Computer aided diagnosis system with functions to assist comparative reading for lung cancer based on helical CT image

We have reported that a prototype computer-aided diagnosis (CAD) system to automatically detect suspicious regions from chest CT images had been presented by our group, and the CT screening system used was a TCT-900 super helix of the Toshiba Corporation. In this paper, we present a new and automatic method for an early diagnosis of lung cancer based on a CAD system in which all the CT images are read. Furthermore, the CAD system is equipped with functions to automatically detect suspicious regions from chest CT images, and to assist the comparative reading in retrospect. The key processes of the CAD system are a slice matching algorithm for comparison of each slice image of the present and past CT scans, and an interface to display some features of the suspicious regions. The experimental results indicate that our CAD system can work effectively.