More specifically, patients presenting with suspicious signs on noncontrast CT such as hyperdense middle cerebral artery sign with a clear etiology for the LVO such as new onset atrial fibrillation may benefit from proceeding directly to angiography, although prospective data are limited in this regard [55]. Cerebrovascular Diseases-Stroke CT Head Perfusion With IV Contrast Within the initial 6-hour window of presentation of an acute stroke, CTP of the head is usually not necessary as an initial examination; conversely, delay, created by obtaining and analyzing CTP in the setting of a known LVO patient who is a clear EVT candidate, may be harmful [13,56]. In contrast, determining eligibility for EVT for anterior circulation strokes due to LVO confirmed on CTA presenting in the extended window of 6 to 24 hours may require or be determined by CTP or MR perfusion imaging in some cases [46,57]. Although a major RCT showing benefit of EVT 6 to 24 hours after onset permitted eligibility based on DWI-MRI or CTP [46], the rapidity of diagnosis afforded by CTP is a strongly relevant clinical consideration in this situation in most settings. CT Head With IV Contrast There is no relevant literature to support the use of contrast-enhanced CT of the head in the evaluation of ischemic stroke. CT Head Without and With IV Contrast There is no relevant literature to support the use of CT of the head without and with IV contrast in the evaluation of ischemic stroke. CTA Head With IV Contrast CTA of the head is the most rapid means of assessment of the intracranial vasculature for LVO in the setting of stroke. CTA of the head has a high sensitivity and specificity for the detection of intracranial LVO [60]. Stroke, possibly due to LVO, is a true medical emergency in which the rapidity of diagnosis afforded by CTA is a strongly relevant clinical consideration.
Cerebrovascular Diseases Stroke and Stroke Related Conditions PCAs. More specifically, patients presenting with suspicious signs on noncontrast CT such as hyperdense middle cerebral artery sign with a clear etiology for the LVO such as new onset atrial fibrillation may benefit from proceeding directly to angiography, although prospective data are limited in this regard [55]. Cerebrovascular Diseases-Stroke CT Head Perfusion With IV Contrast Within the initial 6-hour window of presentation of an acute stroke, CTP of the head is usually not necessary as an initial examination; conversely, delay, created by obtaining and analyzing CTP in the setting of a known LVO patient who is a clear EVT candidate, may be harmful [13,56]. In contrast, determining eligibility for EVT for anterior circulation strokes due to LVO confirmed on CTA presenting in the extended window of 6 to 24 hours may require or be determined by CTP or MR perfusion imaging in some cases [46,57]. Although a major RCT showing benefit of EVT 6 to 24 hours after onset permitted eligibility based on DWI-MRI or CTP [46], the rapidity of diagnosis afforded by CTP is a strongly relevant clinical consideration in this situation in most settings. CT Head With IV Contrast There is no relevant literature to support the use of contrast-enhanced CT of the head in the evaluation of ischemic stroke. CT Head Without and With IV Contrast There is no relevant literature to support the use of CT of the head without and with IV contrast in the evaluation of ischemic stroke. CTA Head With IV Contrast CTA of the head is the most rapid means of assessment of the intracranial vasculature for LVO in the setting of stroke. CTA of the head has a high sensitivity and specificity for the detection of intracranial LVO [60]. Stroke, possibly due to LVO, is a true medical emergency in which the rapidity of diagnosis afforded by CTA is a strongly relevant clinical consideration.