Time-efficient CT colonography interpretation using an advanced image-gallery-based, computer-aided "first-reader" workflow for the detection of colorectal adenomas.
OBJECTIVE
To assess the performance of an advanced "first-reader" workflow for computer-aided detection (CAD) of colorectal adenomas ≥ 6 mm at computed tomographic colonography (CTC) in a low-prevalence cohort.


METHODS
A total of 616 colonoscopy-validated CTC patient-datasets were retrospectively reviewed by a radiologist using a "first-reader" CAD workflow. CAD detections were presented as galleries of six automatically generated two-dimensional (2D) and three-dimensional (3D) images together with interactive 3D target views and 2D multiplanar views of the complete dataset. Each patient-dataset was interpreted by initially using CAD image-galleries followed by a fast 2D review to address unprompted colonic areas. Per-patient, per-polyp, and per-adenoma sensitivities were calculated for lesions ≥ 6 mm. Statistical testing employed Fisher's exact and McNemar tests.


RESULTS
In 91/616 patients, 131 polyps (92 adenomas, 39 non-adenomas) ≥ 6 mm and two cancers were identified by reference standard. Using the CAD gallery-based first-reader workflow, the radiologist detected all adenomas ≥ 10 mm (34/34) and cancers. Per-patient and polyp sensitivities for lesions ≥ 6 mm were 84.3 % (75/89), and 83.2 % (109/131), respectively, with 89.1 % (57/64) and 85.9 % (79/92) for adenomas. Overall specificity was 95.6 % (504/527). Mean interpretation time was 3.1 min per patient.


CONCLUSIONS
A CAD algorithm, applied in an image-gallery-based first-reader workflow, can substantially decrease reading times while enabling accurate detection of colorectal adenomas in a low-prevalence population.


CONCLUSIONS
Computer-aided detection (CAD) is increasingly used to help interpret CT colonography (CTC). An image-gallery first-reader CAD-workflow is feasible for detection of colorectal adenomas ≥ 6 mm. Image-gallery first-reader CAD yields per-patient sensitivity of 89.1 % and specificity of 95.6 %. The mean reading time for CTC was 3.1 min, making screening feasible. No large adenoma was missed by the radiologist who reviewed with CAD galleries.
Department of Radiology, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria. thomas.mang@meduniwien.ac.at
Thomas
T
Mang
Gerardo
G
Hermosillo
Matthias
M
Wolf
Luca
L
Bogoni
Marcos
M
Salganicoff
Vikas
V
Raykar
Helmut
H
Ringl
Michael
M
Weber
Christina
C
Mueller-Mang
Anno
A
Graser
D000236:Adenoma / Q000000981:diagnostic imaging*; D000465:Algorithms; D023881:Colonography, Computed Tomographic; D015179:Colorectal Neoplasms / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D057188:Workflow