IMAGE-PROCESSING FOR COMPUTER-AIDED DIAGNOSIS OF LUNG-CANCER BY CT (LSCT)

This paper reports a special-purpose CT for early detection of lung cancer and presents the basic idea. The parallel use of the following two systems is investigated as the diagnosis-support image display method needed in such a system, and a satisfactory result is obtained. (1) The maximum intensity projection (MIP) is applied as a means to realize the two-dimensional projection display from the three-dimensional information composed of 40 slices of lung tissue while retaining the information concerning the pathological shadows. When the simple MIP is applied, there is a large disturbance due to unnecessary organ signals. Consequently, a method is developed in which unnecessary information is deleted by thresholding; (2) The automatic recognition of candidates for the pathological shadows is applied to each slice. Only the CT image containing a shadow candidate is displayed on CRT, which helps to reduce greatly the number of cross sections to be displayed. In the automatic recognition of the pathological shadow, the quoit filter recently developed by the authors is employed.