• Title/Summary/Keyword: 조준형

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Evaluation of Validity Thyroid Scintigraphy Using Parallel Hole Collimator (갑상샘 신티그래피 검사 시 평행다공형 조준기 적용의 유효성 평가)

  • Su-Young Park;Ji-Youn Kim;Sung-Min Ahn
    • Journal of the Korean Society of Radiology
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    • v.18 no.1
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    • pp.27-36
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    • 2024

  • In this study, When acquisition thyroid scintigraphy images, a parallel hole collimator was applied, and the difference from the pinhole collimator was quantitatively analyzed under each image acquisition condition. Visual size, resolution, sensitivity, signal to noise ratio (SNR), and contrast to noise ratio (CNR) were evaluated using thyroid phantom and point source. When comparing visual size, it was confirmed that an image similar to the size of the pinhole collimator could be obtained only when a magnification ratio of about 2.00 to 2.09 times when applying a parallel hole collimator. There was no tendency in FWHM(mm) measurement using a point source, and sensitivity was high in the parallel hole collimator. SNR and CNR were high when using a low magnification ratio, matrix size of 128×128, and a parallel hole collimator. In images of similar size to the naked eye, when the matrix size was the same, both SNR and CNR were high in the pinhole collimator. Therefore, when performing a thyroid scintigraphy test, if appropriate conditions are set according to the situation of each hospital and a parallel hole collimator is applied, it can be a good option in terms of equipment utilization and work efficiency.

  • https://doi.org/10.7742/jksr.2024.18.1.27 인용 PDF HTML

Optimization of Parallel-Hole Collimator for Small Gamma Camera Based on Pixellated Crystal Array (배열형 섬광결정을 이용한 소형 감마카메라의 평행구멍형 조준기 최적화 연구)

  • Chung, Yong-Hyun;Beak, Cheol-Ha;Lee, Seung-Jae;Park, Jin-Hyung
    • Progress in Medical Physics
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    • v.19 no.4
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    • pp.291-297
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    • 2008

  • The purpose of this study is to optimize a parallel-hole collimator for small gamma camera having the pixellated crystal array and evaluate the effect of crystal-collimator misalignment on the image quality using a simulation tool GATE (Geant4 Application for Tomographic Emission). The spatial resolution and sensitivity were measured for the various size of hexagonal-hole and matched square-hole collimators with a Tc-99m point source and the uniformity of flood image was estimated as a function of the angle between crystal array and collimator by misalignment. The results showed that the spatial resolution and sensitivity were greatly improved by using the matched collimator and the uniformity was reduced by crystal-collimator misalignment.

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