• Title/Summary/Keyword: Nuclear medicine image

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Nuclear Medicine Physics: Review of Advanced Technology

  • Oh, Jungsu S.
    • Progress in Medical Physics
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    • v.31 no.3
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    • pp.81-98
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    • 2020
  • This review aims to provide a brief, comprehensive overview of advanced technologies of nuclear medicine physics, with a focus on recent developments from both hardware and software perspectives. Developments in image acquisition/reconstruction, especially the time-of-flight and point spread function, have potential advantages in the image signal-to-noise ratio and spatial resolution. Modern detector materials and devices (including lutetium oxyorthosilicate, cadmium zinc tellurium, and silicon photomultiplier) as well as modern nuclear medicine imaging systems (including positron emission tomography [PET]/computerized tomography [CT], whole-body PET, PET/magnetic resonance [MR], and digital PET) enable not only high-quality digital image acquisition, but also subsequent image processing, including image reconstruction and post-reconstruction methods. Moreover, theranostics in nuclear medicine extend the usefulness of nuclear medicine physics far more than quantitative image-based diagnosis, playing a key role in personalized/precision medicine by raising the importance of internal radiation dosimetry in nuclear medicine. Now that deep-learning-based image processing can be incorporated in nuclear medicine image acquisition/processing, the aforementioned fields of nuclear medicine physics face the new era of Industry 4.0. Ongoing technological developments in nuclear medicine physics are leading to enhanced image quality and decreased radiation exposure as well as quantitative and personalized healthcare.

Recent Developments in Nuclear Medicine Instrumentation (최근 핵의학 영상 기기 발전 동향)

  • Kim, Joon-Young;Choi, Yong;Kim, Jong-Ho;Im, Ki-Chun;Choe, Yearn-Seong;Lee, Kyung-Han;Kim, Sang-Eun;Kim, Byung-Tae
    • The Korean Journal of Nuclear Medicine
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    • v.32 no.6
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    • pp.471-481
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    • 1998
  • The goals of developments in nuclear medicine instrumentation are to offer a higher-quality image and to aid diagnosis, prognosis assessment or treatment planning and monitoring. It is necessary for physicists and engineers to improve or design new instrumentation and techniques, and to implement, validate, and apply these new approaches in the practice of nuclear medicine. The researches in physical properties of detectors and crystal materials and advances in image analysis technology have improved quantitative and diagnostic accuracy of nuclear medicine images. This review article presents recent developments in nuclear medicine instrumentation, including scatter and attenuation correction, new detector technology, tomographic image reconstruction methods, 511 keV imaging, dual modality imaging device, small gamma camera, PET developments, image display and analysis methods.

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Investigation of a blind-deconvolution framework after noise reduction using a gamma camera in nuclear medicine imaging

  • Kim, Kyuseok;Lee, Min-Hee;Lee, Youngjin
    • Nuclear Engineering and Technology
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    • v.52 no.11
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    • pp.2594-2600
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    • 2020
  • A gamma camera system using radionuclide has a functional imaging technique and is frequently used in the field of nuclear medicine. In the gamma camera, it is extremely important to improve the image quality to ensure accurate detection of diseases. In this study, we designed a blind-deconvolution framework after a noise-reduction algorithm based on a non-local mean, which has been shown to outperform conventional methodologies with regard to the gamma camera system. For this purpose, we performed a simulation using the Monte Carlo method and conducted an experiment. The image performance was evaluated by visual assessment and according to the intensity profile, and a quantitative evaluation using a normalized noise-power spectrum was performed on the acquired image and the blind-deconvolution image after noise reduction. The result indicates an improvement in image performance for gamma camera images when our proposed algorithm is used.

Recent Development in Text-based Medical Image Retrieval (텍스트 기반 의료영상 검색의 최근 발전)

  • Hwang, Kyung Hoon;Lee, Haejun;Koh, Geon;Kim, Seog Gyun;Sun, Yong Han;Choi, Duckjoo
    • Journal of Biomedical Engineering Research
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    • v.36 no.3
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    • pp.55-60
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    • 2015
  • An effective image retrieval system is required as the amount of medical imaging data is increasing recently. Authors reviewed the recent development of text-based medical image retrieval including the use of controlled vocabularies - RadLex (Radiology Lexicon), FMA (Foundational Model of Anatomy), etc - natural language processing, semantic ontology, and image annotation and markup.

Syntheis and $^{99m}Tc$ labeling of Ethylcystein Dimer and Its Brain SPECT Image (두뇌 혈류영상용 방사성의약품인 Ethylcystein Dimer(ECD)의 합성과 $^{99m}Tc$ 표지 및 뇌단일광자단층영상 구성)

  • Jeong, Jae-Min;Lee, Myung-Chul;Chung, Soo-Wook;Lee, Kyung-Han;Cho, Jung-Hyuck;Kwark, Cheol-Eun;Lee, Dong-Soo;Chung, June-Key;Koh, Chang-Soon
    • The Korean Journal of Nuclear Medicine
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    • v.28 no.2
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    • pp.167-171
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    • 1994
  • Ethylcystein dimer (ECD) was synthesized by dimerizatlon of L-thiazolidine-4-carboxylic acid in liquid ammania with sodium metal and successive esterification in ethanolic solution of hydrogen chlorde. The purified product was labeled with $^{99m}Tc$ in the presence of sodium glucarate(pH= 5.6) and stannous chloride. Best result was obtained from the preparation con sisting of 0.1mg ECD, $40{\mu}l$ of 0.4M sodium glucarate (pH=5.6), and $20{\mu}g$ of stannous chloride. The labeling efficiency was 90% with previous condition. The labeled $^{99m}Tc$-ECD was stable at least for 3 hours in PBS(pH=7.4) at room temperature. About 10mCi of $^{99m}Tc$-ECD was injected to normal volunteer, and SPECT image of brain was obtained by triple head camera 10 minutes after inection. The image showed similar distribution of radioactivity in brain with that of HMPAO image.

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Solution to Decrease Spatial Dose Rate in Laboratory of Nuclear Medicine through System Improvement (시스템 개선을 통한 핵의학 검사실의 공간 선량률 감소방안)

  • Moon, Jae-Seung;Shin, Min-Yong;Ahn, Seong-Cheol;Yoo, Mun-Gon;Kim, Su-Geun
    • Quality Improvement in Health Care
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    • v.20 no.1
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    • pp.60-73
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    • 2014
  • Objectives: This study aims at decreasing spatial dose rate through work improvement whilst spatial dose rate is the cause of increasing personal exposure dose which occurs in the process of handling radioisotope. Methods: From February 2013 until July 2013, divided into "before" and "after" the improvement, spatial dose rate in laboratory of nuclear medicine was measured in gamma image room, PET/CT-1 image room, and PET/CT-2 image room as its locations. The measurement time was 08:00, 12:00 and 17:00, and SPSS 21.0 USA was opted for its statistical analysis. Result: The spatial dose rate at distribution worktable, injection table, the entrance to the distribution room, and radioisotope storage box, which had showed high spatial dose rate, decreased by more than 43.7% a monthly average. The distribution worktable, that had showed the highest spatial dose rate in PET/CT-1 image room, dropped the rate to 42.3% as of July. The injection table and distribution worktable in the PET/CT-2 image room also showed the decline of spatial dose rate to 89% and 64.4%, respectively. Conclusion: By improving distribution process and introducing proper radiation shielding material, we were able to drop the spatial dose rate substantially at distribution worktable, injection table, and nuclide storage box. However, taking into account of steadily increasing amount of radioisotope used, strengthening radiation related regulations, and safe utilization of radioisotope, the process of system improvement needs to be maintained through continuous monitoring.

False-positive I-131 Scan by Contaminated Muffler in a Patient with Thyroid Carcinoma (갑상선암 환자에서 방사성 옥소로 오염된 목도리에 의한 위양성 소견)

  • Seo, Han-Kyung;Kim, Min-Woo;Jeong, Hwan-Jeong;Sohn, Myung-Hee
    • Nuclear Medicine and Molecular Imaging
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    • v.40 no.1
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    • pp.51-52
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    • 2006
  • A 39-year-old female patient who had undergone a total thyroidectomy for a papillary thyroid carcinoma underwent a whole body scan with I-131. The I-131 scan was performed 72 hours after administering 185 MBq (5 mCi) of an I-131 solution. The anterior image of the head, neck, and upper chest showed multiple areas of increased uptake in the mediastinal area considering of functional metastasis. However, radioactivity was not evident in the image taken after removing her clothes and muffler. The image obtained after placing the muffler on the pallet showed that the radioactivity was still present. It is well known that artifacts on an I-131 scan can be produced by styling hair sputum, drooling during sleep, chewing gum, and paper or a cloth handkerchief that is contaminated with the radioactive iodine from either perspiration or saliva. This activity might be mistaken for a functional metastasis. Therefore, it is essential that an image be obtained after removing the patient's clothes. In this study, artifacts due to a contaminated muffler on the I-131 scan were found. These mimicked a functional metastasis of the mediastinal area in a patient with a papillary thyroid carcinoma.

The Application of Dynamic Acquisition with Motion Correction for Static Image (동적 영상 획득 방식을 이용한 정적 영상의 움직임 보정)

  • Yoon, Seok-Hwan;Seung, Jong-Min;Kim, Kye-Hwan;Kim, Jae-Il;Lee, Hyung-Jin;Kim, Jin-Eui;Kim, Hyun-Joo
    • The Korean Journal of Nuclear Medicine Technology
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    • v.14 no.1
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    • pp.46-53
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    • 2010
  • Purpose: The static image of nuclear medicine study should be acquired without a motion, however, it is difficult to acquire static image without movement for the serious patients, advanced aged patients. These movements cause decreases in reliability for quantitative and qualitative analysis, therefore re-examination was inevitable in the some cases. Consequently, in order to improve the problem of motion artifacts, the authors substituted the dynamic acquisition technique for the static acquisition, using motion correction. Materials and Methods: A capillary tube and IEC body phantom were used. First, the static image was acquired for 60 seconds while the dynamic images were acquired with a protocol, 2 sec/frame${\times}$30 frames, under the same parameter and the frames were summed up into one image afterwards. Also, minimal motion and excessive motion were applied during the another dynamic acquisition and the coordinate correction was applied towards X and Y axis on the frames where the motion artifact occurred. But the severe blurred images were deleted. Finally, the resolution and counts were compared between the static image and the summed dynamic images which before and after applying motion correction, and the signal of frequency was analysed after frequency spatial domain was transformed into 2D FFT. Supplementary examination, the blind test was performed by the nuclear medicine department staff. Results: First, the resolution in the static image and summed dynamic image without motion were 8.32 mm, 8.37 mm on X-axis and 8.30 mm, 8.42 mm on Y-axis, respectively. The counts were 484 kcounts, 485 kcounts each, so there was nearly no difference. Secondly, the resolution in the image with minimal motion applying motion correction was 8.66 mm on X-axis, 8.85 mm on Y-axis and had 469 kcounts while the image without motion correction was 21.81 mm, 24.02 mm and 469 kcounts in order. So, this shows the image with minimal motion applying motion correction has similar resolution with the static image. Lastly, the resolution in the images with excessive motion applying motion correction were 9.09 mm on X-axis, 8.83 mm on Y-axis and had 469 kcounts while the image without motion correction was 47.35 mm, 40.46 mm and 255 kcounts in order. Although there was difference in counts because of deletion of blurred frames, we could get similar resolution. And when the image was transformed into frequency, the high frequency was decreased by the movement. However, the frequency was improved again after motion correction. In the blind test, there was no difference between the image applying motion correction and the static image without motion. Conclusion: There was no significant difference between the static image and the summed dynamic image. This technique can be applied to patients who may have difficulty remaining still during the imaging process, so that the quality of image can be improved as well as the reliance for analysis of quantity. Moreover, the re-examination rate will be considerably decreased. However, there is a limit of motion correction, more time will be required to successfully image the patients applying motion correction. Also, the decrease of total counts due to deletion of the severe blurred images should be calculated and the proper number of frames should be acquired.

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Identification and Assessment of Paradoxical Ventricular Wall Motion Using ECG Gated Blood Pool Scan - Comparison of Cine Loop, Phase Analysis and Paradox Image - (ECG Gated Blood Pool Scan을 이용한 심실벽 역행성 운동의 평가 - Cine Loop, Phase Analysis, Paradox Image의 비교 -)

  • Lee, Jae-Tae;Kim, Gwang-Weon;Jeong, Byeong-Cheon;Lee, Kyu-Bo;Whang, Kee-Suk;Chae, Sung-Chul;Jeon, Jae-Eun;Park, Wee-Hyun;Lee, Hyong-Woo;Chung, Jin-Hong
    • The Korean Journal of Nuclear Medicine
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    • v.24 no.2
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    • pp.244-253
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    • 1990
  • Sixty-four patients with paradoxical ventricular wall motion noticed both in angiocardiography or 2-dimensional echocardiography were assessed by ECG gated blood pool scan (GBPS). Endless cine loop image, phase and amplitude images and paradox image obtained by visual inspection of each cardiac beat or Fourier transformation of acquired raw data were investigated to determine the incremental value of GBPS with these processing methods for identification of paradoxical ventricular wall motion. The results were as follows: 1) Paradoxical wall motions were observed on interventricular septum in 34 cases, left ventricular free wall in 26 and right ventricular wall in 24. Underlying heart diseases were ischemic (23 cases) valvular(9), congenital heart disease (12), cardiomyopathy (5). pericardial effusion(5), post cardiac surgery(3), col pulmonale (2), endocarditis(1) and right ventricular tumor(1). 2) Left ventricular ejection fractions of patients with paradoxical left ventricular wall motion were significantly lower than those with paradoxical septal motion(p<0.005). 3) The sensitivity of each processing methods for detecting paradoxical wall motion was 76.9% by phase analysis, 74.6% by endless cine loop mapping and 68.4% by paradox image manipultion respectively. Paradoxial motions visualized only in phase, paradox or both images were appeared as hypokinesia or akinesia in cine loop image. 4) All events could be identified by at least one of above three processing methods, however only 34 cases (48.4%) showed the paradoxical molies in all of the three images. By these findings, we concluded that simultaneous inspection of all above three processing methods-endless cine loop, phase analysis and paradox image-is necessary for accurate identification and assessment of paradoxical ventricular wall motion when performing GBPS.

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Development of Integration Protocol of Nuclear Medicine Image with A Commercial PACS (핵의학 영상을 상용 PACS에 연동 전송하는 프로토콜 개발)

  • Im, Ki-Chun;Choi, Yong;Park, Jang-Chun;Song, Tae-Yong;Choi, Yeon-Sung;Lee, Kyung-Han;Kim, Sang-Eun;Kim, Byung-Tae
    • Journal of Biomedical Engineering Research
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    • v.23 no.6
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    • pp.431-436
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    • 2002
  • The purpose of this study was to develop an integration protocol of Nuclear Medicine image with a commercial PACS. Two independent local networks. PACS network and Nuclear Medicine network, were connected using a Nuclear Medicine DICOM gateway A DICOM converter Program was developed to convert Interfile 3.3. which is used in nuclear medicine scanners in our hospital. to DICOM 3.0. The Program converts Interfile format images to those of DICOM format and also transfers converted DICOM files to PACS DICOM gateway. PACS DICOM gateway compares and matches the DICOM image information with patient information in Hospital Information System and then saves to PACS database. The transfer protocol was designed to be able to transfer Interfile. screen dumped file. and also scanned file. We successfully transferred Nuclear Medicine images to PACS. Images transferred by Interfile transfer protocol could be further processed using various tools in PACS. The graphs, numerical information and comments could be conveniently transferred by screen dumped file. The image in a hard copy can be transferred after scanning using an ordinary scanner. The developed protocol can easily transfer Nuclear Medicine images to PACS in various forms with low cost.