ORIGINAL ARTICLE Comparison of the diagnostic performance of CT colonography interpreted by radiologists and radiographers

Objective To compare computed tomographic colonography (CTC) performance of four trained radiographers with the CTC performance of two experienced radiologists. Methods Four radiographers and two radiologists interpreted 87 cases with 40 polyps ≥6 mm. Sensitivity, specificity, and positive predictive value (PPV) were assessed on a per-patient basis. On a per-polyp basis, sensitivitywas calculated according to the respective size categories (polyps ≥6 mm as well as polyps ≥10 mm). Results Overall per-patient sensitivity for polyps ≥6 mm was 76.2 % (95 % CI 61.4–91.0) and 76.2 % (95 % CI 61.7–90.6), for the radiographers and radiologists, respec-tively. Overall per-patient specificity for polyps ≥6 mm were 81.4 % (95 % CI 73.7–89.2) and 81.1 % (95 % CI 73.8– 88.3) for the radiographers and the radiologists, respectively. For the radiographers, overall per-polyp sensitivity was 60.3 % (95 % CI 50.3–70.3) and 60.7 % (95 % CI 42.2– 79.2) for polyps ≥6 mm and ≥10 mm, respectively. For the radiologists, overall per polyp sensitivity was 59.2 % (95%CI 46.4–72.0) and 69.0 % (95%CI 48.1–89.6) for polyps ≥6mm and ≥10 mm, respectively. Conclusion Radiographers with training in CTcolonographic evaluation achieved sensitivity and specificity in polyp detection comparable with that of experienced radiologists. Main messages • The diagnostic accuracy of trained radiographers was comparable to that of experienced radiologists. • The use of radiographers in reading CTC examinations is acceptable, however radiologists would still be necessary for the evaluation of extracolonic findings. • Skilled non-radiologists may play a vital role as a second reader of intraluminal findings or by performing quality control of examinations before patient dismissal