Computer-aided detection systems in CT Colonography - mitigating reviewers experiences in emerging radiology groups for cost-effective practices: a case study on the NCIA ACRIN 6664 datasets

F. Chandelier, L. Stein; ECR 2011 Book of Abstracts (B-121)
Purpose: The aim of the present study is to assess the performance of a new Computer-Aided Detection (CAD) system for lesions > 9 mm on tagged patient preparations, while preserving a cost-effective practice amongst inexperienced and experienced reviewers.

Methods and Materials: CT Colonography (CTC) is defined as a legitimate colorectal cancer screening method, as suggested by systematic meta-analysis concluding "there is convincing diagnostic evidence for the detection of lesions > 9 mm and strong diagnostic evidence for lesions 6-9 mm" [Digestion:80;2009]. Such patient friendly screening protocol increases the demand for CTC readings, shifting CTC practices to outside specialised academic centres. As more inexperienced readers are involved, proper training and tools should be provided to maintain quality standards defined as > 83% detection for lesions > 9 mm. The stand-alone performance of CADENS Imaging CAD Colon was investigated in an asymptomatic population representative of the variability in existing clinical settings, compared to optically reported lesions > 9 mm. The ACRIN6664 database provided by the USA National Cancer Institute represented the population of interest. This CAD will be involved in an academic protocol (McGill University, Quebec, Canada) to prospectively investigate its overall contribution to both experienced and inexperienced readers.

Results: The CAD featured a detection rate similar to experienced radiologists, with a per-lesion sensitivity of 82% and a CAD average false-positive of 5/patient, delivering the cost-effective 83% per-patient detection-threshold for lesions > 9 mm.

Conclusion: CAD for CTC can significantly contribute in the emergence of cost effective CTC practices depicting variable reviewers' expertise. It is a unique opportunity to answer the immediate and ever growing demand for CTC readings.