title: Do long radiology workdays affect nodule detection in dynamic CT interpretation?
abstract: OBJECTIVE
  A previous study demonstrated decreased diagnostic accuracy for finding fractures and decreased ability to focus on skeletal radiographs after a long working day. Skeletal radiographic examinations commonly have images that are displayed statically. The aim of this study was to investigate whether diagnostic accuracy for detecting pulmonary nodules on CT of the chest displayed dynamically would be similarly affected by fatigue.
  
  
  METHODS
  Twenty-two radiologists and 22 residents were given 2 tests searching CT chest sequences for a solitary pulmonary nodule before and after a day of clinical reading. To measure search time, 10 lung CT sequences, each containing 20 consecutive sections and a single nodule, were inspected using free search and navigation. To measure diagnostic accuracy, 100 CT sequences, each with 20 sections and half with nodules, were displayed at preset scrolling speed and duration. Accuracy was measured using receiver operating characteristic curve analysis. Visual strain was measured via dark vergence, an indicator of the ability to keep the eyes focused on the display.
  
  
  RESULTS
  Diagnostic accuracy was reduced after a day of clinical reading (P = .0246), but search time was not affected (P > .05). After a day of reading, dark vergence was significantly larger and more variable (P = .0098), reflecting higher levels of visual strain, and subjective ratings of fatigue were also higher.
  
  
  CONCLUSIONS
  After their usual workday, radiologists experience increased fatigue and decreased diagnostic accuracy for detecting pulmonary nodules on CT. Effects of fatigue may be mitigated by active interaction with the display.
authors.affiliation: Department of Radiology, University of Arizona, Tucson, AZ 85724, USA. krupinski@radiology.arizona.edu
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Krupinski
authors.forename: Kevin S
authors.initials: KS
authors.lastname: Berbaum
authors.forename: Robert T
authors.initials: RT
authors.lastname: Caldwell
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Schartz
authors.forename: Mark T
authors.initials: MT
authors.lastname: Madsen
authors.forename: David J
authors.initials: DJ
authors.lastname: Kramer
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D019540:Area Under Curve; D001130:Arizona; D002983:Clinical Competence; D005221:Fatigue; D006801:Humans; D007396:Internship and Residency; D007484:Iowa; D008297:Male; D008505:Medical Staff, Hospital / Q000458:organization & administration*; D008875:Middle Aged; D015588:Observer Variation; D012372:ROC Curve; D011857:Radiographic Image Interpretation, Computer-Assisted; D011871:Radiology / Q000193:education; D018570:Risk Assessment; D003074:Solitary Pulmonary Nodule / Q000175:diagnosis / Q000000981:diagnostic imaging*; D018709:Statistics, Nonparametric; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods / Q000706:statistics & numerical data; D014940:Work Schedule Tolerance; D016526:Workload