title: CT perfusion source images improve identification of early ischaemic change in hyperacute stroke.
abstract: CT perfusion scanning produces dynamic contrast-enhanced brain images, but to generate and interpret the colour maps of cerebral perfusion from these source images requires specialist neuroimaging knowledge. We hypothesized that physicians without such training might still utilise the CT perfusion source images (CTPSI) to diagnose early ischaemic change. Fifteen patients had cerebral non-contrast CT (NCCT) and perfusion CT within 6 hours of hemispheric stroke onset. We tested 15 non-stroke clinicians and radiology trainees, plus three experts, in assessing the presence and extent of early ischaemic change on NCCT versus CTPSI. Day 5-7 CT or MRI was used as the gold standard. Agreement with follow-up imaging was poor for both detection, and extent of early ischaemic change on NCCT (kappa = 0.01-0.11). There was a marked improvement in agreement for both the presence and extent of early ischaemic change on CTPSI (kappa = 0.67-0.83). CTPSI were much more accurate than NCCT in identifying acute ischaemic change. 'Less expert' users accurately identified major early ischaemic change on acute CTPSI. These findings suggest that such physicians might utilise CTPSI to screen potential thrombolysis candidates.
authors.affiliation: Department of Neurology, John Hunter Hospital and Hunter Medical Research Institute, University of Newcastle, Locked Bag No. 1, Hunter Region Mail Centre, NSW 2310, Australia.
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Pepper
authors.forename: Mark W
authors.initials: MW
authors.lastname: Parsons
authors.forename: Grant A
authors.initials: GA
authors.lastname: Bateman
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Levi
mesh_terms: D000208:Acute Disease; D000368:Aged; D002545:Brain Ischemia / Q000175:diagnosis / Q000000981:diagnostic imaging*; D001931:Brain Mapping; D002533:Cerebral Angiography; D002560:Cerebrovascular Circulation / Q000502:physiology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D020244:Infarction, Middle Cerebral Artery / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D020521:Stroke / Q000175:diagnosis / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed