Trauma in CT: The Role of Severe Injury on Satisfaction of Search Revised.
OBJECTIVE
The satisfaction-of-search (SOS) effect occurs when an abnormality on an image is missed because another is found. The aim of this experiment was to test whether severe distracting fractures control the magnitude of SOS on other fractures when both appear in a single CT image.


METHODS
The institutional review board approved this study. The experimental (SOS) condition included 35 cervical spine CT cases, all of which contained severe cervical spine injuries. For each of these cases, a similar case was found that had no injuries. Image modification software was developed to add simulated fractures to each pair of cases, with and without a major injury. Sixteen different minor fractures were added to 16 of the 35 pairs of images. The 35 cases without native injuries constituted a control (non-SOS) condition mixed in a random order. Twenty radiologists read 35 mixed cases in each of two sessions. False-positive evaluations were collected only for cases without simulated fractures.


RESULTS
An SOS effect on the detection of simulated fractures was not observed. There was a nonsignificant (P = .07) finding of poorer detection in the presence of cases with severe injuries. However, the magnitude of the effect was no greater than has been observed for less severe distracting injuries.


CONCLUSIONS
The outcome agrees with the results of two previous experiments that failed to yield an SOS effect associated with detecting severe injuries, suggesting that the severity of a distracting injury does not determine whether a second injury is discovered.
Department of Radiology, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa. Electronic address: kevin-schartz@uiowa.edu.
Kevin M
KM
Schartz
Department of Radiology, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa.
Mark T
MT
Madsen
Section of Neuroradiology, Brigham and Women's Hospital, Boston, Massachusetts.
John
J
Kim
Northwestern University, Evanston, Illinois.
Riko
R
Ohashi
Department of Radiology, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa.
Kenjirou
K
Ohashi
Department of Radiology, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa.
George Y
GY
El-Khoury
Department of Radiology, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa.
Robert T
RT
Caldwell
Department of Radiology, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa.
Edmund A
EA
Franken
Department of Radiology, University of Iowa Roy J. and Lucille A. Carver College of Medicine, Iowa City, Iowa.
Kevin S
KS
Berbaum
D000328:Adult; D000368:Aged; D002983:Clinical Competence / Q000706:statistics & numerical data; D003951:Diagnostic Errors / Q000517:prevention & control / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007484:Iowa / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009104:Multiple Trauma / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D015588:Observer Variation; D015995:Prevalence; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016103:Spinal Fractures / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D014057:Tomography, X-Ray Computed / Q000706:statistics & numerical data*; D015599:Trauma Severity Indices
Diagnostic radiology; images; interpretation; observer performance; quality assurance