• 제목/요약/키워드: single photon computed tomography

검색결과 159건 처리시간 0.022초

Preclinical evaluation using functional SPECT imaging of 123I-metaiodobenzylguanidine (mIBG) for adrenal medulla in normal mice

  • Yiseul Choi;Hye Kyung Chung;Sang Keun Woo;Kyo Chul Lee;Seowon Kang;Seowon Kang;Joo Hyun Kang;Iljung Lee
    • 대한방사성의약품학회지
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    • 제7권2호
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    • pp.93-98
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    • 2021
  • meta-iodobenzylguanidine is one of the norepinephrine analogs and reuptakes together with norepinephrine with norepinephrine transporter. The radioiodinated ligand, 123I-meta-iodobenzylguanidine, is the most widely used for single photon emission computed tomography imaging to diagnose functional abnormalities and tumors of the sympathetic nervous system. In this study, we performed cellular uptake studies of 123I-meta-iodobenzylguanidine in positive- and negative-norepinephrine transporter cells in vitro to verify the uptake activity for norepinephrine transporter. After 123I-meta-iodobenzylguanidine was injected via a tail vein into normal mice, Single photon emission computed tomography/computed tomography images were acquired at 1 h, 4 h, and 24 h post-injection, and quantified the distribution in each organ including the adrenal medulla as a norepinephrine transporter expressing organ. In vitro cell study showed that 123I-meta-iodobenzylguanidine specifically uptaked via norepinephrine transporter, and significant uptake of 123I-meta-iodobenzylguanidine in the adrenal medulla in vivo single photon emission computed tomography images. These results demonstrated that single photon emission computed tomography imaging with 123I-meta-iodobenzylguanidine were able to quantify the biodistribution in vivo in the adrenal medulla in normal mice.

Experimental evaluation of fuel rod pattern analysis in fuel assembly using Yonsei single-photon emission computed tomography (YSECT)

  • Choi, Hyung-joo;Cheon, Bo-Wi;Baek, Min Kyu;Chung, Heejun;Chung, Yong Hyun;You, Sei Hwan;Min, Chul Hee;Choi, Hyun Joon
    • Nuclear Engineering and Technology
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    • 제54권6호
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    • pp.1982-1990
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    • 2022
  • The purpose of this study was to verify the possibility of fuel rod pattern analysis in a fresh fuel assembly using the Yonsei single-photon emission computed tomography (YSECT) system. The YSECT system consisted of three main parts: four trapezoidal-shaped bismuth germanate scintillator-based 64-channel detectors, a semiconductor-based multi-channel data acquisition system, and a rotary stage. In order to assess the performance of the prototype YSECT, tomographic images were obtained for three representative fuel rod patterns in the 6 × 6 array using two representative image-reconstruction algorithms. The fuel-rod patterns were then assessed using an in-house fuel rod pattern analysis algorithm. In the experimental results, the single-directional projection images for those three fuel-rod patterns well discriminated each fuel-rod location, showing a Gaussian-peak-shaped projection for a single 10 mm-diameter fuel rod with 12.1 mm full-width at half maximum. Finally, we successfully verified the possibility of the fuel rod pattern analysis for all three patterns of fresh fuel rods with the tomographic images obtained by the rotational YSECT system.

Improvement of signal and noise performance using single image super-resolution based on deep learning in single photon-emission computed tomography imaging system

  • Kim, Kyuseok;Lee, Youngjin
    • Nuclear Engineering and Technology
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    • 제53권7호
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    • pp.2341-2347
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    • 2021
  • Because single-photon emission computed tomography (SPECT) is one of the widely used nuclear medicine imaging systems, it is extremely important to acquire high-quality images for diagnosis. In this study, we designed a super-resolution (SR) technique using dense block-based deep convolutional neural network (CNN) and evaluated the algorithm on real SPECT phantom images. To acquire the phantom images, a real SPECT system using a99mTc source and two physical phantoms was used. To confirm the image quality, the noise properties and visual quality metric evaluation parameters were calculated. The results demonstrate that our proposed method delivers a more valid SR improvement by using dense block-based deep CNNs as compared to conventional reconstruction techniques. In particular, when the proposed method was used, the quantitative performance was improved from 1.2 to 5.0 times compared to the result of using the conventional iterative reconstruction. Here, we confirmed the effects on the image quality of the resulting SR image, and our proposed technique was shown to be effective for nuclear medicine imaging.

Newly-designed adaptive non-blind deconvolution with structural similarity index in single-photon emission computed tomography

  • Kyuseok Kim;Youngjin Lee
    • Nuclear Engineering and Technology
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    • 제55권12호
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    • pp.4591-4596
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    • 2023
  • Single-photon emission computed tomography SPECT image reconstruction methods have a significant influence on image quality, with filtered back projection (FBP) and ordered subset expectation maximization (OSEM) being the most commonly used methods. In this study, we proposed newly-designed adaptive non-blind deconvolution with a structural similarity (SSIM) index that can take advantage of the FBP and OSEM image reconstruction methods. After acquiring brain SPECT images, the proposed image was obtained using an algorithm that applied the SSIM metric, defined by predicting the distribution and amount of blurring. As a result of the contrast to noise ratio (CNR) and coefficient of variation evaluation (COV), the resulting image of the proposed algorithm showed a similar trend in spatial resolution to that of FBP, while obtaining values similar to those of OSEM. In addition, we confirmed that the CNR and COV values of the proposed algorithm improved by approximately 1.69 and 1.59 times, respectively, compared with those of the algorithm involving an inappropriate deblurring process. To summarize, we proposed a new type of algorithm that combines the advantages of SPECT image reconstruction techniques and is expected to be applicable in various fields.

단일광자방출 전산화단층촬영상에서 재구성 필터에 의한 정량화 오차에 관한 연구 (A Study on the Quantification Error due to the Reconstruction Filters in Single Photon Emission Computed Tomography(SPECT))

  • 곽철은;정준기
    • 대한의용생체공학회:의공학회지
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    • 제12권1호
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    • pp.43-48
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    • 1991
  • As the computerized methods and equipments In nuclear medicine imaging increases, quantitative information is needed on the single photon emission computed tomographic Images as well as on the conventional nuclear medicine images. In this paper, the authors investigated the effect of several clinician - friendly reconstrution filters on the resultant transverse slices of backprojected Profiles of radioisotope distribution from the Quantitative point of view, and reduced the filter parameters such as cutoff frequency and order of filter which are neces mary to minimize the quantification error using computer-generated phantoms.

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Optimization of Yonsei Single-Photon Emission Computed Tomography (YSECT) Detector for Fast Inspection of Spent Nuclear Fuel in Water Storage

  • Hyung-Joo Choi;Hyojun Park;Bo-Wi Cheon;Kyunghoon Cho;Hakjae Lee;Yong Hyun Chung;Yeon Soo Yeom;Sei Hwan You;Hyun Joon Choi;Chul Hee Min
    • Journal of Radiation Protection and Research
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    • 제49권1호
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    • pp.29-39
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    • 2024
  • Background: The gamma emission tomography (GET) device has been reported a reliable technique to inspect partial defects within spent nuclear fuel (SNF) of pin-by-pin level. However, the existing GET devices have low accuracy owing to the high attenuation and scatter probability for SNF inspection condition. The purpose of this study is to design and optimize a Yonsei single-photon emission computed tomography version 2 (YSECT.v.2) for fast inspection of SNF in water storage by acquisition of high-quality tomographic images. Materials and Methods: Using Geant4 (Geant4 Collaboration) and DETECT-2000 (Glenn F. Knoll et al.) Monte Carlo simulation, the geometrical structure of the proposed device was determined and its performance was evaluated for the 137Cs source in water. In a Geant4-based assessment, proposed device was compared with the International Atomic Energy Agency (IAEA)-authenticated device for the quality of tomographic images obtained for 12 fuel sources in a 14 × 14 Westinghouse-type fuel assembly. Results and Discussion: According to the results, the length, slit width, and septal width of the collimator were determined to be 65, 2.1, and 1.5 mm, respectively, and the material and length of the trapezoidal-shaped scintillator were determined to be gadolinium aluminum gallium garnet and 45 mm, respectively. Based on the results of performance comparison between the YSECT.v.2 and IAEA's device, the proposed device showed 200 times higher performance in gamma-detection sensitivity and similar source discrimination probability. Conclusion: In this study, we optimally designed the GET device for improving the SNF inspection accuracy and evaluated its performance. Our results show that the YSECT.v.2 device could be employed for SNF inspection.

Basic Physical Principles and Clinical Applications of Computed Tomography

  • Jung, Haijo
    • 한국의학물리학회지:의학물리
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    • 제32권1호
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    • pp.1-17
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    • 2021
  • The evolution of X-ray computed tomography (CT) has been based on the discovery of X-rays, the inception of the Radon transform, and the development of X-ray digital data acquisition systems and computer technology. Unlike conventional X-ray imaging (general radiography), CT reconstructs cross-sectional anatomical images of the internal structures according to X-ray attenuation coefficients (approximate tissue density) for almost every region in the body. This article reviews the essential physical principles and technical aspects of the CT scanner, including several notable evolutions in CT technology that resulted in the emergence of helical, multidetector, cone beam, portable, dual-energy, and phase-contrast CT, in integrated imaging modalities, such as positron-emission-tomography-CT and single-photon-emission-computed-tomography-CT, and in clinical applications, including image acquisition parameters, CT angiography, image adjustment, versatile image visualizations, volumetric/surface rendering on a computer workstation, radiation treatment planning, and target localization in radiotherapy. The understanding of CT characteristics will provide more effective and accurate patient care in the fields of diagnostics and radiotherapy, and can lead to the improvement of image quality and the optimization of exposure doses.