Case Notes
History
42 year-old male with right sided numbness and neck pain; history of seizures and hypertensionExam
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
CT HeadThere is evidence of a left high-cervical ICA dissection. There is very subtle edema in the left hippocampus.
MRA Head and Neck
There are changes consistent with left high-cervical and vertical intapetrous ICA dissection. There is a short segment with non-filling of the genu segment of the ICA likely representing occlusion. However, the left ICA becomes patent in the horizontal, intrapetrous segment and beyond reflecting patent EC-IC collateralization.
Focal areas of absent MRA signal (consistent with down-stream thromboemboli) were evident in the proximal right ACA, the proximal left PCA, and the left MCA at the M2 trunk division (affecting flow into both the superior and inferior MCA perfusion zones).