Document Detail


Assessment of geometrical accuracy of magnetic resonance images for radiation therapy of lung cancers.
MedLine Citation:
PMID:  14604425     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The purpose of this research was to investigate the geometrical accuracy of magnetic resonance (MR) images used in the radiation therapy treatment planning for lung cancer. In this study, the capability of MR imaging to acquire dynamic two-dimensional images was explored to access the motion of lung tumors. Due to a number of factors, including the use of a large field-of-view for the thorax, MR images are particularly subject to geometrical distortions caused by the inhomogeneity and gradient nonlinearity of the magnetic field. To quantify such distortions, we constructed a phantom, which approximated the dimensions of the upper thorax and included two air cavities. Evenly spaced vials containing contrast agent could be held in three directions with their cross-sections in the coronal, sagittal, and axial planes, respectively, within the air cavities. MR images of the phantom were acquired using fast spin echo (FSE) and fast gradient echo (fGRE) sequences. The positions of the vials according to their centers of mass were measured from the MR images and registered to the corresponding computed tomography images for comparison. Results showed the fGRE sequence exhibited no errors >2.0 mm in the sagittal and coronal planes, whereas the FSE sequence produced images with errors between 2.0 and 4.0 mm along the phantom's perimeter in the axial plane. On the basis of these results, the fGRE sequence was considered to be clinically acceptable in acquiring images in all sagittal and coronal planes tested. However, the spatial accuracy in periphery of the axial FSE images exceeded the acceptable criteria for the acquisition parameters used in this study.
Authors:
N Koch; H H Liu; L E Olsson; E F Jackson
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Journal of applied clinical medical physics / American College of Medical Physics     Volume:  4     ISSN:  1526-9914     ISO Abbreviation:  J Appl Clin Med Phys     Publication Date:  2003  
Date Detail:
Created Date:  2003-11-07     Completed Date:  2004-01-20     Revised Date:  2004-11-17    
Medline Journal Info:
Nlm Unique ID:  101089176     Medline TA:  J Appl Clin Med Phys     Country:  United States    
Other Details:
Languages:  eng     Pagination:  352-64     Citation Subset:  IM    
Copyright Information:
(c) 2003 American College of Medical Physics.
Affiliation:
Department of Radiation Physics, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston 77030, USA. nckoch@mdanderson.org
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MeSH Terms
Descriptor/Qualifier:
Computer Simulation
Humans
Image Interpretation, Computer-Assisted / methods,  standards
Lung Neoplasms / pathology,  radiotherapy*
Magnetic Resonance Imaging / standards*
Models, Theoretical
Phantoms, Imaging / standards
Quality Assurance, Health Care / methods
Radiotherapy Planning, Computer-Assisted / methods,  standards
Radiotherapy, Computer-Assisted / methods,  standards

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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