Linked Life Data

19926913

Source:http://linkedlifedata.com/resource/pubmed/id/19926913

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
24
pubmed:dateCreated
2009-12-2
pubmed:abstractText
Methods of measuring uncertainties in rigid body image registration of fan beam computed tomography (FBCT) to cone beam CT (CBCT) have been developed for automatic image registration algorithms in a commercial image guidance system (Synergy, Elekta, UK). The relationships between image registration uncertainty and both imaging dose and image resolution have been investigated with an anthropomorphic skull phantom and further measurements performed with patient images of the head. A new metric of target registration error is proposed. The metric calculates the mean distance traversed by a set of equi-spaced points on the surface of a 5 cm sphere, centred at the isocentre when transformed by the residual error of registration. Studies aimed at giving practical guidance on the use of the Synergy automated image registration, including choice of algorithm and use of the Clipbox are reported. The chamfer-matching algorithm was found to be highly robust to the increased noise induced by low-dose acquisitions. This would allow the imaging dose to be reduced from the current clinical norm of 2 mGy to 0.2 mGy without a clinically significant loss of accuracy. A study of the effect of FBCT slice thickness/spacing and CBCT voxel size showed that 2.5 mm and 1 mm, respectively, gave acceptable image registration performance. Registration failures were highly infrequent if the misalignment was typical of normal clinical set-up errors and these were easily identified. The standard deviation of translational registration errors, measured with patient images, was 0.5 mm on the surface of a 5 cm sphere centred on the treatment centre. The chamfer algorithm is suitable for routine clinical use with minimal need for close inspection of image misalignment.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1361-6560
pubmed:author
pubmed:issnType
Electronic
pubmed:day
21
pubmed:volume
54
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7263-83
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Investigation of uncertainties in image registration of cone beam CT to CT on an image-guided radiotherapy system.
pubmed:affiliation
Medical Physics and Engineering, St James's Hospital, Leeds Teaching Hospitals Trust, Leeds, LS9 7TF, UK. jonathan.sykes@leedsth.nhs.uk
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't