Case Notes
History
71 year old male presenting with acute onset slurred or muffled speech, no weakness, was able to understand speech, with no loss of consciousness.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. Prior occlusion of the posterior M3 trunk off the superior division Lt MCA, which has good pial collateral preventing extension of the stroke to most of the posterior superior division perfusion zone.
2. There is acute thrombus in single artery (artery to the central sulcus). The affected perfusion zone for this artery is much smaller than its’ full (normal) perfusion territory, which indicates there has been substantial retrograde pial collateralization from the A4 (ACA) pial vessels. However, there remains a small pial collateral gap in the mid-insula and the adjacent frontoparietal opercular cortex. In this case, the affected area includes the tongue part of the primary facial motor area, which correlates with the patients presenting symptom of dysarthria.
3. The improved CT density in the venocapillary pool is a good indication that the extent of final stroke-zone will remain quite small.