Case Notes
History
81 year old female presenting with acute onset mental status change, dizziness, nausea, and gait imbalance.Exam
Head MR Diffusion sequences (with DWI & ADC maps)
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 stroke protocol CTA1. Distal segment basilar artery partially occlusive acute thrombosis is present with mainly circle of Willis collateral to distal basilar tip and PCA trunks. Thus, there is filling of all pial arteries, although limited on the left.
2. There is significantly reduced CT density in the venocapillary pool in the subcortical mesial occipital white matter bilaterally (dense ischemic core). Findings are most consistent with ischemic injury associated with the initial thromboembolic event. Currently there has been significant recanalization of the distal P4 arteries (better on the right) and partial clot lysis in the distal basilar artery. The depth and duration of the initial ischemic insult resulted in deep white matter occipital stroke.
2. Limited filling the left PICA resulting in completed stroke involving the mesial (caudal) cerebellum (dense ischemic core) and lesser ischemic changes in the remaining left lateral cerebellum (likely in the ischemic penumbra).