Document Detail


Overranging at multisection CT: an underestimated source of excess radiation exposure.
MedLine Citation:
PMID:  20631368     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
To reconstruct the first and last sections of a helical computed tomographic (CT) scan, the scan length is automatically extended beyond the planned image boundaries, a phenomenon known as overranging. With common 16-section CT scanning protocols, the overrange length is between 3 and 6 cm. For scanners with 64 or more sections, this length will be much greater, since overranging increases as pitch or detector collimation increases. Manufacturers have equipped the latest generation of CT scanners (128 sections or more) with overrange dose-reducing innovations that reduce overranging by typically up to 50%, which in the best cases reduces overranging to that of the previous scanner models (64 sections). To reduce the impact of overranging on radiosensitive organs just outside the planned scan region, it is best to use an axial protocol rather than a helical protocol. If this is not an option, lowering the pitch or the detector collimation will significantly reduce overranging. Finally, CT examinations should be planned in such a way that radiosensitive organs are as far as possible from the imaged volume.
Authors:
Arnold Schilham; Aart J van der Molen; Mathias Prokop; Hugo W de Jong
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Radiographics : a review publication of the Radiological Society of North America, Inc     Volume:  30     ISSN:  1527-1323     ISO Abbreviation:  Radiographics     Publication Date:    2010 Jul-Aug
Date Detail:
Created Date:  2010-07-15     Completed Date:  2010-11-30     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8302501     Medline TA:  Radiographics     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1057-67     Citation Subset:  IM    
Affiliation:
Department of Radiology, University Medical Center Utrecht, Heidelberglaan 100, 3584 CX Utrecht, the Netherlands. a.schilham@umcutrecht.nl
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MeSH Terms
Descriptor/Qualifier:
Body Burden*
Environmental Exposure / prevention & control*
Humans
Radiation Dosage*
Radiation Protection / methods*
Tomography, X-Ray Computed / methods*

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


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