Patent Document ID: 4856528
Application ID: 07066554
Patent Status: 1

Claim One:
1. A computer-aided method for determining the volume of a tumor within a body organ from CT image data of that organ, comprising the steps of: (a) obtaining CT image data for each of a plurality of slices of predetermined thickness of the body organ, the image data including a plurality of pixels and a CT number corresponding to each pixel; (b) transferring the CT image data into a computer; (c) displaying from the data in the computer an image of one of the slices; (d) computer generating an approximate boundary of the organ and displaying the boundary superimposed on the image of the slice; (e) operator interacting with the computer to modify the boundary generated by the computer to more accurately describe the boundary of the organ; (f) identifying, by the computer, the particular pixels within the organ boundary and the CT number associated with each such pixel and generating therefrom a local histogram of the slice, the histogram including data indicative of the number of pixels within the boundary having a particular CT number; (g) from the predetermined thickness and number of pixels identified within the boundary, determining by the computer, the volume of organ within the slice; (h) repeating steps (c) through (g) for each slice to so as to determine a local histogram corresponding to each slice; (i) summing the local histograms corresponding to the various slices to obtain a global histogram indicative of the number of pixels within the orga boundaries of respective slices having each particular CT number; (j) determining from the global histogram a demarcation CT number that distinguishes between normal organ tissue and tumor; (k) determining from the volume computations for each of the slices, the total volume of the organ; and (l) computing from the global histogram and demarcation CT number, the volume of the tumor.