Computed tomographic colonography: assessment of radiologist performance with and without computer-aided detection.
OBJECTIVE
In isolation, computer-aided detection (CAD) for computed tomographic (CT) colonography is as effective as optical colonoscopy for detection of significant adenomas. However, the unavoidable interaction between CAD and the reader has not been addressed.


METHODS
Ten readers trained in CT but without special expertise in colonography interpreted CT colonography images of 107 patients (60 with 142 polyps), first without CAD and then with CAD after temporal separation of 2 months. Per-patient and per-polyp detection were determined by comparing responses with known patient status.


RESULTS
With CAD, 41 (68%; 95% confidence interval [CI], 55%-80%) of the 60 patients with polyps were identified more frequently by readers. Per-patient sensitivity increased significantly in 70% of readers, while specificity dropped significantly in only one. Polyp detection increased significantly with CAD; on average, 12 more polyps were detected by each reader (9.1%, 95% CI, 5.2%-12.8%). Small- (< or =5 mm) and medium-sized (6-9 mm) polyps were significantly more likely to be detected when prompted correctly by CAD. However, overall performance was relatively poor; even with CAD, on average readers detected only 10 polyps (51.0%) > or =10 mm and 24 (38.2%) > or =6 mm. Interpretation time was shortened significantly with CAD: by 1.9 minutes (95% CI, 1.4-2.4 minutes) for patients with polyps and by 2.9 minutes (95% CI, 2.5-3.3 minutes) for patients without. Overall, 9 readers (90%) benefited significantly from CAD, either by increased sensitivity and/or by reduced interpretation time.


CONCLUSIONS
CAD for CT colonography significantly increases per-patient and per-polyp detection and significantly reduces interpretation times but cannot substitute for adequate training.
Halligan
Steve
S
Department of Specialist Radiology, University College Hospital, London, England. s.halligan@ucl.ac.uk
Altman
Douglas G
DG
Mallett
Susan
S
Taylor
Stuart A
SA
Burling
David
D
Roddie
Mary
M
Honeyfield
Lesley
L
McQuillan
Justine
J
Amin
Hamdan
H
Dehmeshki
Jamshid
J
D000236:Adenoma / Q000000981:diagnostic imaging*; D003106:Colon / Q000000981:diagnostic imaging*; D003110:Colonic Neoplasms / Q000000981:diagnostic imaging*; D003111:Colonic Polyps / Q000000981:diagnostic imaging; D023881:Colonography, Computed Tomographic / Q000379:methods*; D003936:Diagnosis, Computer-Assisted / Q000379:methods; D006801:Humans; D011361:Professional Competence; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity