Helical CT, and the newest technological development, multislice CT (multidetector CT: MDCT), have revolutionized the diagnostic approach to diseases of the chest including lung cancer. There are several factors that contribute to the important role of multislice CT scanning of the chest: (1) data acquisition is so rapid that the scanning of the entire lung can be performed during a single breath-hold period; (2) continuous acquisition of thin slices allows the improvement of the image quality of multiplanar reconstruction of thoracic abnormalities; (3) MDCT may help reduce the radiation dose, so that, compared to conventional or single-slice helical CT, the radiation dose is lowered with comparable image quality. The advantages of MDCT include both improved nodule detection and nodule characterization on lung cancer screening programs, because the entire lung can be scanned with thin slice in a single breath-hold without an intersection gap. In the evaluation of lung cancer, MDCT will allow improved detection of pleural dissemination and hilar lymph node adenopathy because of the continuous and narrow scan collimation.