Apparatus for truncation correction of transmission CT and nuclear medical diagnostic apparatus using the same

摘要

SPECT data is collected to produce a SPECT image and transmission CT projection data is collected to produce a transmission CT image. The contours of the body of a subject under examination is extracted from the SPECT image. Using data representing the contours of the body, a portion of the transmission CT projection data is approximated by a curve. The sum of the curve-approximated transmission CT projection data and the center of gravity of the transmission CT image are computed. The truncated portion is estimated from the sum of the transmission CT projection data and the center of gravity of the transmission CT image and the transmission CT projection data is then corrected.The correction of the transmission CT projection data involves producing (extrapolation) anew a curve represented by a quadratic polynomial for that region (truncated region) of the transmission CT projection data which has been approximated tentatively by an ellipse in order to determine the sum and the center of gravity.