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The Study of Error for Analysis in Dynamic Image from the Error of Count Rates in NaI (Tl) Scintillation Camera  

Oh, Joo-Young (Department of Nuclear Medicine, Severance Hospital, Yonsei University)
Kang, Chun-Goo (Department of Nuclear Medicine, Severance Hospital, Yonsei University)
Kim, Jung-Yul (Department of Nuclear Medicine, Severance Hospital, Yonsei University)
Park, Hoon-Hee (Department of Radiological Technology, Shingu college)
Oh, Ki-Baek (Department of Nuclear Medicine, Severance Hospital, Yonsei University)
Kim, Jae-Sam (Department of Nuclear Medicine, Severance Hospital, Yonsei University)
Publication Information
Journal of radiological science and technology / v.36, no.4, 2013 , pp. 291-297 More about this Journal
Abstract
This study is aimed to evaluate the effect of $T_{1/2}$ upon count rates in the analysis of dynamic scan using NaI (Tl) scintillation camera, and suggest a new quality control method with this effects. We producted a point source with $^{99m}TcO_4^-$ of 18.5 to 185 MBq in the 2 mL syringes, and acquired 30 frames of dynamic images with 10 to 60 seconds each using Infinia gamma camera (GE, USA). In the second experiment, 90 frames of dynamic images were acquired from 74 MBq point source by 5 gamma cameras (Infinia 2, Forte 2, Argus 1). There were not significant differences in average count rates of the sources with 18.5 to 92.5 MBq in the analysis of 10 to 60 seconds/frame with 10 seconds interval in the first experiment (p>0.05). But there were significantly low average count rates with the sources over 111 MBq activity at 60 seconds/frame (p<0.01). According to the second analysis results of linear regression by count rates of 5 gamma cameras those were acquired during 90 minutes, counting efficiency of fourth gamma camera was most low as 0.0064%, and gradient and coefficient of variation was high as 0.0042 and 0.229 each. We could not find abnormal fluctuation in $x^2$ test with count rates (p>0.02), and we could find the homogeneity of variance in Levene's F-test among the gamma cameras (p>0.05). At the correlation analysis, there was only correlation between counting efficiency and gradient as significant negative correlation (r=-0.90, p<0.05). Lastly, according to the results of calculation of $T_{1/2}$ error from change of gradient with -0.25% to +0.25%, if $T_{1/2}$ is relatively long, or gradient is high, the error increase relationally. When estimate the value of 4th camera which has highest gradient from the above mentioned result, we could not see $T_{1/2}$ error within 60 minutes at that value. In conclusion, it is necessary for the scintillation gamma camera in medical field to manage hard for the quality of radiation measurement. Especially, we found a tendency that count rate changes over time at this study, and we proved that it can effect $T_{1/2}$. And also, there is need of appropriate phantoms and the method of quality management like this study, because there are not any advice or limitation degrees for domestic medical purpose scintillation camera.
Keywords
Point source; Count rate; Quality control; $T_{1/2}$; Gradient;
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Times Cited By KSCI : 1  (Citation Analysis)
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1 Chang-Soon Koh : Nucear Medicine, Third Edition, Korea Medical Book, 37-45, 2008
2 Rehm, P. K.: Scintigraphic evaluation of gastric emptying, Applied Radiology, 316, 26-32, 2002
3 Su-Yong Lee : Radiation Detection and Measurement, Second Edition, Gijeon Research, 145-150, 347-349, 2008
4 Gyuseong Cho : Gamma-ray Detectors for Nuclear Medical Imaging Instruments, Nucl Med Mol Imaging, 42, 88-97, 2008
5 Murphy, Paul H: Acceptance testing and quality control of gamma cameras, including SPECT, Journal of nuclear Medicine, 28.7, 1221-1227, 1987
6 Fiorini, C., Bellini, M., Gola, A., et al: A Monilithic Array of 77 Silicon Drift Detectors for X-Ray Spectroscopy and Gamma-Ray Imaging Applications, IEEE Trans Nucl Sci, 52:1165-70, 2005   DOI   ScienceOn
7 Zanzonico, Pat: Routine quality control of clinical nuclear medicine instrument: a brief review, Journal of nuclear medicine, 49.7, 1114-1131, 2008   DOI   ScienceOn
8 Lancaster, J. L., Kopp, D. T., Lasher, J. S., Blumhardt, R.: Practical gamma camera quality control with a four-point phantom, Journal of nuclear medicine, 26.3, 300-307, 1985
9 Anigstein, R., Olsher, R. H., Branch, R. S., Green, P.: Use of Radiation Detection, Measuring, and Imaging Instruments to Assess Internal Contamination from Inhaled Radionuclides. Part II: Field Tests and Monte Carlo Simulations Using Anthropomorphic Phantoms, Contract, 200-2002, 00367, 2007
10 Brolin, G., Gleisner, K. S., Ljungberg, M.: Dynamic (99m)Tc-MAG3 renography: images for quality control obtained by combining pharmacokinetic modelling, an anthropomorphic computer phantom and Monte Carlo simulated scintillation camera imaging, Phys Med Biol, 21;58(10), 3145-61, 2013   DOI   ScienceOn
11 Busemann Sokole, E., Płachcinska, A., Britten, A., Lyra Georgosopoulou, M., Tindale, W., Klett, R.: Routine quality control recommendations for nuclear medicine instrumentation, European journal of nuclear medicine and molecular imaging, 37.3, 662-671, 2010   DOI