Document Detail


A total body nitrogen facility for paediatric use.
MedLine Citation:
PMID:  1745663     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The design, calibration and evaluation of a facility for in vivo prompt gamma neutron capture analysis of total body nitrogen in children is described. The patient is scanned in both supine and prone positions, across a vertically collimated beam from a 1 GBq 252Cf fission source. Two NaI(T1) detectors are placed on either side of the patient, perpendicular to both the neutron beam and the scanning direction. The effective dose equivalent delivered to a child during an 840 s scan is approximately 0.14 mSv (QF = 10). Correction factors for nitrogen background (width-dependent), hydrogen background (1-4% of hydrogen gamma ray peak) and the differential attenuation of nitrogen and hydrogen gamma rays (width-dependent) can be applied to the measured nitrogen-to-hydrogen gamma ray counts ratio. By using the mass of hydrogen (based on body mass and fat mass) as an internal standard, the nitrogen mass can then be determined. Measurements with a urea-containing box phantom show that the current precision (CV) of the net nitrogen counts and of the nitrogen-to-hydrogen counts ratio is +/- 2.0% and +/- 1.5%, respectively. Using small anthropomorphic and other phantoms, estimation of the mass of nitrogen has a precision of +/- 1.4 to 5.4% and an accuracy of 97.1 to 101.5%.
Authors:
L A Baur; B J Allen; A Rose; N Blagojevic; K J Gaskin
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Physics in medicine and biology     Volume:  36     ISSN:  0031-9155     ISO Abbreviation:  Phys Med Biol     Publication Date:  1991 Oct 
Date Detail:
Created Date:  1992-01-16     Completed Date:  1992-01-16     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0401220     Medline TA:  Phys Med Biol     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  1363-75     Citation Subset:  IM    
Affiliation:
James Fairfax Institute of Paediatric Clinical Nutrition, Children's Hospital, Camperdown, New South Wales, Australia.
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MeSH Terms
Descriptor/Qualifier:
Australia
Child
Facility Design and Construction*
Humans
Neutrons
Nitrogen / analysis*
Protein-Energy Malnutrition / prevention & control*
Chemical
Reg. No./Substance:
7727-37-9/Nitrogen

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


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