• 한국의학물리학회지:의학물리
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• 제19권3호
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• pp.178-185
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• 2008

간경변 및간암 환자의 증가로 간이식술의 필요성이 점점 증가되고 있고, 특히 공여자의 생체 간이식은 간이식술의 주된 분야를 차지하고 있으며 간이식 수술 전 공여자에서 간체적의 정확한 측정은 수술 후 공여자와 수여자의 간기능을 예측하는데 있어 중요한 자료가 되며, 성공적인 수술과 환자의 예후에 밀접한 영향을 미친다. 그러나 현재 환자의 간체적을 구하는 과정은 환자의 모든 CT 영상위의 간을 수작업을 통해 영상분할한 후에 3차원 간체적을 구하고 있으며 많은 시간과 노력이 필요한 작업이다. 이러한 문제를 해결하기 위해서 본 논문에서는 자동으로 간과 비장을 문턱값처리, 형태학적 영상처리, 3차원 영역확장법등의 기법을 이용하여 분할하는 알고리즘을 개발하여 체적을 구하는 시간을 단축하였다. 이러한 알고리즘의 정확성을 평가하기 위해서 동물의 실제 간과 비장을 팬텀으로 제작하여 실제 측정한 체적과 알고리즘으로 분할된 영상의 결과를 비교 평가하였다. 문턱치값의 설정에 따라 다른 결과를 보이는 특성이 있지만 자동으로 문턱치를 결정했을 때 비장과 간의 체적측정 오차는 9.27%, -4.52%이었으며, 수동으로 문턱치를 결정했을 때 최소 오차가 각각 0.2%, 0.17%의 결과를 보였다. 이러한 팬텀 연구를 통해 자동 분할 알고리즘으로 얻은 체적의 결과가 정확성과 재현성을 보여주어 추후 간체적을 구하는 보조수단으로 활용될 수 있을 것이라 예상된다.

• Investigative Magnetic Resonance Imaging
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• 제12권2호
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• pp.100-106
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• 2008

본 연구는 in vivo 보다 더욱 정확하게 뇌 대사물질을 정량 분석하고자 고자장 NMR 장비 (500MHz; 11.74T)를 이용하여 동물의 뇌를 in vitro 환경에서 조사 및 분석하였다. 일반적으로 in vivo 실험은 생체 내부의 혈류나 조직의 비균질성으로 인한 자기공명분광법의 shimming에 악영향을 미치기 때문에 부정확한 결과를 산출할 수 있다. 그러나, in vitro 실험은 이에 비하여 균질한 샘플을 사용하고 보다 고자장에서 실험환경을 조성할 수 있기 때문에 더욱 정확한 대사물질의 정보를 얻을 수 있다. 본 연구에서는 개 (canine)의 소뇌 (cerebellum)조직으로부터 대사물질을 추출하고 고자장 핵자기공명분광법으로 대사물질의 절대농도를 획득 하고자 하였다. 생체 대사물질의 절대농도를 획득하기 위하여 대표적인 대사물질(i.e., NAA, Cr, Cho, Ins, Lac, GABA, Glu, Gln, Tau Ala)의 팬톰을 제작하여 그 스펙트럼을 확보하였고, 개의 소뇌 부위를 적출하여 methanol-chloroform water extraction (M/C water extraction) 방법으로 대사물질만을 추출한 후 자기공명분광법을 수행하였다. 필터링 (filtering)의 효과를 평가하기 위하여 샘플 제작 시 추출물을 필터링한 그룹과 필터링하지 않은 그룹으로 분류하여 실험을 수행하였다. 팬텀 물질과 추출물은 90% D2O 수용액으로 만든 후 5mm NMR 튜브에 담아 실험하였다. 실험 결과 조직 추출물을 필터링하는 것이 신호대잡음비(signal to noise ratio: SNR, S/N)를 향상시키는 데 기여하는 것을 확인하였다. 또한 개의 소뇌 대사물질의 절대농도는 사람보다는 쥐 (rat)의 뇌 대사물질 절대농도와 더 비슷한 것을 확인할 수 있었다. 본 연구 결과를 토대로 고자장 핵자기공명분광법을 이용한 in vitro 실험은 뇌조직 내 대사물질의 절대농도를 측정하고 기본적인 지표를 확보하는데 매우 정확하고 정량적인 방법이 될 수 있을 것으로 사료된다.

• 한국방사선학회논문지
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• 제4권1호
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• pp.25-30
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• 2010

이 연구 목적은 흉부영상의 진단에 적절한 해상력과 음영에 대한 적절한 평가를 위해서다. 해상력을 비교하기 위해서, linear 해상력 팬텀을 사용하여 film/screen(선생님이 원하시는 conventional radiography : film/screen), CR, DR, 촬영했다. 해상력을 비교하기 위해 2명의 영상의학과 전문의와 3명의 방사선사가 블라인드 테스트를 통하여 평가했다. DR 은 3.95 필름/ 스크린은 3.58, CR은 3.48의 평가가 나왔다. 음영에 대해 분석은, CR, DR의 film/screen의 정상적인 흉부영상 50장을 선택했다. 이 흉부영상에서 7부위(폐야, 폐야 윤곽, 종격동 I, 종격동 II, 심장 음영 I, 심장음영 II, 횡격막)을 정하여 덴시토미터(농도계)을 사용하여 음영을 평가했다. 우리의 분석 방법은 낮은 영상(음영)을 0에서부터 가장 우수한 영상(음영) 2를 정한 일본의 흉부 x-ray 평가 방법을 적용했다. DR의 경우 종격동 1, 종격동2, 심장 1, 심장2, 횡격막에서 2점을 기록하여 우수했다. 이와 반대로 CR에서는 폐부위와 폐음영 부위에서 2점으로 우수했다. 결론적으로, 해상력과 음영에 비교하면 후처리 알고리즘과 작은 픽셀 사이즈에 의한 DR은 CR과 film/screen 보다 우수하다고 도출하였다.

• Journal of Korean Neurosurgical Society
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• 제29권10호
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• pp.1309-1315
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• 2000

Objectives : We performed an in vivo experiment to investigate the effect of $^{166}Holmium$ and $^{166}Holmium$-chitosan complex($^{166}Ho$-CHICO) on the normal brain of rats and to determine the sublethal dose of $^{166}Ho$-CHICO. Materials and Methods : $^{166}Ho$ is a beta and gamma ray emitter. $^{166}Ho$-CHICO is a novel radio-pharmaceutical complex with chitosan to facilitate the transport of $^{166}Ho$ obtained from Korea Atomic Energy Research Center(Taejon, Korea). It is in acidic form and becomes gel state at alkaline pH. One hundred and seventy consecutive rats were divided into four groups : $^{166}Ho$ treated(n＝50), $^{166}Ho$-CHICO treated(n＝57), saline treated(n＝5) and chitosan treated(n＝5) groups. $^{166}Ho$ and $^{166}Ho$-CHICO were injected into the rat brain stereotactically with various doses of 0.1mCi/$20{\mu}l$, 0.2mCi/$20{\mu}l$, 0.3mCi/$20{\mu}l$, and 0.4mCi/$20{\mu}l$ using an automated microinjector. Nuclear imaging, histopathological and hematological studies were performed in 10 rats in each group at 1 day, 3days, 7 days, 1 month and 3 months after the injections. Results : An infiltration of inflammatory cells and necrotic changes were noted in $^{166}Ho$ treated group at 1 week after the injection. A wedge-shaped tissue defect due to necrosis, lined with infiltrated glial cells in $^{166}Ho$ treated group and a cystic defect lined with reactive astroglial cells in $^{166}Holmium$-CHICO treated group at 3 months after the injection were observed. $^{166}Ho$ alone without chitosan leaked out and caused necrotic lesion on the cerebral surface but $^{166}Holmium$-CHICO treated group did not show this feature. As the dose of $^{166}Ho$ increased, the mortality rates were also increased. The mortality rate of the $^{166}Holmium$-CHICO group was higher than the $^{166}Ho$ treated group at a dose of 0.4mCi/$20{\mu}l$/300g. There was no detectable radioactivity due to the leakage or extravasation from the injected site of the brain on the scintigraphy performed at 1 hour, 24 hours and 48 hours after the injection. There was also no detectable activity of $^{166}Holmium$-CHICO in other organs including spleen, liver and kidney. Conclusions : $^{166}Ho$-CHICO did not leak out to the critical cortical surface of the brain from the injection site and induced radiation changes of the parenchyma around the injection site without cortical damage. The sublethal dose of $^{166}Ho$-CHICO for the normal brain in rats was determined to be 0.2mCi/$20{\mu}l$/300g.

• 대한방사선기술학회지:방사선기술과학
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• 제41권5호
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• pp.487-491
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• 2018

The purpose of this study was to analyze questionnaires of 161 college students attending radiology departments in order to investigate the actual condition of internet use of radiology students. As a result, 95% of college students using the Internet showed 5.8% of general knowledge, 56.9% of radiation major, and 45.8% of general education. In the field of Internet use, basic medicine was 71.2%, anatomy 59.5% and physiology 51.6%. Radiation theory was 39.9% in radiation physics, 31.4% in radiation biology, and 18.3% in radiation management. The radiological applications were followed by radiography and radiography in order of 31.4% and 20.3%, respectively. The radiological imaging was 45.8%, MRI was 37.9%, CT was 37.3%, ultrasound was 24.2%, And radiation nuclear medicine 25.5%. The results of the descriptive statistics of the satisfaction of the contents using the Internet media showed that the overall satisfaction was below 2.5 Based on the results of this study, it is necessary to develop a program with high accessibility to provide various opportunities for internet-based opportunities to increase the academic achievement value of major subjects through the internet and to solve the difficulties in the major subject.

• Asian Pacific Journal of Cancer Prevention
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• 제17권7호
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• pp.3161-3166
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• 2016

Background: Metastatic renal cell carcinoma (mRCC) status as poor prognosis improved with the introduction of tyrosine-kinase inhibitors, especially sunitinib. There is sparse data reporting from our region on use of sunitinib in metastatic RCC. Thus the present study explores sunitinib usage at our institute. Materials and Methods: An unselected population of patients with metastatic RCC receiving sunitinib was analyzed with respect to patient characteristics, response, toxicity, and outcomes. Results: Fourty-nine patients with a median age of 50.5 years (range 21-71 years) were included. Most were male (61.2%). Twenty‑one (42.9%) had metastatic disease at presentation. Sunitinib was first line therapy in 45. Conventional clear cell carcinoma was the most common pathology present (39 patients; 79.59 %). The most common site of metastasis was the lung (75.5%). Most patients (30) were started at a dose of 50 mg once a day for 4 weeks and then 2 weeks rest. Clinical benefit rate was 73.5% (n= 36), and 22.5% (n= 11) demonstrated progressive disease at first imaging evaluation within the first 3-6 months. The following objective response performed for patients was 48.9% (n=24) and progression at 24.5 % (n=12). The median follow‑up was 16 months (range, 4-34 months), the overall estimated median PFS was 9 months and the estimated median OS was 15 months. Conclusions: This study demonstrated sunitinib is tolerable and effective in advanced/metastatic RCC Egyptian patients and indicates we should further seek second and third lines to increase survival equivalence as reported in the worldwide literature.

• 한국의학물리학회지:의학물리
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• 제29권4호
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• pp.123-136
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• 2018

The complex dose distribution and dose transfer characteristics of intensity-modulated radiotherapy increase the importance of precise beam data measurement and review in the acceptance inspection and preparation stages. In this study, we propose a process map for the introduction and installation of high-precision radiotherapy devices and present items and guidelines for risk management at the acceptance test procedure (ATP) and commissioning stages. Based on the ATP of the Varian and Elekta linear accelerators, the ATP items were checked step by step and compared with the quality assurance (QA) test items of the AAPM TG-142 described for the medical accelerator QA. Based on the commissioning procedure, dose quality control protocol, and mechanical quality control protocol presented at international conferences, step-by-step check items and commissioning guidelines were derived. The risk management items at each stage were (1) 21 ionization chamber performance test items and 9 electrometer, cable, and connector inspection items related to the dosimetry system; (2) 34 mechanical and dose-checking items during ATP, 22 multileaf collimator (MLC) items, and 36 imaging system items; and (3) 28 items in the measurement preparation stage and 32 items in the measurement stage after commissioning. Because the items presented in these guidelines are limited in terms of special treatment, items and practitioners can be modified to reflect the clinical needs of the institution. During the system installation, it is recommended that at least two clinically qualified medical physicists (CQMP) perform a double check in compliance with the two-person rule. We expect that this result will be useful as a radiation safety management tool that can prevent radiation accidents at each stage during the introduction of radiotherapy and the system installation process.

• Advances in nano research
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• 제10권5호
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• pp.461-470
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• 2021

Infection is one of the major mortality causes throughout the globe. Nuclear medicine plays an important role in diagnosis of deep infections such as osteomyelitis, arthritis infection, heart valve and heart prosthesis infections. Techniques such as labeled leukocytes are sensitive and selective for tracking the inflammations but they are not suitable for differentiating infection from inflammation. Anionic linear-globular dendrimer-G₂ was synthesized then conjugation to gemifloxacin antibiotic. The structures were identified by FT-IR, ¹H-NMR, C-NMR, LC-MS and DLS. The toxicity of gemifloxacin and dendrimer-gemifloxacin complex was compared by MTT test. Dendrimer-G₂-gemifloxacin was labeled by Technetium-99m and its in-vitro stability and radiochemical purity were investigated. In-vivo biodistribution and SPECT imaging were studied in a rabbit model. Identify and verify the structure of the each object was confirmed by FT-IR, ¹H-NMR, C-NMR and LC-MS, also, the size and charge of this compound were 128 nm and -3/68 mv respectively. MTT test showed less toxicity of the dendrimer-G₂-gemifloxacin than free gemifluxacin (P < 0.001). Radiochemical yield was > %98. Human serum stability was 84% up to 24 h. Biodistribution study at 50 min, 24 and 48 h showed that the complex is significantly absorbed by the intestine and accumulation in the lungs and affects them, finally excreted through the kidneys, biodistribution results are consistent with results from full image means of SPECT/CT technique.

• 대한방사성의약품학회지
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• 제9권1호
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• pp.3-8
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• 2023

Parkinson's disease is a neurodegenerative disease caused by damage to brain neurons related to dopamine. Non-clinical animal models mainly used in Parkinson's disease research include drug-induced models of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and 6-hydroxydopamine, and genetically modified transgenic animal models. Parkinson's diagnosis can be made using brain imaging of the substantia nigra-striatal dopamine system and using a radiotracer that specifically binds to the dopamine transporter. In this study, ¹⁸F-N-(3-fluoropropyl)-2β-carboxymethoxy-3β-(4-iodophenyl) nortropane was used to confirm the image evaluation cutoff between normal and parkinson's disease models, and to confirm model persistence over time. In addition, the efficacy of single or combined administration of clinically used therapeutic drugs in parkinson's animal models was evaluated. Image analysis was performed using the PMOD software. Converted to standardized uptake value, and analyzed by standardized uptake value ratio by dividing the average value of left striatum by the average value of right striatum obtained by applying positron emission tomography images to the atlas magnetic resonance template. The image cutoff of the normal and the parkinson's disease model was calculated as SUVR=0.829, and it was confirmed that it was maintained during the test period. In the three-drug combination administration group, the right and left striatum showed a high symmetry of more than 0.942 on average and recovered significantly. Images using ¹⁸F-N-(3-fluoropropyl)-2β-carboxymethoxy-3β-(4-iodophenyl) nortropane are thought to be able to diagnose and evaluate treatment efficacy of non-clinical Parkinson's disease.

• 대한방사성의약품학회지
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• 제6권2호
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• pp.61-68
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• 2020

Aggregated neurofibrillary tangles (NFTs) are a pathological hallmark in Alzheimer's disease (AD) and many radiopharmaceuticals targeting NFTs have been developed so far. Among these, [¹⁸F]flortaucipir (TAUVID^TM) is the first approved radiopharmaceutical in the Food and Drug Administration (FDA) to image tau pathology. In the present study, we describe the optimized radiosynthetic method for the routine production of [¹⁸F] flortaucipir using a commercialized automation module (i.e. GE TRACERlab^TM FX_FN pro). [¹⁸F]Flortaucipir was prepared by nucleophilic substitution from its N-tert-butoxycarbonyl protected nitro precursor, tertbutyl 7-(6-nitropyridin-3-yl)-5H-pyrido[4,3-b]indole-5-carboxylate, at 130℃ for 10 min in dimethyl sulfoxide. The mean radiochemical yield was 20 ± 4.3% (decay-corrected, n = 47) with the molar activity of 218 ± 32 GBq/µmol at the end of synthesis. The radiochemical purity was determined to be above 95%. The overall production time including quality control is approximately 100min. The final produced [¹⁸F]flortaucipir injection meets the USP criteria for quality control. Thus, this fully automated system is validated for clinical use.