| 摘要 |
The analysis involves a check on the apparatus setup and a check on the positioning of the patient. To check the apparatus setup a reference radiation field image is compared with a sample radiation field image to determine a difference image. At least the sample image is filtered to remove low frequency variations. A region of interest in the reference and sample images is selected and correlated with each other to determine relative displacements of the reference and sample image. The patient positioning is checked by determining relative displacements between reference image and sample image. The invention can be used for positioning of patient for radiation treatment of cancer to determine if radiation beam is correctly set up and if patient is positioned correctly, analysis of portal image is derived during first treatment session or using digitally reconstructed radiograph. |
