Acute appendicitis on abdominal MR images: training readers to improve diagnostic accuracy.
OBJECTIVE
To determine if training with direct feedback helps to improve the diagnostic performance of inexperienced readers in the detection of appendicitis on magnetic resonance (MR) images.


METHODS
The institutional review board approved this retrospective study and waived the requirement for informed consent. Nine radiologists and eight residents without experience in evaluating MR images for acute abdominal conditions evaluated a training set of images from 100 MR imaging examinations of patients suspected of having appendicitis and received direct feedback after each evaluation. An expert panel made a diagnosis of appendicitis in 45 patients and an alternative diagnosis in 55 patients on the basis of histopathologic examination and follow-up. Readers recorded two diagnoses: the first after viewing images from conventional MR sequences (half-Fourier rapid acquisition with relaxation enhancement and true fast imaging with steady-state precession) and the second after viewing diffusion-weighted (DW) MR images. Reader sensitivity and specificity were calculated per set of 25 cases.


RESULTS
The average reader sensitivity for detecting appendicitis improved significantly after training (0.82 vs 0.92, P = .003); the average specificity improved nonsignificantly (0.82 vs 0.88, P = .10). Sensitivity for radiologists increased from 0.81 in the first set of 25 cases to 0.91 in the last set, and specificity improved from 0.82 to 0.85. For residents, sensitivity increased from 0.82 to 0.94, and specificity increased from 0.82 to 0.91. Sensitivity improved from 0.80 to 0.87 (P < .001) in all readings combined when DW images were read in addition to conventional MR images.


CONCLUSIONS
Diagnostic accuracy of inexperienced readers in the evaluation of abdominal MR images for acute appendicitis improved after training with direct feedback, and the addition of DW images improved reader sensitivity.
Department of Radiology, Surgery, University of Amsterdam, Amsterdam, the Netherlands. m.m.leeuwenburgh@amc.uva.nl
Marjolein M N
MM
Leeuwenburgh
Bart M
BM
Wiarda
Shandra
S
Bipat
C Yung
CY
Nio
Thomas L
TL
Bollen
J Joost
JJ
Kardux
Sebastiaan
S
Jensch
Patrick M M
PM
Bossuyt
Marja A
MA
Boermeester
Jaap
J
Stoker
D000293:Adolescent; D000328:Adult; D000368:Aged; D001064:Appendicitis / Q000175:diagnosis*; D002648:Child; D002983:Clinical Competence; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
D003287:Contrast Media