title: Intracranial aneurysms at MR angiography: effect of computer-aided diagnosis on radiologists' detection performance.
abstract: OBJECTIVE
  To retrospectively evaluate the effect of computer-aided detection (CAD) on radiologists' performance in detection of intracranial aneurysms with magnetic resonance (MR) angiography.
  
  
  METHODS
  The institutional review board approved this study and did not require patient informed consent. Fifty maximum intensity projection MR angiograms in 50 patients were used for observer performance study. The group included 22 patients (age range, 43-86 years; mean, 60.2 years; 6 men and 16 women) with intracranial aneurysms and 28 patients (age range, 32-80 years; mean, 58.8 years; 10 men and 18 women) without aneurysms. The MR angiograms were obtained with three-dimensional time-of-flight 1.5-T MR imaging. Fifteen radiologists, including eight neuroradiologists and seven general radiologists, participated in the observer performance test. They interpreted the angiograms first without and then with the aid of the computer output by using an automated computerized scheme. The observers' performance without and with the computer output was evaluated with receiver operating characteristic analysis.
  
  
  RESULTS
  For all 15 observers, average area under the receiver operating characteristic curve (A(z)) value for detection of aneurysms was increased significantly from 0.931 to 0.983 (P = .001) when they used the computer output. A(z) values for general radiologists and neuroradiologists increased from 0.894 to 0.983 (P = .022) and from 0.963 to 0.984 (P = .014), respectively. Improvement in the performance of general radiologists in terms of the A(z) value was much greater than that of neuroradiologists. Performance of general radiologists with CAD (A(z) = 0.983) slightly exceeded that of neuroradiologists without CAD (A(z) = 0.963) (P = .048).
  
  
  CONCLUSIONS
  CAD improved neuroradiologists' and general radiologists' performance for detection of intracranial aneurysms with MR angiography; improvement was greater for general radiologists than it was for neuroradiologists.
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556, Japan.
authors.forename: Toshinori
authors.initials: T
authors.lastname: Hirai
authors.forename: Yukunori
authors.initials: Y
authors.lastname: Korogi
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Arimura
authors.forename: Shigehiko
authors.initials: S
authors.lastname: Katsuragawa
authors.forename: Mika
authors.initials: M
authors.lastname: Kitajima
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamura
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yamashita
authors.forename: Kunio
authors.initials: K
authors.lastname: Doi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002983:Clinical Competence; D003936:Diagnosis, Computer-Assisted; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D002532:Intracranial Aneurysm / Q000175:diagnosis*; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012372:ROC Curve; D012189:Retrospective Studies; D018709:Statistics, Nonparametric