Abstract: In this study an approach to open architecture computer-aided diagnosis (CAD) is presented. The traditional goal of a CAD system, to assist the physicians in performing the diagnosis and treatment, has been extended. The platform also supports the system designer in developing a new CAD workflow by implementing general-purpose modules as well as problem-dependent procedures. A new CAD may require new procedures to be added, yet some of the already implemented functions can be employed. The CAD environment is subjected to the developmental process of three systems: the multiple sclerosis CAD, the lung nodule CAD and the pneumothorax CAD. Modules and procedures are briefly described and the CAD systems are evaluated. Results obtained during the CAD evaluation show prospective flexibility of the infrastructure. The trade-offs, well known to CAD designers, can easily be handled by the operators in a user-friendly manner by choosing various workflow paths.