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Optimization of Gamma-Ray Counting and Spectrometry in Biomedical Tracer Studies; Optimisation du Comptage et de la Spectrometrie des Rayons Gamma dans des Etudes Biomedicales Faites a l'Aide de Traceurs; Optimizatsiya gamma-scheta i spektrometrii gamma-luchej v biomeditsinskikh issledovaniyakh s pomoshch'yu indikatorov; Optimizacion del Recuento y de la Espectrometry Gamma en los Estudios Biomedicos con Indicadores

Conference:

Abstract

In biomedical tracer studies, especially in man and even more so in children and pregnant women, it is important to operate at the lowest possible level of administered radioisotope that is commensurate with the required precision and accuracy of the subsequent radioassay measurements. Similarly, with administered stable elements (as specified compounds) or enriched stable isotopes (again, in compound form), followed by radioactivation analysis of resulting samples, it is important from the toxicological standpoint to minimize the amounts of administered element. The problem of optimization of counting of one, two and three gamma-emitting radioisotopes, by Nal(Tl) scintillation counting, single-channel spectrometry and multichannel spectrometry, has been considered in some detail in these laboratories, with particular attention to single-, double-, or triple-tagging tracer studies with radioisotopes frequently used in biomedical studies: {sup 51}Cr, {sup 198}Au, {sup 75}Se, {sup 197}Hg, {sup 64}Cu, {sup 76}As, {sup 82}Br, {sup 59}Fe, {sup 60}Co, {sup 42}K, and {sup 24}Na. The same considerations apply to the widely-used thermal-neutron activation analysis determinations of the corresponding elements or enriched stable isotopes, so the results of these counting optimization calculations have a double usefulness. The calculations are based on a few reasonable assumptions made on practical biomedical considerations, namely: (1) small samples  More>>
Authors:
Guinn, V. P. [1] 
  1. General Dynamics Corporation, San Diego, CA (United States)
Publication Date:
Oct 15, 1965
Product Type:
Conference
Report Number:
IAEA-SM-61/40
Resource Relation:
Conference: Symposium on Radioisotope Sample Measurement Techniques in Medicine and Biology, Vienna (Austria), 24-28 May 1965; Other Information: 12 refs., 3 tabs.; Related Information: In: Radioisotope Sample Measurement Techniques in Medicine and Biology. Proceedings of the Symposium on Radioisotope Sample Measurement Techniques| 741 p.
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 61 RADIATION PROTECTION AND DOSIMETRY; ACCURACY; ACTIVATION ANALYSIS; ARSENIC 76; BETA PARTICLES; BROMINE 82; CHILDREN; CHROMIUM 51; COBALT 60; COPPER 64; GAMMA RADIATION; GOLD 198; IRON 59; MERCURY 197; POTASSIUM 42; RADIOASSAY; SCINTILLATION COUNTING; SELENIUM 75; SODIUM 24; SPECTROSCOPY; STABLE ISOTOPES; THERMAL NEUTRONS; WOMEN
OSTI ID:
22131276
Research Organizations:
International Atomic Energy Agency, Vienna (Austria)
Country of Origin:
IAEA
Language:
English
Other Identifying Numbers:
Other: ISSN 0074-1884; TRN: XA13M2464086400
Submitting Site:
INIS
Size:
page(s) 17-31
Announcement Date:
Sep 19, 2013

Conference:

Citation Formats

Guinn, V. P. Optimization of Gamma-Ray Counting and Spectrometry in Biomedical Tracer Studies; Optimisation du Comptage et de la Spectrometrie des Rayons Gamma dans des Etudes Biomedicales Faites a l'Aide de Traceurs; Optimizatsiya gamma-scheta i spektrometrii gamma-luchej v biomeditsinskikh issledovaniyakh s pomoshch'yu indikatorov; Optimizacion del Recuento y de la Espectrometry Gamma en los Estudios Biomedicos con Indicadores. IAEA: N. p., 1965. Web.
Guinn, V. P. Optimization of Gamma-Ray Counting and Spectrometry in Biomedical Tracer Studies; Optimisation du Comptage et de la Spectrometrie des Rayons Gamma dans des Etudes Biomedicales Faites a l'Aide de Traceurs; Optimizatsiya gamma-scheta i spektrometrii gamma-luchej v biomeditsinskikh issledovaniyakh s pomoshch'yu indikatorov; Optimizacion del Recuento y de la Espectrometry Gamma en los Estudios Biomedicos con Indicadores. IAEA.
Guinn, V. P. 1965. "Optimization of Gamma-Ray Counting and Spectrometry in Biomedical Tracer Studies; Optimisation du Comptage et de la Spectrometrie des Rayons Gamma dans des Etudes Biomedicales Faites a l'Aide de Traceurs; Optimizatsiya gamma-scheta i spektrometrii gamma-luchej v biomeditsinskikh issledovaniyakh s pomoshch'yu indikatorov; Optimizacion del Recuento y de la Espectrometry Gamma en los Estudios Biomedicos con Indicadores." IAEA.
@misc{etde_22131276,
title = {Optimization of Gamma-Ray Counting and Spectrometry in Biomedical Tracer Studies; Optimisation du Comptage et de la Spectrometrie des Rayons Gamma dans des Etudes Biomedicales Faites a l'Aide de Traceurs; Optimizatsiya gamma-scheta i spektrometrii gamma-luchej v biomeditsinskikh issledovaniyakh s pomoshch'yu indikatorov; Optimizacion del Recuento y de la Espectrometry Gamma en los Estudios Biomedicos con Indicadores}
author = {Guinn, V. P.}
abstractNote = {In biomedical tracer studies, especially in man and even more so in children and pregnant women, it is important to operate at the lowest possible level of administered radioisotope that is commensurate with the required precision and accuracy of the subsequent radioassay measurements. Similarly, with administered stable elements (as specified compounds) or enriched stable isotopes (again, in compound form), followed by radioactivation analysis of resulting samples, it is important from the toxicological standpoint to minimize the amounts of administered element. The problem of optimization of counting of one, two and three gamma-emitting radioisotopes, by Nal(Tl) scintillation counting, single-channel spectrometry and multichannel spectrometry, has been considered in some detail in these laboratories, with particular attention to single-, double-, or triple-tagging tracer studies with radioisotopes frequently used in biomedical studies: {sup 51}Cr, {sup 198}Au, {sup 75}Se, {sup 197}Hg, {sup 64}Cu, {sup 76}As, {sup 82}Br, {sup 59}Fe, {sup 60}Co, {sup 42}K, and {sup 24}Na. The same considerations apply to the widely-used thermal-neutron activation analysis determinations of the corresponding elements or enriched stable isotopes, so the results of these counting optimization calculations have a double usefulness. The calculations are based on a few reasonable assumptions made on practical biomedical considerations, namely: (1) small samples ({<=} 10 ml), (2) moderate counting periods (s 20 minutes), (3) modest allowable decay periods ({<=} 3 days) and (4) use of commercially available counting equipment and shielding. On this basis, the most sensitive methods of counting each of the aforementioned radioisotopes, and a number of pairs and trios of them, have been ascertained. The counting variables included in the considerations are: (1) type of Nal(Tl) crystal, i.e., solid or well-type, (2) size of Nal(Tl) crystal, up to a 5 in x 5 in size, (3) type of measuring equipment: simple scalar, single-channel pulse-height analyser, or multichannel pulse-height analyser. The minimum detectable sample specific activity has been computed for each optimum counting situation, as well as the levels needed for statistical accuracies (expressed as standard deviations) of {+-} 20%, {+-} 10%, {+-} 5%, and {+-} 2%. In a number of illustrative cases, the calculated limits have been compared with experimentally determined values. Special attention has been devoted to the best conditions for minimization of contributions from lead X-rays, backscattered gamma-rays, escape peaks, sample beta-particles, and Bremsstrahlung. (author) [French] Lorsqu'on fait des etudes biomedicales a l'aide de radioindi- cateurs, notamment chez l'homme et plus particulierement chez les enfants et les femmes enceintes, il importe de limiter autant que possible la quantite de radioisotopes administres au minimum necessaire pour assurer la precision et Texactitude des mesures ulterieures de la radioactivite des specimens biologiques. De meme, il importe, du point de vue toxicologique, de reduire au minimum la quantite d'elements stables (sous forme de composes specifies) ou de radioisotopes stables enrichis (egalement sous forme de composes) administres en vue de faire l'analyse par radioactivation des echantillons ulterieurement preleves. Les auteurs ont etudie de maniere assez approfondie, en laboratoire, le probleme de l'optimisation du comptage des radioisotopes emettant un, deux et trois rayons gamma, au moyen de scintillateurs a Nal(Tl), de spectrometres a un canal et de spectrometres multicanaux, et on s'est attache plus particulierement aux etudes avec marquage au moyen de un, deux ou trois traceurs en utilisant les radioisotopes d'usage frequent dans les etudes biomedicales: {sup 51}Cr, {sup 198}Au, {sup 75}Se, {sup 197}Hg, {sup 64}Cu, {sup 76}As, {sup 82}Br, {sup 59}Fe, {sup 60}Co, {sup 42}K, et {sup 24}Na. Les memes considerations valent pour la methode bien connue d'analyse par activation avec neutrons thermiques des elements ou des radioisotopes stables enrichis correspondants, de sorte que les resultats de ces calculs d'optimisation du comptage presentent une double utilite. Les calculs sont faits sur la base de quelques hypotheses raisonnables elles-memes fondees sur des constatations biomedicales pratiques: 1. emploi d'echantillons de dimensions reduites ( Less-Than-Or-Equal-To 10 ml), 2. duree moyenne des temps de comptage ( Less-Than-Or-Equal-To 20 min), 3. emploi de radioisotopes dont la periode de desintegration est assez breve ( Less-Than-Or-Equal-To 3) et 4. utilisation d'ensembles de comptage et de blindage en vente dans le commerce. Sur ces bases, on a determine les methodes de comptage les plus sensibles pour chacun des radioisotopes ci-dessus et pour des groupes de deux ou trois d'entre eux. Pour le comptage,. les variables sont les suivantes: 1. type du cristal de Nal(Tl), c'est-a-dire cristal normal ou cristal a puits, 2. dimensions du cristal de Nal(Tl), qui peuvent atteindre 13 x 13 cm, 3. type des appareils de mesure: echelle de comptage simple, analyseur d'amplitude a un seul canal ou a plusieurs canaux. On a calcule l'activife specifique minimale decelable des echantillons pour chaque situation optimale ainsi que les quantites necessaires pour atteindre le degre d'exactitude qu'exigent les statistiques: ecarts types de {+-} 20%, {+-} 10%, {+-} 5% et {+-} 2%. L'auteur compare dans plusieurs exemples les valeurs limites theoriques aux valeurs determinees experimentalement. Une attention particuliere a ete accordee aux meilleures conditions permettant de reduire au minimum la radioactivite des rayons X emis par le plomb, des rayons gamma retrodiffuses, des pics de fuite, des particules beta emises par les echantillons et du rayonnement de freinage. (author) [Spanish] En los estudios biomedicos con indicadores, especialmente cuando se efectuan en el hombre y, sobre todo, en el nino y en la mujer embarazada, es importante administrar la menor cantidad de radioisotopos compatible con una medicion suficientemente precisa de la radiactividad. Lo mismo sucede, por razones toxicologicas, cuando se administran elementos estables (en torma de compuestos) o isotopos estables enriquecidos (tambien en forma de compuestos) y se analizan por radiactivacion las muestras correspondientes. El autor ha estudiado con cierto detalle el problema de la optimizacion del recuento de uno, dos y tres radioisotopos emisores gamma por centelleo con Nal(Tl) y espectrometria mono y multicanal, prestando especial atencion a los estudios efectuados por marcacion simple, doble o triple con los radioisotopos mas frecuentemente usados en los estudios biomedicos: {sup 51}Cr, {sup 198}Au, {sup 75}Se, {sup 197}Hg, {sup 64}Cu, {sup 76}As, {sup 82}Br, {sup 59}Fe, {sup 60}Co, {sup 42}K, y {sup 24}Na. Como las mismas consideraciones son aplicables al analisis corriente por activacion con neutrones termicos de los elementos correspondientes o de los isatopos estables enriquecidos, los resultados de los calculos de la optimizacion del recuento tienen una utilidad doble. Esos calculos parten de unas pocas suposiciones razonables basadas en consideraciones biomedicas practicas: a) muestras pequenas ( Less-Than-Or-Equal-To 10 cm{sup 3}) ; b) tiempos de recuento de mediana duracion ( Less-Than-Or-Equal-To 10 minutos) ; c) cortos perfodos de espera antes de la medicion ( Less-Than-Or-Equal-To 3 dias) y d) empleo de equipo de recuento y blindaje de tipo comercial. Partiendo de esta base se ha determinado cuales son los metodos mas sensibles de recuento para los mencionados radioisotopos y para algunas combinaciones de dos o tres de ellos. El recuento se ha estudiado en funcion de las siguientes variables: a) tipo del cristal de Nal(Tl), macizo o de cavidad; b) tamafio del cristal de Nal(Tl), hasta 5 x 5 pulg; c) equipo de medicion: escalfmetro simple, analizador de amplitudes de impulso monocanal o multicanal. Para cada circunstancia Sptima de recuento se ha calculado la actividad especifica minima detectable de la muestra, asi como los niveles requeridos para las precisiones estadfsticas (expresadas como desviaciones tipo) de {+-} 20%, {+-} 10%, {+-} 5% y {+-}2% En varios casos se han comparado los limites calculados con valores experimentales. Se ha prestado especial atencion a las mejores condiciones para reducir al mfnimo las contribuciones de los rayos X generados en el plomo, de los rayos gamma retrodispersos, de los maximos de escape, de las particulas beta de las muestras y de las radiaciones de frenado. (author) [Russian] V biomedicinskih issledovanijah s pomoshh'ju indikatorov, osobenno ljudej i, tem bolee, detej i beremennyh zhenshhin, vazhno rabotat' pri naimenee nizkom urovne vvodimyh radioizotopov, naskol'ko jeto sovmestimo s trebuemoj tochnost'ju i pravil'nost'ju posledujushhih izmerenij radioaktivnosti. Analo- gichnym obrazom, v sluchae vvedenija v organizm stabil'nyh jelementov (v vide opredelennyh soedinenij) ili obogashhennyh stabil'nyh izotopov (opjat'-taki v vide soedinenij) dlja dal'- nejshego radioaktivacionnogo analiza poluchennyh prob, s tochki zrenija toksikologii vazhno sokrashhat' do minimuma kolichestvo vvodimogo jelementa. V laboratorijah byla tshhatel'no izuchena problema optimizacii otschityvanija odnogo, dvuh n treh gamma-izluchajushhih radioizotopov pri pomoshhi scintilljacionnyh schetchikov s kristallom NaJ(Tl), odnokanal'noj i mnogokanal'noj spektrometrii, prichem osoboe vni- manie udeljalos' issledovanijam pri pomoshhi mechenija odnim, dvumja ili tremja indikatorami, naibolee chasto ispol'zuemymi v bnomedicinskih issledovanijah, a imenno: hrom-51, zoloto-198, selen-75, rtut'-197, med'-64, mysh'jak-76, brom-82, zhelezo-59, kobal't-60, kal'cij-42 i natrij-24. Odinakovye soobrazhenija otnosjatsja k opredeleniju pri pomoshhi shiroko ispol'zuemogo aktivacionnogo analiza teplovymi nejtronami sootvetstvujushhih jelementov ili obogashhennyh stabil'nyh izotopov, tak chto rezul'taty jetih raschetov opti- mizacii otschityvanija imejut dvojnuju pol'zu. V osnovu raschetov byli polozheny prostye gipotezy, osnovannye prakticheskih bio- medicinskih soobrazhenijah: 1) malyj razmer prob (ne bolee 10 ml); 2) ogranichennoe vremja' otschityvanija (ne bolee 20 min); 3) nebol'shie dopustimye periody raspada (ne bolee treh sutok) i 4) ispol'zovanie imejushhegosja v prodazhe oborudovanija dlja otscheta i zashhity. Na jetoj osnove byli opredeleny naibolee chuvstvitel'nye metody otscheta dlja kazhdogo iz vysheupomjanutyh radioizotopov, a takzhe dlja ih par i troek. Uchityvalis' sledujushhie peremennye velichiny otscheta: 1) tip kristalla NaJ (T1), a imenno cel'nyj ili s kanalom, 2) razmer kristalla NaJ (T1)-do5h 5 djujmov i 3) tip izmeritel'nyh priborov: prostaja pereschetnaja shema, odnokanal'nyj i mnogokanal'nyj analizator amplitudy impul'sov. Dlja kazhdogo optimal'nogo uslovija otscheta podschitany minimal'naja ulovimaja udel'naja aktivnost' proby, a takzhe urovni ee, neobhodimye dlja sobljudenija statisticheskoj pra- vil'nosti (vyrazhennoj v vide standartnyh otklonenij) v predelah {+-}20, {+-}10, {+-}5 i {+-}2% . Dlja celogo rjada pokazatel'nyh sluchaev raschetnye predely byli sopostavleny s jeksperi- mental'nymi. Osoboe vnimanie udeljalos' nailuchshim uslovijam ponizhenija do minimuma doli izluchaemyh svincom rentgenovskih luchej, obratnogo rassejanija gamma-luchej, pikov utechki, chisla beta-chastic v probe i tormoznogo izluchenija. (author)}
place = {IAEA}
year = {1965}
month = {Oct}
}