Two active topics in radiation therapy treatment verification, portal image segmentation and correlation, are addressed, and a robust algorithm for automatic segmentation of portal images and portal image registration with respect to a reference image is developed. Morphological techniques have been intensively applied in all stages of the segmentation part of this algorithm, from edge detection to feature extraction. An important issue, edge enhancement, is discussed particularly in detail. The performance of the morphological edge detection technique on portal images is compared with that of local gradient operators and optimal edge detectors, while the advantage of the morphological edge detection and segmentation techniques is justified. The treatment field mask is proposed as the landmark for portal-simulator image correlation achieved by matching inertia moments of landmarks. The effect of two different landmarks, the treatment field mask and the treatment field contour, is examined with this correlation method, and the superiority of using the treatment field mask is shown.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.69717 |
| Date | January 1993 |
| Creators | Wang, Hui |
| Contributors | Fallone, B. Gino (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Physics.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001391963, proquestno: AAIMM91815, Theses scanned by UMI/ProQuest. |
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