal and parietal areas sparing the frontal and orbitofrontal white matter. These sites correspond to the mesial lenticulostriate and posterior part of the ACA-MCA watershed zones.
Findings for FLAIR MR Sequence
1. Known acute Rt. high cervical ICA dissection with limited antegrade blood flow beyond the 70% stenosis.
2. Positive diffusion for stroke in Rt. parietal MCA-PCA component of a posteriorly shifted watershed zone. There are likely two components of the stroke based on the difference in FLAIR conspicuity; the rostral part is likely acute and the caudal part is likely hyperacute. FLAIR is also positive in the mesial globus pallidus with the stroke age and or depth and duration similar to the more caudal part of the stroke in the centrum semiovale.
3. Positive early FLAIR signal in a hyperacute mesial lenticulostriate perforator branch.
4. No hemorrhagic transformation nor venous egress obstruction is evident.