Case Notes
History
59 year old male with COPD who developed tachycardia requiring therapy. Two days later he developed Rt. sided weakness, pupillary dysfunction, and slurred speech. Shortly thereafter, he became somnolent and unresponsive.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 stensoses with of lesser degrees luminal narrowing, but are included in the same arterial circuit;
2. Characterize the features of each stenotic/occluded arterial segment (NASCET, assess length of stenosis/occlusion, intimal dehiscence, atherosclerotic vs inflammatory basis, etc.)
3. Determine whether there is any persistent antegrade flow past the stenosis, but if not, is there 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 stensoses with of lesser degrees luminal narrowing, but are included in the same arterial circuit;
2. Characterize the features of each stenotic/occluded arterial segment (NASCET, assess length of stenosis/occlusion, intimal dehiscence, atherosclerotic vs inflammatory basis, etc.)
3. Determine whether there is any persistent antegrade flow past the stenosis, but if not, is there effective collateral around any occluded segment;
4. Assess the presence of effective EC-IC collateral in cases of extradural ICA occlusion;
Prior Study
CT Head1. Hyperacute basilar and left intradural vertebral artery thromboses with multicentric both arterial and watershed strokes involving multiple posterior fossa arteries, as described above.
2. There is early mass effect including compression of the 4th ventricle, effacement of prepontine cisterns, and clear evidence of early upward transtentorial herniation.
3. Focal lesion within the deep central left cerebellum is likely a site of hemorrhagic conversion with very acute hematoma.
CT Perfusion
1. The TTP, CBF, & CBV changes consistent with completed infarctions in both SCA’s, the left AICA, the left PICA, the right cerebellar watershed zones, and possibly the left pons.
2. Absent MTT signal (out of scale sign) indicates virtually no transcapillary blood flow to generate MTT data. This is can occur with either sequestered infarction, or hemorrhagic transformation, or both. Differentiation between these two stroke complications is best exhibited on the MR susceptibility sequence.
3. CTA head (included with our CT perfusion protocol) demonstrates patency of the left intradural vertebral artery and of the caudal basilar artery at this time, despite the CT-hyperdensity seen on the noncontrast CT head .
4. There is an old infarct with an encephalomalacic defect in the left temporal lobe (PCA-P3 segment perfusion zone).