Case Notes
History
79 year old female presenting with sudden onset symptoms including Rt. facial droop, Rt. side weakness; the patient was nonverbal and not following commands; there is known history of secondary diabetes with hyperlipidemia.Exam
Head MR sequences (Diffusion w/ DWI & ADC maps) in this case the MR was obtained 6.5 hours after embolectomy and with new symptoms.
Purpose
1. To use the diffusion maps (DWI & ADC) to identify sites of hyperacute stroke matching an arterial zone.
2. To determine whether the positive diffusion zone matches a primary stem arterial region, a secondary stem arterial region, a trunk/division arterial region, a major branch region; or a distal arterial cortical zone, or any combination;
3. In cases where there are more than one ischemic sites to determine whether changes could be from an extra cranial embolic site, or whether they represent proximal clot lysis and subsequent distal embolization;
4. To determine whether the areas involved fit best with an embolic event or embolic shower (could be from proximal plaque or cardiac source, etc;
5. To determine whether the affected areas as recognizable as a watershed zone; usually in the context of currently patent major afferent arteries (ICA’ & vertebral arteries); there are often chronic extradural carotid or vertebral occlusions;
6. To determine whether the affected area(s) could represent stroke with an end of the line watershed pattern, based on the combination of occluded major afferent brain arteries plus incomplete circle of Willis plus any additional flow-limiting stenoses;
7. Evaluate the diffusion Bo sequence for hemorrhagic conversion.
Purpose
1. To use the diffusion maps (DWI & ADC) to identify sites of hyperacute stroke matching an arterial zone.
2. To determine whether the positive diffusion zone matches a primary stem arterial region, a secondary stem arterial region, a trunk/division arterial region, a major branch region; or a distal arterial cortical zone, or any combination;
3. In cases where there are more than one ischemic sites to determine whether changes could be from an extra cranial embolic site, or whether they represent proximal clot lysis and subsequent distal embolization;
4. To determine whether the areas involved fit best with an embolic event or embolic shower (could be from proximal plaque or cardiac source, etc;
5. To determine whether the affected areas as recognizable as a watershed zone; usually in the context of currently patent major afferent arteries (ICA’ & vertebral arteries); there are often chronic extradural carotid or vertebral occlusions;
6. To determine whether the affected area(s) could represent stroke with an end of the line watershed pattern, based on the combination of occluded major afferent brain arteries plus incomplete circle of Willis plus any additional flow-limiting stenoses;
7. Evaluate the diffusion Bo sequence for hemorrhagic conversion.
Prior Study
Final Impression for entire CTA1. Proximal left M1/M2 thrombus with reasonable pial collateral (pial collateral reaches the proximal thrombus on the delayed head CT.
2. There remains evidence of persistent significant oligemia mainly in the lateral lenticulostriate perfusion zone (likely completed stroke). Persistent, but not as dense as the lateral basal ganglia but consistent with ischemic penumbra) is the oligemia remaining in the anterior insular and lateral orbitofrontal cortex. Lesser oligemia (tissue at risk) is evident the remaining superior division to the posterior insular and lateral cortical territories.
3. The persistently oligemic sites in the rostral M3-MCA perfusion zones likely affect the white matter deep to Broca’s area, the uncinate fasiculus, the premotor cortex, and the facial portion of the primary motor cortex.
4. The combination of a focal 50-60% stenosis of the proximal right cervical ICA combined with incomplete circle of Willis has shifted the watershed zone to the anterior insular and lateral orbitofrontal areas (end of the line watershed oligemic pattern), which likely contributes to the reduced CT density in these areas.
5. There is a greater than 2 cm suspicious nodule in the left thyroid.