Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1992-1-30
pubmed:abstractText
Radio-opaque markers implanted inside or placed on the skin of patients can be used to detect set-up errors and patient motion. The effects of imaging geometry accuracy for standard radiotherapy equipment on the precision of calculating the positions of radio-opaque spherical markers using two orthogonal radiographic film projections is investigated. Inaccuracies in the imaging geometry are computed from the manually digitized positions of the marker images on each film pair. Actual marker locations are calculated with a precision limited only by the variance in manual digitization by incorporating those imaging geometry inaccuracies into their computation. Results of a phantom study using a grid of markers in a plastic block indicate that submillimeter precision can be obtained for the spatial coordinates of individual markers, and that the precision is not sensitive to the small inaccuracies in imaging geometry present within the mechanical tolerances of modern radiotherapy treatment machines and simulators.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:issn
0094-2405
pubmed:author
pubmed:issnType
Print
pubmed:volume
18
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1126-31
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:articleTitle
Improvement of precision in spatial localization of radio-opaque markers using the two-film technique.
pubmed:affiliation
Department of Radiation Oncology, University of Michigan, Ann Arbor 48109-0010.
pubmed:publicationType
Journal Article