Application of subsecond rotation scan to helical CT for lung cancer screening.

Purpose: To clarify whether the benefit of a reduced effective scan width obtained using a smaller pitch outweighs the disadvantage of increased noise in the application of a subsecond helical CT to mass screenings for lung cancer.

Materials And Methods: Twenty-two helical CT scans of the lung were obtained in 11 healthy subjects using the following parameters: 1) scan 1 was performed at 120 kVp, 50 mA, 10-mm collimation, 1-second/rotation, helical pitch of 2.0; and 2) scan 2 was performed at 120 kVp, 50 mA, 10-mm collimation, 0.

Lung: feasibility of a method for changing tube current during low-dose helical CT.

A method for changing the tube current during helical scanning was applied to low-dose computed tomography (CT) in the lung. The changing method resulted in significant equalization of image noise in various lung sections compared with that at scanning with constant tube current. Detectability of nodules was equivalent between 60 mA and the changing method, whereas degradation occurred at 20 mA.