Perfusion CT in Acute Stroke: A Comprehensive Analysis of Infarct and Penumbra

Bivard, Andrew; Levi, Christopher; Spratt, Neil J; Parsons, Mark

doi:10.1148/radiol.12120971

Cited by 233 publications

(218 citation statements)

References 21 publications

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“…Perhaps most important, this study used different postprocessing software to SWIFT PRIME, and it has been demonstrated that the optimal thresholds to define ischemia are specific to the software and postprocessing method utilized. 12 Therefore, the CBF thresholds from our study may well be different when applied to other software. Nonetheless, we propose that the principle demonstrated in this analysis would apply to other software if tested on our data set.…”

Section: Discussionmentioning

confidence: 93%

“…12 ROC curve analysis was used to test the predictive performance of CTP in relation to the DWI infarct core. The DWI image was considered to be the "true" lesion, and the pixels where the DWI lesion and perfusion CT lesion overlapped were considered to be "true positive."…”

Section: Discussionmentioning

confidence: 99%

“…Baseline National Institutes of Health Stroke Scale (median, 15; interquartile range [IQR], [11][12][13][14][15][16][17][18][19], age (median, 65; IQR, 59-80), and time to intravenous treatment (median, 153 minutes; IQR, 82-315) were well matched (all p > 0.05). Despite similar baseline CTP ischemic core volumes using the previously validated measure (relative cerebral blood flow [rCBF], <30%), thrombectomy patients had a smaller median 24-hour infarct core of 17.3ml (IQR, 11.3-32.8) versus 24.3ml (IQR, 16.7-42.2; p 5 0.011) in alteplase-treated controls.…”

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confidence: 95%

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Ischemic core thresholds change with time to reperfusion: A case control study

Bivard

Kleinig

Miteff

et al. 2017

Annals of Neurology

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Introduction: We aimed to identify whether acute ischemic stroke patients with known complete reperfusion after thrombectomy had the same baseline computed tomography perfusion (CTP) ischemic core threshold to predict infarction as thrombolysis patients with complete reperfusion. Methods: Patients who underwent thrombectomy were matched by age, clinical severity, occlusion location, and baseline perfusion lesion volume to patients who were treated with intravenous alteplase alone from the International Stroke Perfusion Imaging Registry. A pixel-based analysis of coregistered pretreatment CTP and 24-hour diffusionweighted imaging (DWI) was then undertaken to define the optimum CTP thresholds for the ischemic core. Results: There were 132 eligible thrombectomy patients and 132 matched controls treated with alteplase alone. Baseline National Institutes of Health Stroke Scale (median, 15; interquartile range [IQR], 11-19), age (median, 65; IQR, 59-80), and time to intravenous treatment (median, 153 minutes; IQR, 82-315) were well matched (all p > 0.05). Despite similar baseline CTP ischemic core volumes using the previously validated measure (relative cerebral blood flow [rCBF], <30%), thrombectomy patients had a smaller median 24-hour infarct core of 17.3ml (IQR, 11.3-32.8) versus 24.3ml (IQR, 16.7-42.2; p 5 0.011) in alteplase-treated controls. As a result, the optimal threshold to define the ischemic core in thrombectomy patients was rCBF <20% (area under the curve [AUC], 0.89; 95% CI, 0.84, 0.94), whereas in alteplase controls the optimal ischemic core threshold remained rCBF <30% (AUC, 0.83; 95% CI, 0.77, 0.85). Interpretation: Thrombectomy salvaged tissue with lower CBF, likely attributed to earlier reperfusion. For patients who achieve rapid reperfusion, a stricter rCBF threshold to estimate the ischemic core should be considered.

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Section: Discussionmentioning

confidence: 93%

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 95%

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Ischemic core thresholds change with time to reperfusion: A case control study

Bivard

Kleinig

Miteff

et al. 2017

Annals of Neurology

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“…21 We avoided using rigid quantitative perfusion thresholds for the definition of the ischemic core since postprocessing methods vary widely among manufactures, 22 and since there are currently no operationally defined and universally accepted thresholds. 17 We therefore manually segmented the perfusion deficit on every axial slice using the OsiriX closed polygon tool to create an ROI; thus, the extent of the perfusion deficit could be evaluated by comparison with the contralateral hemisphere. The infarct volume was then calculated using the OsiriX volume calculation tool.…”

Section: Computed Tomography Perfusion Image Processing and Analysismentioning

confidence: 99%

Predictive Value of the Velocity of Collateral Filling in Patients with Acute Ischemic Stroke

Beyer¹,

Baumgarten

Thierfelder³

et al. 2014

J Cereb Blood Flow Metab

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The velocity of collateral filling can be assessed in dynamic time-resolved computed tomography (CT) angiographies and may predict initial CT perfusion (CTP) and follow-up lesion size. We included all patients with an M1 ± internal carotid artery (ICA) occlusion and follow-up imaging from an existing cohort of 1791 consecutive patients who underwent multimodal CT for suspected stroke. The velocity of collateral filling was quantified using the delay of time-to-peak (TTP) enhancement of the M2 segment distal to the occlusion. Cerebral blood volume (CBV) and mean transit time (MTT)-CBV mismatch were assessed in initial CTP. Follow-up lesion size was assessed by magnetic resonance imaging (MRI) or non-enhanced CT (NECT). Multivariate analyses were performed to adjust for extent of collateralization and type of treatment. Our study comprised 116 patients. Multivariate analysis showed a short collateral blood flow delay to be an independent predictor of a small CBV lesion (P o 0.001) and a large relative mismatch (P o 0.001) on initial CTP, of a small follow-up lesion (P o 0.001), and of a small difference between initial CBV and follow-up lesion size (P = 0.024). Other independent predictors of a small lesion on follow-up were a high morphologic collateral grade (P = 0.001), lack of an additional ICA occlusion (P = 0.009), and intravenous thrombolysis (P = 0.022). Fast filling of collaterals predicts initial CTP and follow-up lesion size and is independent of extent of collateralization.

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“…From this cohort, we included all patients with complete occlusion of the middle cerebral artery in the M1 segment, with or without an occlusion of the internal carotid artery, on both conventional and dynamic CTA. We excluded patients with the following: 1) Incomplete or missing whole-brain CTP raw datasets 2) Missing follow-up NECT or MR imaging acquired at least 1 day after initial CT perfusion imaging 19 3) Nondiagnostic quality of conventional CTA or dynamic CTA.…”

Section: Study Design and Populationmentioning

confidence: 99%