Effect of directed training on reader performance for CT colonography: multicenter study.

PURPOSE To define the interpretative performance of radiologists experienced in computed tomographic (CT) colonography and to compare it with that of novice observers who had undergone directed training, with colonoscopy as the reference standard. MATERIALS AND METHODS Physicians at each participating center received ethical committee approval and followed the committees' requests regarding informed consent. Nine experienced radiologists, nine trained radiologists, and 10 trained technologists from nine centers read 40 CT colonographic studies selected from a data set of 51 studies and modeled to simulate a population with positive fecal occult blood test results: Studies were obtained in eight patients with cancer, 12 patients with large polyp, four patients with medium polyp, and 27 patients without colonic lesions. Findings were verified with colonoscopy. An experienced radiologist used 50 endoscopically validated studies to train novice observers before they were allowed to participate. Observers used one software platform to read studies over 2 days. Responses were collated and compared with the known diagnostic category for each subject. The number of correctly classified subjects was determined for each observer, and differences between groups were examined with bootstrap analysis. RESULTS Overall, 28 observers read 1084 studies and detected 121 cancers, 134 large polyps, and 33 medium polyps; 448 healthy subjects were categorized correctly. Experienced radiologists detected 116 lesions; trained radiologists and technologists detected 85 and 87 lesions, respectively. Overall accuracy of experienced observers (74.2%) was significantly better than that of trained radiologists (66.6%) and technologists (63.2%). There was no significant difference (P=.33) between overall accuracy of trained radiologists and that of technologists; however, some trainees reached the mean performance achieved by experienced observers. CONCLUSION Experienced observers interpreted CT colonographic images significantly better than did novices trained with 50 studies. On average, no difference between trained radiologists and trained technologists was found; however, individual performance was variable and some trainees outperformed some experienced observers.

[1]  H. Forman,et al.  Self-referred whole-body imaging: where are we now? , 2004, Radiology.

[2]  J. Burdick,et al.  Computed tomographic colonography (virtual colonoscopy): a multicenter comparison with standard colonoscopy for detection of colorectal neoplasia. , 2004, JAMA.

[3]  P. Alderson,et al.  A balanced subspecialization strategy for radiology in the new millennium. , 2000, AJR. American journal of roentgenology.

[4]  I. Talbot,et al.  The prevalence of small, flat colorectal cancers in a western population , 2004, Colorectal disease : the official journal of the Association of Coloproctology of Great Britain and Ireland.

[5]  J. Saurin,et al.  [Computed tomographic virtual colonoscopy to screen for colorectal neoplasia in asymptomatic adults]. , 2004, Gastroenterologie clinique et biologique.

[6]  J. Olsen,et al.  Randomised study of screening for colorectal cancer with faecal-occult-blood test , 1996, The Lancet.

[7]  J. Yee,et al.  Computerized tomographic colonography: performance evaluation in a retrospective multicenter setting. , 2003, Gastroenterology.

[8]  C. Johnson,et al.  Prospective blinded evaluation of computed tomographic colonography for screen detection of colorectal polyps. , 2003, Gastroenterology.

[9]  F. Earnest,et al.  Understanding interpretive errors in radiologists learning computed tomography colonography. , 2004, Academic radiology.

[10]  K. Kopecky,et al.  An initial experience with screening for colon polyps using spiral CT with and without CT colography (virtual colonoscopy) , 1999, Gastrointestinal endoscopy.

[11]  D. Wolverton,et al.  Performance parameters for screening and diagnostic mammography: specialist and general radiologists. , 2002, Radiology.

[12]  I. Hassan.  Observer variation in the detection of colorectal neoplasia on double-contrast barium enema: implications for colorectal cancer screening and training. , 2005, Clinical radiology.

[13]  Stuart A. Taylor,et al.  CT colonography: effect of experience and training on reader performance , 2004, European Radiology.

[14]  A. Hara,et al.  Detection of flat lesions in the colon with CT colonography , 2002, Abdominal Imaging.

[15]  S. Moss,et al.  Randomised controlled trial of faecal-occult-blood screening for colorectal cancer , 1989, The Lancet.

[16]  S. Halligan,et al.  CT colonography practice in the UK: a national survey. , 2004, Clinical radiology.

[17]  T. Fujii,et al.  Flat and depressed colonic neoplasms: a prospective study of 1000 colonoscopies in the UK , 2000, The Lancet.

[18]  Stuart A. Taylor,et al.  CT colonography in the detection of colorectal polyps and cancer: systematic review, meta-analysis, and proposed minimum data set for study level reporting. , 2005, Radiology.

[19]  L. Brown,et al.  Cost-effectiveness of Barium Enemas Performed by Radiographers , 2002 .

[20]  S. Hughes,et al.  Double contrast barium enema sensitivity: a comparison of studies by radiographers and radiologists. , 2002, Clinical radiology.

[21]  T. Raffin,et al.  Self-referred whole-body CT imaging: current implications for health care consumers. , 2003, Radiology.

[22]  P. Lavin,et al.  CT colonography of colorectal polyps: a metaanalysis. , 2003, AJR. American journal of roentgenology.

[23]  L M Schuman,et al.  Reducing mortality from colorectal cancer by screening for fecal occult blood. Minnesota Colon Cancer Control Study. , 1993, The New England journal of medicine.

[24]  P. Pickhardt,et al.  Computed tomographic virtual colonoscopy to screen for colorectal neoplasia in asymptomatic adults. , 2003, The New England journal of medicine.