| Calibration and evaluation of a 252Cf-based neutron activation analysis instrument for the determination of nitrogen in vivo. | |
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MedLine Citation:
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PMID: 2813511 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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A novel clinical instrument for multi-element in vivo neutron activation analysis has been recently constructed in Swansea. The instrument is intended primarily for prompt gamma measurement of total and partial body calcium, total body nitrogen and partial body cadmium. For the measurement of nitrogen the subject is scanned both prone and supine across a vertical collimated neutron beam from a 4 GBq 252Cf source. Two shielded Nal(TI) detectors, each of volume 2760 cm3, are placed above the subject on the opposite side to that irradiated. The prompt gamma ray spectrum contains prominent peaks from hydrogen, nitrogen, chlorine and carbon. The optimisation, calibration and evaluation of the instrument for the measurement of nitrogen, by the reaction 14N(n, gamma)15N, is described. The calibration corrects the ratio of nitrogen-to-hydrogen counts measured from the subject for background gamma rays and the effects of body habitus. Body hydrogen is use as as internal standard. Repeated measurements of a homogeneous anthropomorphic phantom indicate that the ratio of nitrogen-to-hydrogen counts may be determined by a coefficient of variation of 1.6% for a neutron dose equivalent incident on the phantom of 0.45 mSv (QF = 10). The accuracy of the calibration was assessed by measuring three anthropomorphic phantoms (weight range: 41.4-110 kg) containing simulated skeletons and the major organs of the body. For these phantoms the mean discrepancy of the measured to the known nitrogen content was +4.9%. The simultaneous measurement of chlorine and carbon is discussed. |
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Authors:
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S J Ryde; W D Morgan; C J Evans; A Sivyer; J Dutton |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Physics in medicine and biology Volume: 34 ISSN: 0031-9155 ISO Abbreviation: Phys Med Biol Publication Date: 1989 Oct |
Date Detail:
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Created Date: 1989-11-29 Completed Date: 1989-11-29 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 0401220 Medline TA: Phys Med Biol Country: ENGLAND |
Other Details:
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Languages: eng Pagination: 1429-41 Citation Subset: IM |
Affiliation:
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Swansea In Vivo Analysis Research Group, Department of Medical Physics and Clinical Engineering, Singleton Hospital, UK. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Activation Analysis Calibration Californium Carbon / analysis Chlorine / analysis Gamma Rays Humans Hydrogen / analysis Models, Structural Neutron Activation Analysis / instrumentation* Nitrogen / analysis* Reproducibility of Results |
| Chemical | |
Reg. No./Substance:
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1333-74-0/Hydrogen; 7440-44-0/Carbon; 7440-71-3/Californium; 7727-37-9/Nitrogen; 7782-50-5/Chlorine |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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