The present invention discloses apparatus, method, and system for CT image processing; said apparatus comprises: an interface unit for obtaining CT images; a target region separation unit for separating said target region from the CT images by means of judging the CT values of voxel points in said CT images, wherein points with CT values greater than or equal to the threshold for target region separation constitute the target region, and said target region comprises at least one separate region; a false positive region removing unit for removing false positive regions from said target region and obtaining the accurate target region. The present invention can be used to quickly and conveniently determine the target region to be detected, measure the characteristic data of the target region, and display the physical and relative positions of the target region in a three-dimensional manner; with a lower threshold for target region separation, the present invention can reduce the omission rate of detection; in addition, on that base, the present invention can remove possible false positive regions, thereby describing the target region accurately and improve accuracy of target information.