Título: 3-D automatic anatomy-based image registration in portal imaging
Autores: Sirois, Luc M.
Fecha: 1999
Publicador: McGill University - MCGILL
Fuente:
Tipo: Electronic Thesis or Dissertation
Tema: Health Sciences, Radiology.
Physics, Radiation.
Biophysics, Medical.
Descripción: A three dimensional, automatic, anatomy-based system for portal verification has been developed based on an FFT implementation of Pearson's correlation coefficient (PCC). The PCC requires no anatomy or point-pair identification, is robust when encountering changes in scaling and shifts in image amplitudes and requires no priori knowledge of the anatomy, which makes it an ideal candidate for portal-to-DRR image registration. Features for matching are selected from orthogonal portal images and compared to the corresponding megavoltage DRR. The position of the highest correlation value is then converted into beam-to-patient geometry and compared with the actual patient setup. By continuously generating DRRs, the system is capable of verifying translation errors, in-plane rotation and out-of-plane rotation errors. The mean accuracy of translation and rotation registrations tests were 0.58 mm and 0.79° respectively for DRR-to-DRR matching, and 1.22 mm and 1.31° respectively for portal-to-DRR matching.
Idioma: en