Computer aided diagnosis (CAD) is a relatively new technology that uses computer algorithms to analyze radiographic images and to help detect diseases.
The CAD software process consists of the following three steps:
- Segmentation: The boundary of lesions is determined and the image separated into regions inside and outside of the lesion.
- Image Processing (IP): Computer algorithms are used to measure the pertinent features of the lesion.
- Decision-making: Artificial Intelligence (AI) techniques are employed to make decisions whether the object, with all its features, is suggestive enough to be brought to the attention of the radiologist.
Typically a CAD system consists of three main parts:
- Scanner: Scans and digitizes the image such as for a mammogram (not needed when there is a direct digital system with a DICOM interface).
- Software: Sophisticated computer programs to analyze and annotate the image and prompt the radiologist to review areas that may suggest a lesion.
- Viewer: A high-resolution monitor that displays mammogram images as well as the overlay information generated by the CAD software.
CAD results are typically exchanged as a DICOM Structured Report. There are several applications for CAD, each with their own Structured Report, among them Mammography, lung nodules, and others.