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Titolo:
Nonuniform transmission in brain SPECT using Tl-201, Gd-153, and Tc-99m static line sources: Anthropomorphic dosimetry studies and influence on brainquantification
Autore:
Van Laere, K; Koole, M; Kauppinen, T; Monsieurs, M; Bouwens, L; Dierck, R;
Indirizzi:
State Univ Ghent Hosp, Div Nucl Med, B-9000 Ghent, Belgium State Univ Ghent Hosp Ghent Belgium B-9000 cl Med, B-9000 Ghent, Belgium State Univ Ghent, Med Imaging & Signal Proc Dept, B-9000 Ghent, Belgium State Univ Ghent Ghent Belgium B-9000 l Proc Dept, B-9000 Ghent, Belgium State Univ Ghent, Lab Stand Dosimetry, B-9000 Ghent, Belgium State Univ Ghent Ghent Belgium B-9000 d Dosimetry, B-9000 Ghent, Belgium Kuopio Univ Hosp, Dept Clin Physiol & Nucl Med, SF-70210 Kuopio, Finland Kuopio Univ Hosp Kuopio Finland SF-70210 l Med, SF-70210 Kuopio, Finland
Titolo Testata:
JOURNAL OF NUCLEAR MEDICINE
fascicolo: 12, volume: 41, anno: 2000,
pagine: 2051 - 2062
SICI:
0161-5505(200012)41:12<2051:NTIBSU>2.0.ZU;2-T
Fonte:
ISI
Lingua:
ENG
Soggetto:
CEREBRAL BLOOD-FLOW; ATTENUATION CORRECTION; SIMULTANEOUS EMISSION; NUCLEAR-MEDICINE; ORDERED SUBSETS; SCATTER; SINGLE; COMPENSATION; TOMOGRAPHY; SYSTEM;
Keywords:
transmission CT; dosimetry; brain SPECT; quantification;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Clinical Medicine
Life Sciences
Citazioni:
39
Recensione:
Indirizzi per estratti:
Indirizzo: Van Laere, K State Univ Ghent Hosp, Div Nucl Med, P7,De Pintelaan 185, B-9000 Ghent, Belgium State Univ Ghent Hosp P7,De Pintelaan 185 Ghent BelgiumB-9000
Citazione:
K. Van Laere et al., "Nonuniform transmission in brain SPECT using Tl-201, Gd-153, and Tc-99m static line sources: Anthropomorphic dosimetry studies and influence on brainquantification", J NUCL MED, 41(12), 2000, pp. 2051-2062

Abstract

Nonuniform attenuation correction in brain SPECT can be done routinely by means of additional gamma transmission CT (TCT) measurements, using different commercially available line-source isotopes. Tl-201, Gd-153, and Tc-99m are among the most commonly used isotopes, depending on practical and cost-effectiveness issues. We have measured additional radiation burden from static uncollimated brain SPECT transmission sources for these isotopes. The influence of the transmission isotope on brain quantification was also measured and compared with uniform attenuation correction for phantom and human data. Full iterative transmission and emission reconstruction were comparedwith filtered backprojection techniques. Methods: Rod sources with Tl-201,Gd-153, and Tc-99m were used on a triple-head gamma camera. Dosimetry was performed using LIF TLD-100 pellets and an anthropomorphic RANDO phantom. Effective dose equivalents were calculated on the basis of measured and extrapolated absorbed doses. For brain activity measurements, a Hoffman phantomwas used. Images were corrected for scatter (triple-energy window) and were reconstructed by Chang attenuation correction and filtered backprojectionas well as full iterative reconstruction (ordered-subsets expectation maximization [OSEM]). To study the effect of inhomogeneous bone attenuation, realistic measurements were performed on 10 young, healthy volunteers with Gd-153 TCT. After stereotactic image realignment, a volume-of-interest analysis normalized to total counts was performed. Results: Brain SPECT-TCT usingTl-201, Gd-153, and Tc-99m produced total effective dose-rate equivalents of 50.3 +/- 11.2, 32.0 +/- 2.7, and 71.1 +/- 7.1 mu Sv/GBq x h, respectively, representing dose equivalents of 18.6, 11.9, and 26.3 mu Sv for a typical 20-min brain SPECT scan at maximal used source strength. Standardized quantification resulted in insignificant differences between the isotopes and methods (Chang versus OSEM) used for nonuniform correction. Iterative reconstruction enhanced image contrast and provided more accurate gray-to-white matter ratios. Between nonuniform and uniform attenuation with an optimizedattenuation coefficient, slight central discrepancies were found for volunteer studies. Significantly lower intersubject variation was found for nonuniform corrected values in infratentorial and posterior brain regions. Conclusion: Brain transmission scanning using Tl-201 Gd-153, Or Tc-99m results in limited effective radiation dose equivalents compared with the typical radiation burden. Relative brain perfusion quantification is not significantly different for the various nonuniform TCT isotopes. Iterative reconstruction improves gray-to-white contrasts but has no significant influence on brain perfusion semiquantification. Nonuniform attenuation correction decreases intersubject variability in the posterior brain regions that were compared, which may lead to improved sensitivity toward clinical applications.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 10/04/20 alle ore 02:36:05