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Theory of Radioisotope Scanning; Theorie de l'Exploration au Moyen d'un Radioisotope; Matematicheskaya osnova radioizotopnogo skennirovaniya; Teoria de la Exploracion Radioisotopica

Conference:

Abstract

All scanning techniques, whether utilizing focusing collimators, positron detectors or the newer camera techniques, have certain basic problems. The success of these techniques depends in large measure upon the correct choice of various parameters of the collimating system, of which the most important is the resolution. In this paper the relationship of optimum resolution to radioisotope content and distribution are discussed. Radioisotope scanning may be considered as a process of information extraction and presentation. The primary information lies in the original radioisotope distribution. The collimator and detecting system provide the information transfer mechanism and the final scan presents the resultant information. As with all such techniques, only a small fraction of the information is retained in the final scan. It can be shown that for focusing collimator and scintillation camera systems, the number of counts per resolution area varies as the fourth power of the resolution distance. For certain radioisotope distributions it is possible to derive analytically an optimum value of resolution distance. However, for most systems the optimum resolution must be determined by trial and error. The problems here are similar to those of pattern recognition in other fields. A computer programme has been prepared to aid in determining  More>>
Authors:
Brownell, G. L. [1] 
  1. Massachusetts General Hospital, Boston, MA (United States)
Publication Date:
Oct 15, 1964
Product Type:
Conference
Report Number:
IAEA-SM-51/58
Resource Relation:
Conference: Symposium on medical radioisotope scanning, Athens (Greece), 20-24 Apr 1964; Other Information: 17 refs., 17 figs., 5 tabs.; Related Information: In: Medical Radioisotope Scanning. Vol. I. Proceedings of the Symposium on Medical Radioisotope Scanning| 574 p.
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 62 RADIOLOGY AND NUCLEAR MEDICINE; COLLIMATORS; DESIGN; ERRORS; GAMMA CAMERAS; NUCLEAR MEDICINE; PATTERN RECOGNITION; POSITRONS; RADIOISOTOPE SCANNING; RADIOISOTOPES; READOUT SYSTEMS; RESOLUTION
OSTI ID:
22127626
Research Organizations:
International Atomic Energy Agency, Vienna (Austria)
Country of Origin:
IAEA
Language:
English
Contract Number:
Contract AT-(30-l) 1242; AM 05423
Other Identifying Numbers:
Other: ISSN 0074-1884; TRN: XA13M3039082705
Submitting Site:
INIS
Size:
page(s) 3-33
Announcement Date:
Sep 12, 2013

Conference:

Citation Formats

Brownell, G. L. Theory of Radioisotope Scanning; Theorie de l'Exploration au Moyen d'un Radioisotope; Matematicheskaya osnova radioizotopnogo skennirovaniya; Teoria de la Exploracion Radioisotopica. IAEA: N. p., 1964. Web.
Brownell, G. L. Theory of Radioisotope Scanning; Theorie de l'Exploration au Moyen d'un Radioisotope; Matematicheskaya osnova radioizotopnogo skennirovaniya; Teoria de la Exploracion Radioisotopica. IAEA.
Brownell, G. L. 1964. "Theory of Radioisotope Scanning; Theorie de l'Exploration au Moyen d'un Radioisotope; Matematicheskaya osnova radioizotopnogo skennirovaniya; Teoria de la Exploracion Radioisotopica." IAEA.
@misc{etde_22127626,
title = {Theory of Radioisotope Scanning; Theorie de l'Exploration au Moyen d'un Radioisotope; Matematicheskaya osnova radioizotopnogo skennirovaniya; Teoria de la Exploracion Radioisotopica}
author = {Brownell, G. L.}
abstractNote = {All scanning techniques, whether utilizing focusing collimators, positron detectors or the newer camera techniques, have certain basic problems. The success of these techniques depends in large measure upon the correct choice of various parameters of the collimating system, of which the most important is the resolution. In this paper the relationship of optimum resolution to radioisotope content and distribution are discussed. Radioisotope scanning may be considered as a process of information extraction and presentation. The primary information lies in the original radioisotope distribution. The collimator and detecting system provide the information transfer mechanism and the final scan presents the resultant information. As with all such techniques, only a small fraction of the information is retained in the final scan. It can be shown that for focusing collimator and scintillation camera systems, the number of counts per resolution area varies as the fourth power of the resolution distance. For certain radioisotope distributions it is possible to derive analytically an optimum value of resolution distance. However, for most systems the optimum resolution must be determined by trial and error. The problems here are similar to those of pattern recognition in other fields. A computer programme has been prepared to aid in determining the optimum resolution for various types of patterns. This computer is unique in having intermediate disc storage and CRT read-out. The results have general applicability to the design of many scanning systems. (author) [French] Toutes les methodes d'exploration au moyen d'un radioisotope, celles qui font appel aux collimateurs a focalisation, aux detecteurs de positons ou les techniques plus recentes utilisant des cameras a scintillation, posent certains problemes fondamentaux. Le succes de ces techniques depend beaucoup du choix des differents parametres du dispositif de collimation, dont le plus important est la resolution. L'auteur etudie les relations qui existent entre la resolution optimum, d'une part, la concentration du radioisotope et sa repartition, d'autre part. L'exploration au moyen d'un radioisotope peut etre consideree comme un moyen d'extraire et de presenter des informations. Les informations primaires se trouvent dans la repartition initiale du radioisotope. Le collimateur et l e detecteur constituent le mecanisme de transfert de l'information et le scintigramme final presente les informations obtenues. Comme dans toutes les techniques de ce genre, le scintigramme final ne contient qu'une faible partie des informations. On peut montrer que, dans le cas d'ensembles comportant un collimateur a focalisation ou une camera a scintillation, le nombre de coups par surface de resolution varie comme la quatrieme puissance du diametre de resolution. Pour certaines repartitions du radioisotope, il est possible de deduire analytiquement une valeur optimum du diametre de resolution. Toutefois, avec la plupart des ensembles, cette valeur optimum doit etre determinee par approximations successives. Dans ce cas, les problemes qui se posent sont analogues a ceux que pose la determination d'une repartition dans d'autres domaines. L'auteur a etabli un programme pour calculatrice, qui doit permettre de determiner plus facilement la resolution optimum pour differents types de repartitions. La calculatrice utilisee est le seul appareil de ce genre qui comporte une memoire intermediaire a disques et une tete de lecture a tube a rayons cathodiques. Les resultats pourront etre appliques a l'etude d'un grand nombre d'ensembles de scintigraphic. (author) [Spanish] Todas las tecnicas de exploracion radioisotopica con colimadores enfocados, detectores de positrones o camaras de centelleo de los modelos m as recientes plantean ciertos problemas basicos. Su exito depende en gran medida de la eleccion acertada de varias parametros del dispositivo de colimacion, el m as importante de los cuales es el poder de resolucion. El autor examina la relacion que existe entre el poder de resolucion optimo, por una parte, y, por otra, el contenido de radioisotopes y su distribucion. La exploracion radioisotopica puede considerarse como un medio para acopiar y presentar ciertos dates. La informaeion primaria se refiere a la distribucion original del radioisotope. El colimador y el detector cqnstituyen el mecanismo de transferencia de la informaeion y el gammagrama final presenta los datos resultantes. Como en todas las tecnicas de esa indole, el gammagrama solo recoge una pequefia parte de la informaeion. Puede demostrarse que cuando se utiliza un colimador enfocado y una camara de centelleo, el numero de impulsos por superficie de resolucion varia como la cuarta potencia de la distancia de resolucion. Para ciertas distribuciones del radioisotopo es possible deducir analfticamente un valor optimo de la distancia de resolucion. Sin embargo, para la mayoria de los sistemas de colimacion el poder de resolucion optimo debe determinate por tanteo. En este caso los problemas son analogos a los que plantea la identificacion de esquemas en otras disciplinas. El autor ha preparado un programa para calculadora destinado a determinar mas facilmente el poder de resolucion optimo correspondiente a diverses esquemas. La calculadora utilizada es la unica que posee una memoria intermedia sobre disco y un tubo de rayos catodicos para la lectura. Los resultados asi obtenidos son de validez general para el disefio de diversos dispositivos de exploracion centelleografica. (author) [Russian] Vse metody skennirovanija kak s ispol'zovaniem fokusirujushhih kollimatorov, pozitronnyh detektorov, tak i novyh metodov s primeneniem kamery, vydvigajut opredelennye osnovnye problemy. Uspeshnoe primenenie jetih metodov zavisit v bol'shoj stepeni ot pravil'nogo* vybora razlichnyh parametrov kollimirujushhih sistem, iz kotoryh naibolee vazhnym javljaetsja razre- shenie. V nastojashhem doklade obsuzhdaetsja vzaimootnoshenie optimal'nogo razreshenija i soderzhanija h raspredelenija radioizotopov. Radioijeotopnoe skennirovanie mozhno rassmatrivat' kak process sbora informacii i predstavlenija dannyh. Pervichnaja informacija zavisit ot pervonachal'nogo raspredele- nija radioizotopov. Kollimator i sistema detektirovanija obespechivajut mehanizm pereda- chi informacii, a okonchatel'naja skennogramma daet rezul'tirujushhuju informaciju. V sluchae primenenija vseh jetih metodov lish' nebol'shaja chast' informacii popadaet na okonchatel'nuju skennogrammu. Mozhno videt', chto dlja sistemy fokusirujushhego kollimatora i scintilljacionnoj ka- mery chislo otschetov na ploshhad' razreshenija kolebletsja kak chetvertaja stepen' rasstojanija razreshenija. Dlja nekotoryh vidov raspredelenija izotopov mozhno poluchit' analiticheski optimal'nuju velichinu rasstojanija razreshenija. Odnako dlja bol'shinstva sistem optimal'- noe razreshenie dolzhno opredeljat'sja opytnym putem i s pogreshnostjami. Nastojashhie prob- lemy analogichny problemam rasshifrovki snimkov v drugih oblastjah. Programma vychisli- tel'noj mashiny byla podgotovlena s tem, chtoby sodejstvovat' opredeleniju optimal'nogo razreshenija dlja razlichnyh modelej. Nastojashhaja vychislitel'naja mashina javljaetsja unikal'noj, poskol'ku v nej imeetsja promezhutochnyj otsek dlja diska i dlja schityvanija jelektronno-luchevoj trubki. Rezul'taty primenimy k konstrukcii mnogih skennirujushhih sistem. (author)}
place = {IAEA}
year = {1964}
month = {Oct}
}