The invention provides a novel method of high-resolution quantifiable pulmonary regional ventilation imaging using a package of computer programs, including deformable image registration and local volume change calculation on 4-D or breath-hold CT images. High resolution 3D ventilation images have been generated using this technique with superior quality. The deformation matrices between different respiration phases are calculated using deformable image registration and applied to calculate local volume change ΔV between respiration phases. The invention provides less image-noise and mismatch sensitivity than other techniques based on CT images, and is less expensive than nuclear medicine imaging. Implemented clinically, the method can derive a patient's pulmonary ventilation information from the same set of 4-D CT images, providing a cheaper but more accurate method to generate clinical lung ventilation image. Such information can be utilized in treatment planning sparing functional lung volumes without additional procedure and cost for lung functional imaging.