3D Interpolation Method for CT Images of the Lung

摘要

A 3-D image is reconstructed from numerous CT images of the lung. The procedure reconstructs a solid from multiple cross section images, which are collected during pulsation of the heart. Thus the motion of the heart is a special factor that must be taken into consideration during reconstruction. The lung as an elastic body is repeating transformation synchronized to the beating of the heart. There are discontinuities among neighboring CT images due to the beating of the heart, if no special techniques are used in taking CT images. The 3-D heart image is reconstructed from numerous CT images in which both the heart and the lung are taken. Although the outline shape of the reconstructed 3-D heart is quite unnatural, the envelope of the 3-D unnatural heart is fit to the shape of the standard heart. The envelopes of the lung in the CT images are calculated after the section images of the best fitting standard heart are located at the same positions of the CT images. Thus the CT images are geometrically transformed to the optimal CT images fitting best to the standard heart. As correct transformation of images is required, an Area oriented interpolation method, proposed by us and hereafter referred to as AOI, is used for interpolation of transformed images. An attempt to reconstruct a 3-D lung image without discontinuity by a series of such operation is shown.