Automated CT Perfusion Ischemic Core Volume and Noncontrast CT ASPECTS (Alberta Stroke Program Early CT Score): Correlation and Clinical Outcome Prediction in Large Vessel Stroke.

The semiquantitative noncontrast CT Alberta Stroke Program Early CT Score (ASPECTS) and RAPID automated computed tomography (CT) perfusion (CTP) ischemic core volumetric measurements have been used to quantify infarct extent. We aim to determine the correlation between ASPECTS and CTP ischemic core, evaluate the variability of core volumes within ASPECTS strata, and assess the strength of their association with clinical outcomes. Review of a prospective, single-center database of consecutive thrombectomies of middle cerebral or intracranial internal carotid artery occlusions with pretreatment CTP between September 2010 and September 2015. CTP was processed with RAPID software to identify ischemic core (relative cerebral blood flow<30% of normal tissue). Three hundred and thirty-two patients fulfilled inclusion criteria. Median age was 66 years (55-75), median ASPECTS was 8 (7-9), whereas median CTP ischemic core was 11 cc (2-27). Median time from last normal to groin puncture was 5.8 hours (3.9-8.8), and 90-day modified Rankin scale score 0 to 2 was observed in 54%. The correlation between CTP ischemic core and ASPECTS was fair (R=-0.36; P<0.01). Twenty-six patients (8%) had ASPECTS <6 and CTP core ≤50 cc (37% had modified Rankin scale score 0-2, whereas 29% were deceased at 90 days). Conversely, 27 patients (8%) had CTP core >50 cc and ASPECTS ≥6 (29% had modified Rankin scale 0-2, whereas 21% were deceased at 90 days). Moderate correlations between ASPECTS and final infarct volume (R=-0.42; P<0.01) and between CTP ischemic core and final infarct volume (R=0.50; P<0.01) were observed; coefficients were not significantly influenced by the time from stroke onset to presentation. Multivariable regression indicated ASPECTS ≥6 (odds ratio 4.10; 95% confidence interval, 1.47-11.46; P=0.01) and CTP core ≤50 cc (odds ratio 3.86; 95% confidence interval, 1.22-12.15; P=0.02) independently and comparably predictive of good outcome. There is wide variability of CTP-derived core volumes within ASPECTS strata. Patient selection may be affected by the imaging selection method.

Haussen DC ，Dehkharghani S ，Rangaraju S ，Rebello LC ，Bouslama M ，Grossberg JA ，Anderson A ，Belagaje S ，Frankel M ，Nogueira RG ... -  《-》

Noncontrast Computed Tomography e-Stroke Infarct Volume Is Similar to RAPID Computed Tomography Perfusion in Estimating Postreperfusion Infarct Volumes.

Bouslama M ，Ravindran K ，Harston G ，Rodrigues GM ，Pisani L ，Haussen DC ，Frankel MR ，Nogueira RG ... -  《-》

Single-Centre Experience with Patients Selection for Mechanical Thrombectomy Based on Automated Computed Tomography Perfusion Analysis-A Comparison with Computed TomographyCT Perfusion Thrombectomy Trials.

In randomized clinical trials, mechanical thrombectomy (MT) was proved to be a highly effective treatment of acute ischemic stroke which improved clinical outcomes. Some of the trials used automated computed tomography perfusion (CTP) analysis for selection of participants. We present a single-center experience with CTP selection and comparison with CTP trials. Data of consecutive MT patients (from January 2016 to December 2017) were retrospectively reviewed. All patients with multiphase CT angiography confirmed the presence of anterior circulation large vessel occlusion/s in the intracranial internal carotid artery and/or middle cerebral artery (M1 or M2) and with admission brain CTP analyzed by RAPID software were included into the analysis. Sixty-two patients fulfilled the inclusion criteria (mean age was 70.1 ± 13.6 years, females 48.5%). At baseline, National Institutes of Health Stroke Scale score was 16 (IQR = 13-20), Alberta Stroke Program Early CT Score (ASPECTS) was 8 (IQR = 7-9), CTP core volume was 20 mL (IQR = 2-36), and CTP penumbra volume was 145.5 mL (IQR = 107-184). Time from stroke onset to imaging was 1 hour 32 minutes, time from stroke onset to reperfusion was 3 hours 50 minutes, and median time from CT to reperfusion was 1 hour 56 minutes. Modified thrombolysis in cerebral infarction 2b/3 was achieved in 42 patients (67.7%). Twenty-three patients (37%) had modified Rankin scale 0-2 at 90 days. Our analysis of CTP-selected patients for MT supports clinical applicability of automated CTP analysis into everyday clinical practice.

Vanicek J ，Cimflova P ，Bulik M ，Jarkovsky J ，Prelecova V ，Szeder V ，Volny O ... -  《-》

Automated CT Perfusion Imaging Versus Non-contrast CT for Ischemic Core Assessment in Large Vessel Occlusion.

Tsang ACO ，Lenck S ，Hilditch C ，Nicholson P ，Brinjikji W ，Krings T ，Pereira VM ，Silver FL ，Schaafsma JD ... -  《-》

Noncontrast CT versus Perfusion-Based Core Estimation in Large Vessel Occlusion: The Blood Pressure after Endovascular Stroke Therapy Study.

The 2018 AHA guidelines recommend perfusion imaging to select patients with acute large vessel occlusion (LVO) for thrombectomy in the extended window. However, the relationship between noncontrast CT and CT perfusion imaging has not been sufficiently characterized >6 hours after last known normal (LKN). From a multicenter prospective cohort of consecutive adults who underwent thrombectomy for anterior LVO 0-24 hours after LKN, we correlated baseline core volume (rCBF < 30%) and the Alberta Stroke Program Early CT Scale (ASPECTS) score. We compared perfusion findings between patients with an unfavorable ASPECTS (<6) against those with a favorable ASPECTS (≥6), and assessed findings over time. Of 485 enrolled patients, 177 met inclusion criteria (median age: 69 years, interquartile range [IQR: 57-81], 49% female, median ASPECTS 8 [IQR: 6-9], median core 10 cc [IQR: 0-30]). ASPECTS and core volume moderately correlated (r = -.37). A 0 cc core was observed in 54 (31%) patients, 70% of whom had ASPECTS <10. Of the 28 patients with ASPECTS <6, 3 (11%) had a 0 cc core. After adjustment for age and stroke severity, there was a lower ASPECTS for every 1 hour delay from LKN (cOR: 0.95, 95% confidence of interval [CI]: 0.91-1.00, P = .04). There was no difference in core (P = .51) or penumbra volumes (P = .87) across patients over time. In this multicenter prospective cohort of patients who underwent thrombectomy, one-third of patients had normal CTP core volumes despite nearly three quarters of patients showing ischemic changes on CT. This finding emphasizes the need to carefully assess both noncontrast and perfusion imaging when considering thrombectomy eligibility.

Siegler JE ，Messé SR ，Sucharew H ，Kasner SE ，Mehta T ，Arora N ，Starosciak AK ，De Los Rios La Rosa F ，Barnhill NR ，Mistry AM ，Patel K ，Assad S ，Tarboosh A ，Dakay K ，Wagner J ，Bennett A ，Jagadeesan B ，Streib C ，Weber SA ，Chitale R ，Volpi JJ ，Mayer SA ，Yaghi S ，Jayaraman MV ，Khatri P ，Mistry EA ... -  《-》