In this paper, we present an enhancement of bit-planes based method used in the phase of extracting lung region from 3D chest images which is considered a key challenge in computer aided diagnosis systems designed for early detection of lung cancer. The chest 3D-CT images are used without any preprocessing in order to keep the entire information intact within the raw data. The results show that bit-plane 1 and bit-plane 2 are both needed to extract the exact information from the 3D-CT images. Our method is implemented and tested on a database of normal and abnormal cases composed of more than 1000 CT intensity images, and has successfully extracted lung regions in almost all of the cases.

3D-CT-Chest images, Lung Cancer, bit-plane slicing, lung region extraction.