title: Multimodal CT provides improved performance for lacunar infarct detection.
abstract: OBJECTIVE
  Lacunar infarcts account for approximately 25% of acute ischemic strokes. Compared with NCCT alone, the addition of CTP improves sensitivity for detection of infarcts overall. Our aim was to systematically evaluate the diagnostic benefit and interobserver reliability of an incremental CT protocol in lacunar infarction.
  
  
  METHODS
  Institutional review board approval and patient consent were obtained. One hundred sixty-three patients presenting with a lacunar syndrome ≤4.5 hours from symptom onset were enrolled. Images were reviewed incrementally by 2 blinded readers in 3 separate sessions (NCCT only, NCCT/CTA, and NCCT/CTA/CTP). Diagnostic confidence was recorded on a 6-point scale with DWI/ADC as a reference. Logistic regression analysis calculated differences between actual and observed diagnoses, adjusted for confidence. Predictive effects of observed diagnostic accuracy and confidence score were quantified with the entropy r(2) value. Sensitivity, specificity, and confidence intervals were calculated accounting for multiple readers. Receiver operating characteristic analyses were compared among diagnostic strategies. Interobserver agreement was established with Cohen κ statistic.
  
  
  RESULTS
  The final study cohort comprised 88 patients (50% male). DWI/ADC-confirmed lacunar infarction occurred in 59/88 (67%) with 36/59 (61%) demonstrating a concordant abnormal finding on CTP. Sensitivity for definite or probable presence of lacunar infarct increased significantly from 9.3% to 42.4% with incremental protocol use, though specificity was unchanged (range, 91.9%-95.3%). The observed diagnosis was significantly related to the actual diagnosis after adjusting for CTP confidence level (P = .04) and was 5.1 and 2.4 times more likely to confirm lacunar infarct than NCCT or CTA source images. CTP area under the curve (0.77) was significantly higher than that of CTA source images (0.68, P = .006) or NCCT (0.55, P < .001).
  
  
  CONCLUSIONS
  CTP offers an improved diagnostic benefit over NCCT and CTA for the diagnosis of lacunar infarction.
authors.affiliation: From the Department of Radiology (T.D.), Cambridge University Hospitals NHS Foundation Trust, Addenbrooke's Hospital, Cambridge, UK.
authors.forename: T
authors.initials: T
authors.lastname: Das
authors.affiliation: Departments of Medical Imaging (F.S., T.H., R.I.A., S.P.S., L.Z.).
authors.forename: F
authors.initials: F
authors.lastname: Settecase
authors.affiliation: Neurology (M.B.), Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada University of Toronto (M.B., T.H., S.P.S., R.I.A.), Toronto, Ontario, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Boulos
authors.affiliation: Departments of Medical Imaging (F.S., T.H., R.I.A., S.P.S., L.Z.) University of Toronto (M.B., T.H., S.P.S., R.I.A.), Toronto, Ontario, Canada.
authors.forename: T
authors.initials: T
authors.lastname: Huynh
authors.affiliation: Department of Neurology (C.D.d.), University of Calgary, Calgary Stroke Program, Foothills Medical Centre, Calgary, Alberta, Canada.
authors.forename: C D
authors.initials: CD
authors.lastname: d'Esterre
authors.affiliation: Departments of Medical Imaging (F.S., T.H., R.I.A., S.P.S., L.Z.) University of Toronto (M.B., T.H., S.P.S., R.I.A.), Toronto, Ontario, Canada.
authors.forename: S P
authors.initials: SP
authors.lastname: Symons
authors.affiliation: Departments of Medical Imaging (F.S., T.H., R.I.A., S.P.S., L.Z.).
authors.forename: L
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Departments of Medical Imaging (F.S., T.H., R.I.A., S.P.S., L.Z.) University of Toronto (M.B., T.H., S.P.S., R.I.A.), Toronto, Ontario, Canada. Richard.aviv@sunnybrook.ca.
authors.forename: R I
authors.initials: RI
authors.lastname: Aviv
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002533:Cerebral Angiography / Q000379:methods*; D015331:Cohort Studies; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D015588:Observer Variation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D059409:Stroke, Lacunar / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*