Patent ID: 6466639
Filing Date: 2002-10-15
Classification: A61B

Abstract:
A subject center position detection method comprising the steps of:acquiring a projection profile by imaging a subject from a direction orthogonal to a plane containing a body axis of the subject by an X-ray CT apparatus for performing a scan by an X-ray tube rotating around the subject; defining an X-ray detector channel index corresponding to a calculated centroid of said projection profile as a centroid channel index; examining a projection value in said projection profile toward a direction along a first direction of the subject from said centroid channel index; defining a channel index having a projection value no more than a predetermined projection value threshold Pth as a first threshold channel index; examining on the other hand a projection value in said projection profile toward a direction along a second direction of the subject opposite to said first direction from said centroid channel index; defining a channel index having a projection value no more than the predetermined projection value threshold Pth as a second threshold channel index; defining an intermediate value between said first and second threshold channel indices as a subject position channel index; and obtaining a subject center position from said subject position channel index.