Premium
Determination of rotations in three dimensions using two‐dimensional portal image registration
Author(s) -
Lujan Anthony E.,
Balter James M.,
Ten Haken Randall K.
Publication year - 1998
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.598253
Subject(s) - radiography , rotation (mathematics) , imaging phantom , computer vision , artificial intelligence , planar , orientation (vector space) , feature (linguistics) , computer science , image registration , medical imaging , plane (geometry) , computed radiography , medicine , mathematics , nuclear medicine , radiology , computer graphics (images) , geometry , image (mathematics) , image quality , linguistics , philosophy
The relative relationships among anatomic features visualized on planar radiographic images change due to rotations of the patient out of the imaging plane. These changes can be predicted a priori from a three‐dimensional radiographic model of the patient. In this study we assess the feasibility of using that information together with a planar image feature alignment tool to account for out‐of‐plane rotations in the evaluation of subsequent clinical patient images. A series of digitally reconstructed radiographs (DRRs) with known patient rotations was generated from a computed tomography scan of an anthropomorphic head phantom. Fixed anatomic features were extracted, as seen in the DRRs of rotated anatomy and entered into a database. Alignment of features from test radiographs with those from an entry in this database yielded an estimate of rotation out of plane (database entry that resulted in the best fit via planar transformation) along with the planar components of setup errors in the rotated plane. Tests using DRRs and films show that it is possible to select anatomic features in AP skull radiographs with position and orientation sensitive to out‐of‐plane rotation.