A computer-aided design mammography screening system for detection and classification of microcalcifications

This paper presents a prototype of a computer-aided design (CAD) diagnostic system for mammography screening to automatically detect and classify micr ocalcifications (MCCs) in mammograms. It comprises four modules. The first module, called the Mammogram Preprocessing Module, inputs and digitizes mam mograms into 8-bit images of size 2048 x 2048, extracts the breast region f rom the background, enhances the extracted breast and stores the processed mammograms in a data base. Since only clustered MCCs are of interest in pro viding a sign of breast cancer, the second module, called the MCCs Finder M odule, finds and locates suspicious areas of clustered MCCs, called regions of interest (ROIs). The third module, called the MCCs Detection Module, is a real time computer automated MCCs detection system that takes as inputs the ROIs provided by the MCCs Finder Module. It uses two different window s izes to automatically extract the microcalcifications from the ROIs. It beg ins with a large window of size 64 x 64 to quickly screen mammograms to fin d large calcified areas, this is followed by a smaller window of size 8 x 8 to extract tiny, isolated microcalcifications. Finally, the fourth module, called the MCCs Classification Module, classifies the detected clustered m icrocalcifications into five categories according to BI-RADS (Breast Imagin g Reporting and Data System) format recommended by the American College of Radiology. One advantage of the designed system is that each module is a se parate component that can be individually upgraded to improve the whole sys tem. Despite that it is still is a prototype system a preliminary clinical evaluation at TaiChung Veterans General Hospital (TCVGH) has shown that the system is very flexible and can be integrated with the existing Picture Ar chiving and Communications System (PACS) currently implemented in the Depar tment of Radiology at TCVGH. (C) 2000 Elsevier Science Ireland Ltd. All rig hts reserved.