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A Theory of Radioisotope Scanning Systems; Une Theorie des Systemes de Scintigraphoe au Moyen des Radioisotopes; Teoriya sistem radioizotopnogo skennirovaniya; Teoria de los Sistemas de Exploracion Radioisotopica

Abstract

The principal goal of a general theory of scanning systems is the prediction and evaluation of the performance of hypothetical systems, optimally designed for specific scanning applications, e.g. brain-tumour detection. Such a theory should provide quantitative answers to such questions as ''How does a scanning system designed for I{sup 131} radiation compare with one designed for Hg{sup 203} in detecting brain tumours of a certain size, depth, etc.?'' This paper attempts to organize the various components of such a theory and to derive equations which relate the biological and physical parameters which must be considered. These include tumour size, depth, uptake ratio, collimator sensitivity, resolution, focal length, scan area, time, reliability, etc. Central to such a theory is a criterion or figure of merit which can be computed for any system and used for comparison of different systems. Figures of merit based on visual perception and information, theory are discussed and one based on statistics is adopted. This figure of merit is a function of detector sensitivity and resolution, which are treated in detail. Collimator response to point, plane, and volume distributions of radioactivity is discussed in detail. The total response [E{sub t} = E(l+P+S)] of a collimated detector viewing  More>>
Authors:
Beck, R. N. [1] 
  1. Argonne Cancer Research Hospital, University of Chicago, Chicago, IL (United States)
Publication Date:
Oct 15, 1964
Product Type:
Conference
Report Number:
IAEA-SM-51/52
Resource Relation:
Conference: Symposium on medical radioisotope scanning, Athens (Greece), 20-24 Apr 1964; Other Information: 19 refs., 7 figs.; Related Information: In: Medical Radioisotope Scanning. Vol. I. Proceedings of the Symposium on Medical Radioisotope Scanning| 574 p.
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; BRAIN; COLLIMATORS; COMPARATIVE EVALUATIONS; DESIGN; GAMMA RADIATION; IODINE 131; MERCURY 203; NUCLEAR MEDICINE; PERFORMANCE; POINT SOURCES; RADIOACTIVITY; RADIOISOTOPE SCANNING; RELIABILITY; SCINTILLATION COUNTERS; SENSITIVITY
OSTI ID:
22127627
Research Organizations:
International Atomic Energy Agency, Vienna (Austria)
Country of Origin:
IAEA
Language:
English
Other Identifying Numbers:
Other: ISSN 0074-1884; TRN: XA13M3040082706
Submitting Site:
INIS
Size:
page(s) 35-55
Announcement Date:
Sep 12, 2013

Citation Formats

Beck, R. N. A Theory of Radioisotope Scanning Systems; Une Theorie des Systemes de Scintigraphoe au Moyen des Radioisotopes; Teoriya sistem radioizotopnogo skennirovaniya; Teoria de los Sistemas de Exploracion Radioisotopica. IAEA: N. p., 1964. Web.
Beck, R. N. A Theory of Radioisotope Scanning Systems; Une Theorie des Systemes de Scintigraphoe au Moyen des Radioisotopes; Teoriya sistem radioizotopnogo skennirovaniya; Teoria de los Sistemas de Exploracion Radioisotopica. IAEA.
Beck, R. N. 1964. "A Theory of Radioisotope Scanning Systems; Une Theorie des Systemes de Scintigraphoe au Moyen des Radioisotopes; Teoriya sistem radioizotopnogo skennirovaniya; Teoria de los Sistemas de Exploracion Radioisotopica." IAEA.
@misc{etde_22127627,
title = {A Theory of Radioisotope Scanning Systems; Une Theorie des Systemes de Scintigraphoe au Moyen des Radioisotopes; Teoriya sistem radioizotopnogo skennirovaniya; Teoria de los Sistemas de Exploracion Radioisotopica}
author = {Beck, R. N.}
abstractNote = {The principal goal of a general theory of scanning systems is the prediction and evaluation of the performance of hypothetical systems, optimally designed for specific scanning applications, e.g. brain-tumour detection. Such a theory should provide quantitative answers to such questions as ''How does a scanning system designed for I{sup 131} radiation compare with one designed for Hg{sup 203} in detecting brain tumours of a certain size, depth, etc.?'' This paper attempts to organize the various components of such a theory and to derive equations which relate the biological and physical parameters which must be considered. These include tumour size, depth, uptake ratio, collimator sensitivity, resolution, focal length, scan area, time, reliability, etc. Central to such a theory is a criterion or figure of merit which can be computed for any system and used for comparison of different systems. Figures of merit based on visual perception and information, theory are discussed and one based on statistics is adopted. This figure of merit is a function of detector sensitivity and resolution, which are treated in detail. Collimator response to point, plane, and volume distributions of radioactivity is discussed in detail. The total response [E{sub t} = E(l+P+S)] of a collimated detector viewing a large distributed source consists of three components produced by gamma-rays which enter the collimator (1) ''geometrically'' or properly (E), (2) by penetrating the collimator septa (EP), and (3) by scattering in the source or collimator (ES). Exact equations for these components are very complex for multi-channel collimators. Useful approximate expressions are derived for E, P, and S; the limitations of these expressions are discussed. Collimator resolution, as defined by some fraction of the width of the point-source response curve, is inadequate for predicting the response to a distributed source. An analogous situation exists in optics where ''it has been increasingly realized that the advantages of resolving power as a criterion of quality are largely illusory''. Borrowing from that field, the concept of ''sine wave response'' is introduced to define resolution of collimated scintillation detectors for d istributed sources. (author) [French] Le principal objet d'une theorie generale des systemes de scintigraphie est de predire et d'evaluer les performances de systemes hypothetiques concus a des fins bien determinees, par exemple pour la detectiondes tumeurs cerebrales. Une telle theorie devrait donner des responses quantitatives a des questions telles que la suivante: 'Pour la detection de tumeurs cerebrales d'une certaine dimension, profondeur, etc., faut-il utiliser un scintigraphe concu pour u'I ou pour {sup 203}Hg?' L'auteur cherche a coordonner les divers elements d'une telle theorie et a etablir des equations exprimant les rapports entre les parametres biologiques et physiques a considerer: dimension et profondeur de la tumeur, taux de fixation, sensibilite du collimateur, pouvoir de resolution, distance focale, surface du scintigramme, temps d'exploration, fiabilite, etc. L'element essentiel de cette theorie est un critere ou indice de qualite pouvant etre calcule pour n'importe quel systeme et utilise pour la comparaison de divers systemes. L'auteur discute des indices de qualite fondes sur la perception visuelle et la theorie de l'information et adopte un indice fonde sur la statistique. Cet indice est une fonction de la sensibilite et de la resolution du detecteur; l'une et l'autre sont etudiees de maniere detaillee. L'auteur analyse la reponse du collimateur pour des sources de radioactivite ponctuelles et pour des sources distribuees dans un plan ou dans l'espace. La reponse totale [E{sub t} = E(l+P+S)] d'un detecteur.collimate, dirige sur une source de grande surface, est la somme de trois composantes dues aux rayons gamma qui penetrent dans le collimateur: a)'geometriquement'ou de facon normale (E); b) a travers les parois du collimateur (EP); c) par dispersion dans la source ou l e collimateur (ES). Dans le cas des collimateurs a canaux multiples, les equations exactes pour ces composantes sont tres complexes. Des valeurs approchees, d'interet pratique, sont donnees pour E, P et S; l'auteur discute les conditions dans lesquelles on peut les utiliser. La resolution du collimateur, definie par une fraction de la largeur de la courbe de reponse pour une source ponctuelle, ne suffit pas pour prevoir la reponse pour une source en volume. Une situation analogue se presente en optique ou ' l'on comprend de mieux en mieux que les avantages du pouvoir de resolution comme critere de qualite sont en grande partie illusoires'. S'inspirant de cette consideration, l'auteur introduit le concept dela 'reponseauneondesinusoiedale' pour definir la resolution des detecteurs a scintillation collimates pour les sources non ponctuelles. (author) [Spanish] El principal objetivo de una teoria general de los sistemas de exploracion radioisotopica es predecir y evaluar el rendimiento de sistemas hipoteticos concebidos para fines bien determinados, por ejemplo, para la deteccion de tumores cerebrales. Dicha teori'a deberia dar respuestas cuantitativas a preguntas taies como la siguiente: 'Para la deteccion de tumores cerebrales de un cierto tamaño, profundidad, etc., es necesario utilizar un aparato de exploracion concebido para el {sup 131}I o para el {sup 203}Hg?'. El autor trata de coordinar los diversos elementos de uiia teoria de esa clase y de establecer ecuaciones que expresen las relaciones entre los parametras biologicos y fisicos que deben tenerse en cuenta: tamaflo y profundidad del tumor, indice de captacion, sensibilidad del colimador, poder de resolucion, distancia focal, superficie del centelleograma, tiempo de exploracion, exactitud de los resultados, etc. El elemento esencial de esta teoria es un criterio o indice de calidad que se pueda calculai para cualquier sistema y sirva para comparer entre si sistemas diversos. El autor discute indices de calidad basados en la percepcion Visual y en la teorfa de la informaeion, y adopta uno basado en la estadistica. Este indice es una function de la sensibilidad y del poder de resolucion del detector; los dos son estudiados detalladamente. El autor analiza la respuesta del colimador a fuentes radiactivas puntuales, planas y tridimensionales. La respuesta total [E{sub t} = E(l+P+S)] de un detector colimado dirigido sobre una fuente de gran extension es la suma de tres ccmponentes debidos a los rayos gamma que penetran en el colimador a) 'geometricamente' o de una manera normal (E); b) atravesando los tabiques del colimador (EP); c) por dispersion en la fuente o en el colimador (ES). Las ecuaciones exaetas de estos componentes son muy complejas para los colimadores multicanales. En la memoria se dan valores aproximados de interes practico para E, P y S, y se discuten las condiciones en que estos valores pueden utilizarse. El poder de resolucion del colimador, definido por una fraeeion de la anebura de la curva de respuesta a una fuente puntual, no basta para prever la respuesta a una fuente tridimensional externa. En optica se produce una situaeion aniloga y 'cadavezsehace mas patente que las ventajas del poder de resolucion como criterio de la calidad son en gran parte ilusorias'. Inspirandose en esta consideracion el autor introduce el concepto de la 'respuesta a una onda sinusoidal' para definir el poder de resolucion de los detectores de centelleo colimados para fuentes no puntuales. (author) [Russian] Glavnoj cel'ju obshhej teorii sistem skennirovanija javljaetsja predskazanie i ocenka harakteristiki gipotetiches- kih sistem, optimal'no prednaznachennyh dlja konkretnyh celej primenenija skennirovanija; naprimer dlja obnaruzhenija opuholej mozga. Takaja teorija dolzhna dat' kolichestvennye otvety na vopros: ''Kak sravnivat' sistemu skennirovanija, prednaznachennuju dlja joda-131 s sistemoj, prednaznachennoj dlja rtuti-203 pri obnaruzhenii opuholej mozga opredelennogo razmera, glubiny i t . d . ? V doklade delajutsja popytki sistematizacii razlichnyh komponentov takoj teorii i vyvedenija uravnenij dlja rassmatrivaemyh biologicheskih i fizicheskih parametrov. Oni vkljuchajut razmer opuholej, glubinu, kojefficient pogloshhenija, chuvstvitel'nost' kollima- tora, razreshajushhuju sposobnost', fokusnoe rasstojanie, ploshhad' skennirovanija, vremja, na- dezhnost' it. d. Osnovoj takoj teorii javljaetsja kriterij ili cifrovye parametry, kotorye mogut byt' vychisleny dlja ljuboj sistemy i ispol'zovany dlja sravnenija razlichnyh sistem. Ob- suzhdajutsja cifrovye parametry, osnovannye na vizual'nom vosprijatii i teorii informa- cii i prinimaetsja odin iz nih, imejushhij statisticheskuju osnovu. Jeti cifrovye parametry javljajutsja funkciej chuvstvitel'nosti detektora i e g o razreshajushhej sposobnosti, kotorye podrobno rassmatrivajutsja. Podrobno obsuzhdaetsja harakteristika kollimatora otnositel'no mesta, urovnja i ob{sup -} ema raspredelenija radioaktivnosti. Obshhaja harakteristika [E{sub t} = E ( + P + S)] detektora, snabzhennogo kollimatorom, napravlennogo na krupnyj raspredelennyj istochnik, sostoit iz treh komponentov, proizvodimyh gamma-luchami, kotorye popadajut v kollimator 1) ''geo- metricheski'' ili pravil'no (E), 2) putem proniknovenija cherez peregorodki kollimatora (ER), i putem rassejanija v istochnike ili kollimatore (ES). Tochnye uravnenija dlja jetih kompo- nentov javljajutsja ochen' slozhnymi dlja mnogokanal'nyh kollimatorov. Vyvedeny poleznye priblizitel'nye vyrazhenija dlja E, R i S; obsuzhdaetsja ogranichennost' primenenija jetih vyrazhenij. Razreshajushhaja sposobnost' kollimatora, opredeljaemaja nekotoroj frakciej shiroty krivoj chuvstvitel'nosti k tochechnomu istochniku, ne adekvatna dlja predskazanija chuvstvi- tel'nosti k raspredelennomu istochniku. 'Analogichnoe polozhenie sushhestvuet v optike, gde ''vse chashhe priznaetsja, chto preimushhestva razreshajushhej moshhnosti kak kriterija kachestva jav- ljajutsja v znachitel'noj stepeni illjuzornymi'' . Po analogii vvoditsja koncepcija ''sinusoidnaja volnovaja harakteristika'' dlja opredelenija razreshajushhej sposobnosti scintilljacionnyh de- tektorov, snabzhennyh kollimatorom, v otnoshenii raspredelennyh istochnikov. (author)}
place = {IAEA}
year = {1964}
month = {Oct}
}