title: Performance of e-ASPECTS software in comparison to that of stroke physicians on assessing CT scans of acute ischemic stroke patients.
abstract: The Alberta Stroke Program Early CT score (ASPECTS) is an established 10-point quantitative topographic computed tomography scan score to assess early ischemic changes. We compared the performance of the e-ASPECTS software with those of stroke physicians at different professional levels.
  
  
  
  The baseline computed tomography scans of acute stroke patients, in whom computed tomography and diffusion-weighted imaging scans were obtained less than two hours apart, were retrospectively scored by e-ASPECTS as well as by three stroke experts and three neurology trainees blinded to any clinical information. The ground truth was defined as the ASPECTS on diffusion-weighted imaging scored by another two non-blinded independent experts on consensus basis. Sensitivity and specificity in an ASPECTS region-based and an ASPECTS score-based analysis as well as receiver-operating characteristic curves, Bland-Altman plots with mean score error, and Matthews correlation coefficients were calculated. Comparisons were made between the human scorers and e-ASPECTS with diffusion-weighted imaging being the ground truth. Two methods for clustered data were used to estimate sensitivity and specificity in the region-based analysis.
  
  
  
  In total, 34 patients were included and 680 (34 × 20) ASPECTS regions were scored. Mean time from onset to computed tomography was 172 ± 135 min and mean time difference between computed tomographyand magnetic resonance imaging was 41 ± 31 min. The region-based sensitivity (46.46% [CI: 30.8;62.1]) of e-ASPECTS was better than three trainees and one expert (p ≤ 0.01) and not statistically different from another two experts. Specificity (94.15% [CI: 91.7;96.6]) was lower than one expert and one trainee (p < 0.01) and not statistically different to the other four physicians. e-ASPECTS had the best Matthews correlation coefficient of 0.44 (experts: 0.38 ± 0.08 and trainees: 0.19 ± 0.05) and the lowest mean score error of 0.56 (experts: 1.44 ± 1.79 and trainees: 1.97 ± 2.12).
  
  
  
  e-ASPECTS showed a similar performance to that of stroke experts in the assessment of brain computed tomographys of acute ischemic stroke patients with the Alberta Stroke Program Early CT score method.
authors.affiliation: Department of Neuroradiology, University Hospital Heidelberg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Herweh
authors.affiliation: Department of Neurology, University Hospital Heidelberg, Germany.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Ringleb
authors.affiliation: Institute of Medical Biometry and Informatics, University of Heidelberg, Germany.
authors.forename: Geraldine
authors.initials: G
authors.lastname: Rauch
authors.affiliation: Centre for Statistics in Medicine, University of Oxford, United Kingdom.
authors.forename: Steven
authors.initials: S
authors.lastname: Gerry
authors.affiliation: Department of Neuroradiology, University Hospital Heidelberg, Germany.
authors.forename: Lars
authors.initials: L
authors.lastname: Behrens
authors.affiliation: Department of Neuroradiology, University Hospital Heidelberg, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Möhlenbruch
authors.affiliation: Department of Neurology, University Hospital Heidelberg, Germany.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Gottorf
authors.affiliation: Department of Neurology, University Hospital Heidelberg, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Richter
authors.affiliation: Department of Neurology, University Hospital Heidelberg, Germany.
authors.forename: Simon
authors.initials: S
authors.lastname: Schieber
authors.affiliation: Department of Neurology, University Hospital Heidelberg, Germany simon.nagel@med.uni-heidelberg.de.
authors.forename: Simon
authors.initials: S
authors.lastname: Nagel
mesh_terms: D000416:Alberta; D002545:Brain Ischemia / Q000000981:diagnostic imaging*; D002983:Clinical Competence; D003951:Diagnostic Errors; D038524:Diffusion Magnetic Resonance Imaging; D006801:Humans; D000069550:Machine Learning; D010363:Pattern Recognition, Automated; D010820:Physicians; D011446:Prospective Studies; D012372:ROC Curve; D012189:Retrospective Studies; D012984:Software; D020521:Stroke / Q000000981:diagnostic imaging*; D013997:Time Factors; D014057:Tomography, X-Ray Computed
keywords: Alberta Stroke Program Early CT score; computed tomography; ischemic stroke; machine learning