Computed Tomography Perfusion Improves Diagnostic Accuracy in Acute Posterior Circulation Stroke

Abstract

Background and Purpose: Computed tomography perfusion (CTP) has a high diagnostic value in the detection of acute ischemic stroke in the anterior circulation. However, the diagnostic value in suspected posterior circulation (PC) stroke is uncertain, and whole brain volume perfusion is not yet in widespread use. We therefore studied the additional value of whole brain volume perfusion to non-contrast CT (NCCT) and CT angiography source images (CTA-SI) for infarct detection in patients with suspected acute ischemic PC stroke. Methods: This is a retrospective review of patients with suspected stroke in the PC in a database of our stroke center (n = 3,011) who underwent NCCT, CTA and CTP within 9 h after stroke onset and CT or MRI on follow-up. Images were evaluated for signs and pc-ASPECTS locations of ischemia. Three imaging models - A (NCCT), B (NCCT + CTA-SI) and C (NCCT + CTA-SI + CTP) - were compared with regard to the misclassification rate relative to gold standard (infarction in follow-up imaging) using the McNemar's test. Results: Of 3,011 stroke patients, 267 patients had a suspected stroke in the PC and 188 patients (70.4%) evidenced a PC infarct on follow-up imaging. The sensitivity of Model C (76.6%) was higher compared with that of Model A (21.3%) and Model B (43.6%). CTP detected significantly more ischemic lesions, especially in the cerebellum, posterior cerebral artery territory and thalami. Conclusions: Our findings in a large cohort of consecutive patients show that CTP detects significantly more ischemic strokes in the PC than CTA and NCCT alone.

Qualitative versus automatic evaluation of CT perfusion parameters in acute posterior circulation ischaemic stroke

“…Concordant to other studies, our findings confirmed that CTP in PC allows to detect significantly more ischaemic strokes than NCCT [4,5,39]. As NCCT presented low SE and ACC values, the addiction of CTP in the diagnostic work-up in our patients suspected of an ischaemic posterior circulation stroke significantly increased diagnostic ACC.…”

“…The diagnostic value of CTP in the posterior circulation has been little investigated with few evidences of its reliability and accuracy; moreover, the diagnostic effects of RAPID introduction in the evaluation of infratentorial ischaemic changes have not yet been clarified [3,4,[38][39][40]. To the best of our knowledge, these are the first reported instances of PC stroke patient selection using RAPID from European countries.…”

Perfusion computed tomography in posterior circulation stroke: predictors and prognostic implications of focal hypoperfusion

“…A subgroup analysis from the Dutch Acute Stroke Trial (DUST) showed that the addition of CTP increases the detection rate of early ischaemic changes in the posterior circulation compared to combinatory NCCT and CTA [7]. Another study found similar results, suggesting an increase of sensitivity for the detection of ischaemic lesions with the addition of CTP in CTbased imaging of acute vertebrobasilar stroke [6].…”

“…Few other studies have tested the performance of CTP in this stroke territory [6][7][8][9][10]14]. A subgroup analysis from the Dutch Acute Stroke Trial (DUST) showed that the addition of CTP increases the detection rate of early ischaemic changes in the posterior circulation compared to combinatory NCCT and CTA [7].…”

Posterior circulation stroke: machine learning-based detection of early ischemic changes in acute non-contrast CT scans

“…Ninth, only NCCT images were used for infarct prediction. Although computed tomographic perfusion imaging (CTP) may improve detection rates of posterior circulation ischemia [23], CTP images are difficult to interpret and can lead to false positive results [25]. Furthermore, the limitation to NCCT scans improves general applicability of the algorithm in clinical routine and retrospective studies, as not all hospitals perform CTP imaging in respective acute situations.…”