Case Notes
History
64 year old male on aspirin and Plavix presenting presenting with acute gait difficulty and left visual field problems.Exam
CTA of the Neck
This part of the CTA is performed after the second bolus of contrast, and therefore has dense contrast in both the arteries and the veins related to recirculation plus twice the contrast load. The CTA neck is performed in conjunction with the delayed post contrast head CTA for assessment of the CT-density in the parenchymal venocapillary pool.
Purpose
1. Define sites of any and all arterial thromboses or flow-limiting, high-grade stenosis, or tandem stenoses with lesser degrees of luminal narrowing, but are included within the same arterial circuit;
2. Characterize the features of the stenotic/occluded arterial segment (NASCET, assess length of stenosis/occlusion, intimal dehiscence, atherosclerotic vs inflammatory basis, etc.);
3. Determine whether there is effective collateral around any occluded segment;
4. Assess the presence of effective EC-IC collateral in cases of extradural ICA occlusion.
This part of the CTA is performed after the second bolus of contrast, and therefore has dense contrast in both the arteries and the veins related to recirculation plus twice the contrast load. The CTA neck is performed in conjunction with the delayed post contrast head CTA for assessment of the CT-density in the parenchymal venocapillary pool.
Purpose
1. Define sites of any and all arterial thromboses or flow-limiting, high-grade stenosis, or tandem stenoses with lesser degrees of luminal narrowing, but are included within the same arterial circuit;
2. Characterize the features of the stenotic/occluded arterial segment (NASCET, assess length of stenosis/occlusion, intimal dehiscence, atherosclerotic vs inflammatory basis, etc.);
3. Determine whether there is effective collateral around any occluded segment;
4. Assess the presence of effective EC-IC collateral in cases of extradural ICA occlusion.
Prior Study
Non Contrast Head CTThere is focal hyperdensity in the distal basilar apex consistent with acute thrombus.
There is no discernable cytogenic edema, and certainly no obvious edema to confirm stroke outside the treatment window.
CT Perfusion
1. Short segment acute thrombus is evident on the included head CTA located in the distal basilar apex.
2. Delayed PCA filling (prolonged TTP) is related to retrograde PCA filling from the circle of Willis.
3. Chronic reduced CBV is evident in the caudal Rt. cerebellum, but no discernable hyperacute stroke is evident.