Automated CT Perfusion Prediction of Large Vessel Acute Stroke from Intracranial Atherosclerotic Disease

Abstract

Background and Purpose: We have observed that large vessel occlusion acute strokes (LVOS) due to intracranial atherosclerotic disease (ICAD) present with more benign CT perfusion (CTP) profiles, which we presume to potentially represent enhanced collateralization compared to embolic LVOS. We aim to determine if CTP profiles can predict ICAD in LVOS. Methods: Retrospective review of a prospectively collected interventional stroke database from September 2010 to March 2015. Patients with intracranial ICA/MCA-M1/M2 occlusions and CTP were dichotomized into ICAD versus non-ICAD etiologies. Ischemic core (relative cerebral blood flow < 30%) and hypoperfusion volumes were estimated by automated CTP. Results: A total of 250 patients met the inclusion criteria, comprised of 21 (8%) ICAD and 229 non-ICAD etiologies. Baseline characteristics were similar between groups, except for higher HbA1c levels (p < 0.01), LDL cholesterol (p < 0.01), systolic blood pressure (p < 0.01), and lower rate of atrial fibrillation (p < 0.01) in ICAD patients. There were no significant differences in volumes of baseline ischemic core (p = 0.54) among groups. ICAD patients had smaller Tmax > 4 s, Tmax > 6 s, and Tmax > 10 s absolute lesions, and a higher ratio of Tmax > 4 s/Tmax > 6 s volumes (median 2 [1.6–2.3] vs. 1.6 [1.4–2.0]; p = 0.02). A Tmax > 4 s/Tmax > 6 s ratio ≥2 showed specificity = 73%/sensitivity = 52% for ICAD and was observed in 47.6% of ICAD versus 26.1% of non-ICAD patients (p = 0.07). Clinical outcomes were comparable amongst groups. Multivariate logistic regression revealed that Tmax > 4 s/Tmax > 6 s ratio ≥2 (OR 3.75, 95% CI 1.05–13.14, p = 0.04), higher LDL cholesterol (OR 1.1, 95% CI 1.01–1.03, p = 0.01), and higher systolic pressure (OR 1.03, 95% CI 1.01–1.04, p = 0.01) were independently associated with ICAD. Conclusion: An automated CTP Tmax > 4 s/Tmax > 6 s ratio ≥2 profile was found independently associated with underlying ICAD LVOS.

Endovascular Treatment of Large Vessel Occlusion Strokes Due to Intracranial Atherosclerotic Disease

“…[42][43][44] A Tmax profile of Tmax >4 seconds/Tmax >6 seconds ratio ≥2 on CT perfusion reflects good collaterals and is also suggestive of ICAD-related LVO. 45 As compared to "non-tapered" occlusions (such as those demonstrating a meniscus, a flat-edged cutoff, or a tram-track sign), "tapered" occlusions with a jet-like, pencil-tip-like, or line-linked contrast filling appearance are associated with higher chances of underlying ICAD on CTA or DSA. 46,47…”

Intra-Arterial Glycoprotein IIb/IIIa Inhibitor Treatment for Symptomatic Intracranial Atherosclerotic Stenosis Presenting as Large Vessel Occlusions

“…Symptomatic intracranial hemorrhage was defined as any intracranial hemorrhage that caused neurological deterioration and a ≥ 4-point increase in the NIHSS score. The final angiogram was used to assess reperfusion status according to the modified treatment in cerebral infarction (m-TICI) scale, and successful reperfusion was considered an m-TICI grade of 2b or 3 [ 17 ]. A stroke neurologist evaluated patients’ neurological function within 24 hours of treatment.…”

Intracranial atherosclerotic disease mechanistic subtypes drive hypoperfusion patterns

“…We sought to derive hypoperfusion profiles from MR (n = 35) or CT perfusion (n = 7) delays at varying T max thresholds: T max > 4 s, T max > 6 s, T max > 8 s, and T max > 10 s. To identify an optimal imaging TA B L E 1 Core infarct, perfusion delay volumes, and target mismatch volumes in intracranial atherosclerotic stenosis infarct patterns Volume (ml) parameters delineating each of the ICAD phenotypes, we also calculated various ratios as well as total relative difference in the volume delays. 10 And similar to prior studies, a target mismatch was set as hypoperfusion volume (along the four aforementioned T max perfusion delays) subtracted by core infarct volume >15 ml. 8…”

“…9 For the predominant infarct pattern seen on diffusion-weighted imag- parameters delineating each of the ICAD phenotypes, we also calculated various ratios as well as total relative difference in the volume delays. 10 And similar to prior studies, a target mismatch was set as hypoperfusion volume (along the four aforementioned T max perfusion delays) subtracted by core infarct volume >15 ml. 8…”