• 한국환경농학회지
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• 제18권1호
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• pp.41-47
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• 1999

NaCl과 방사선이 자주달개비 수술털 세포 분홍돌연변이에 미치는 영향을 조사하였다. 포트에서 생육된 Tradescantia 4430 식물체에 코발트 선원으로부터 0.3, 0.5, 1.0 및 2.0Gy의 감마선을 조사하였다. NaCl 용액(170mM)의 분무처리는 방사선 조사 24시간전 및 후에 이루어졌다. CT 실험군, NaCl+${\gamma}$실험군 및 ${\gamma}$+NaCl 실험군에 있어서의 돌연변이 빈도가 증가한 고조기간은 방사선 조사 후 6∼12일로 나타났으며 돌연변이 빈도는 방사선량 증가에 따라 선형적으로 증가하는 반응관계를 보였다. CT 실험군에서의 선량반응식 기울기(증가계수)는 5.99($r^2$=0.99)이었으나, NaCl+${\gamma}$실험군의 증가계수는 4.55($r^2$=0.98), ${\gamma}$+NaCl 실험군은 4.33($r^2$=0.99)으로 CT실험군의 값에 비해 낮았다. 즉, 방사선 조사 전후에 NaCl을 처리한 실험군들이 방사선만 조사한 CT 조사군에 비하여 방사선에 의한 돌연변이 유발증가율이 24% 이상 억제됨을 확인할 수 있었으며 이는 NaCl 자체가 방사선에 의한 DNA 손상에 대하여 방어효과를 갖기 때문인 것으로 해석될 수 있다.

• 대한디지털의료영상학회논문지
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• 제12권2호
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• pp.113-117
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• 2010

This research attempts to qualitatively evaluate the intensity change by radiopharmaceuticals and obtain computed tomography using phantom injected with various nuclide. Cylindrical phantom is used for comparing and analysing the effect on diagnosis image during radiopharmaceuticals inspection. Inside of the phantom, water is injected and computed tomography image is scanned. During nuclear medicine invitro, frequently used radiopharmaceuticals, $^{99m}TcO_4$ 20 mCi and $^{18}F$ 14 mCi, is diluted in the water phantom and scanned in the same method. Traverse image obtained by CT scan is divided into six traverse image in the same slice of each scanned image. CT-number(HU) value of 10 measuring point is measured in 2 cm interval based on the center of the phantom. Measured HU value, based on the water phantom, is compared with the image after injecting $^{99m}TcO_4$ and $^{18}F$. Average scale of water is 2.8~1.6 HU, $^{99m}TcO_4$ is 3.0~1.6 HU and $^{18}F$ is 1.2~0 HU. Average of water is $2.3{\pm}0.17$ HU, $^{99m}TcO_4$ is $2.2{\pm}0.85$ HU and F-18 is $0.7{\pm}0.95$ HU. Based on water, reduced value of about 0.1 HU and about 0.5 HU is acquired from $^{99m}TcO_4$ and F-18. Radionuclide used in nuclear medicine inspection utilizes 100~200 KeV energy and obtains image through scintillation camera and PET-CT utilizes 511 KeV positron annihilation energy to obtain image. What we learned from this research is that gamma rays from these energies used in CT scan for diagnosis purpose or radioactive therapy plan can change the intensity of the image. The nuclear medicine inspection for reducing the effect of emitted gamma ray diagnosis image should be obtained after a period of time considering half-life which would be reduced distortion or changed in image.

• 대한핵의학회지
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• 제38권5호
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• pp.344-346
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• 2004

A 69-year-old woman was presented with progressed dysphagia, gastric soreness and weight loss during 2 months. She was performed abdomen x-ray, EGDS and abdomen CT. Abdomen x-ray demonstrated punctuate calcification on LUQ. EGDS showed an ulceroinfiltrative mass with bleeding on cardia to antrum of stomach. And CT showed diffuse gastric wall thickness with multiple calcifications. Biopsy of the stomach and esophagus during EGDS examination revealed an adenocarcinoma, with signet ring cell type, infiltrating the wall of the stomach and the distal esophagus. Then acne scan was performed a few days later. It revealed intense uptake in LUQ, corresponding to the calcium containing neoplasm seen on the abdomen x-ray, EGDS and abdomen CT. And there was no evidence of any metastatic lesion and thyroid uptake on the bone scan. There are many reports about accumulation of the tracer in extraosseous lesion, but only a few literatures were reported about gastric calcification in stomach cancer. More over, no reports showed CT images. We are performed many diagnostic examinations and found well correlation between them. The reason of gastric calcification is considered with calcium deposition within extracellular space due to hemorrhage or necrosis. Other possibility offered to explain gastric calcification have been increased blood flow and/or increased neovascularity with capillary leaks of tracer, and specific enzymatic (phosphatases) receptor binding of tracer. So, it was happened ion exchange between intracellular calcium and phosphate groups of tracer.

• Imaging Science in Dentistry
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• 제49권1호
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• pp.53-58
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• 2019

Purpose: To present characteristic findings of Tc-99m hydroxymethylene diphosphonate (HMDP) scintigraphy, computed tomography (CT), and magnetic resonance (MR) imaging for osteonecrosis in the mandible, especially osteoradionecrosis(ORN) and medication-related osteonecrosis of the jaw(MRONJ). Materials and Methods: Thirteen patients with MRONJ and 7 patients with ORN in the mandible underwent Tc-99m HMDP scintigraphy, CT, and MR imaging (T1-weighted images[T1WI], T2-weighted images[T2WI], short inversion time inversion recovery images[STIR]), diffusion-weighted images[DWI], and apparent diffusion coefficient [ADC] mapping). The associations of scintigraphy, CT, and MR imaging findings with MRONJ and ORN were analyzed using the chi-square test with the Pearson exact test. Results: Thirteen patients with MRONJ and 7 patients with ORN in the mandible showed low signal intensity on T1WI and ADC mapping, high signal intensity on STIR and DWI, and increased uptake on scintigraphy. Periosteal bone proliferation on CT was observed in 69.2% of patients with MRONJ(9 of 13) versus 14.3% of patients with ORN(1 of 7)(P=0.019). Conclusion: This study presented characteristic imaging findings of MRONJ and ORN on scintigraphy, CT, and MR imaging. Our results suggest that CT can be effective for detecting MRONJ and ORN.

• 환경생물
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• 제39권3호
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• pp.336-343
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• 2021

Fumigation of fruits and vegetables during quarantine and pre-shipment(QPS) treatment should be effective with a shorter fumigation time to minimize phytotoxicity. In this research study, a shorter fumigation time, 2 hours exposure which is shorter than that of the current commercial fumigation procedures using a lower dose of ethyl formate (EF) mixed with phosphine (PH₃) on strawberry was investigated. The reciprocal effect between EF and PH₃ against nymphs and adult Myzus persicae (Sulzer) and Tetranychus urticae (Koch) was evaluated. In addition, L(Ct)₅₀ and L(Ct)₉₉ of EF only and EF mixed with PH₃ were analyzed at 5℃ and 20℃. The synergistic ratio (SR) of L(Ct)₅₀ and L(Ct)₉₉ for the nymph and adult stages of M. persicae were >1.0, which indicated a synergistic effect between EF and PH₃. However, the SR values of L(Ct)₅₀ and L(Ct)₉₉ of the nymph and adult stages of T. urticae were ≤1.0 indicating that there was no synergistic effect between the two fumigants against T. urticae. Our results showed that the reciprocal effect between EF and PH₃ has different effects on M. persicae and T. urticae. This could be attributed to the biological and physical differences between the class Arachnida and Insecta. The synergistic effect between EF and PH₃ against M. persicae within a shorter exposure period and without phytotoxicity on fruits and vegetables will significantly benefit the horticultural industry.

• Korean Journal of Radiology
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• 제25권3호
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• pp.257-266
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• 2024

Objective: To investigate molecular and functional consequences of additional exposures to iodine- or gadolinium-based contrast agents within 24 hours from the initial intravenous administration of iodine-based contrast agents through an animal study. Materials and Methods: Fifty-six Sprague-Dawley male rats were equally divided into eight groups: negative control, positive control (PC) with single-dose administration of CT contrast agent, and additional administration of either CT or MR contrast agents 2, 4, or 24 hours from initial CT contrast agent injection. A 12 µL/g of iodinated contrast agent or a 0.47 µL/g of gadolinium-based contrast agent were injected into the tail vein. Serum levels of blood urea nitrogen, creatinine, cystatin C (Cys C), and malondialdehyde (MDA) were measured. mRNA and protein levels of kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) were evaluated. Results: Levels of serum creatinine (SCr) were significantly higher in repeated CT contrast agent injection groups than in PC (0.21 ± 0.02 mg/dL for PC; 0.40 ± 0.02, 0.34 ± 0.03, and 0.41 ± 0.10 mg/dL for 2-, 4-, and 24-hour interval groups, respectively; P < 0.001). There was no significant difference in the average Cys C and MDA levels between PC and repeated CT contrast agent injection groups (Cys C, P = 0.256-0.362; MDA, P > 0.99). Additional doses of MR contrast agent did not make significant changes compared to PC in SCr (P > 0.99), Cys C (P = 0.262), and MDA (P = 0.139-0.771) levels. mRNA and protein levels of KIM-1 and NGAL were not significantly different among additional CT or MR contrast agent groups (P > 0.05). Conclusion: A sufficient time interval, probably more than 24 hours, between repeated contrast-enhanced CT examinations may be necessary to avoid deterioration in renal function. However, conducting contrast-enhanced MRI on the same day as contrast-enhanced CT may not induce clinically significant kidney injury.

• Nuclear Medicine and Molecular Imaging
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• 제43권1호
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• pp.87-89
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• 2009

• 핵의학기술
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• 제26권2호
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• pp.20-31
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• 2022

Broad Quantification Calibration(B.Q.C)은 SPECT/CT 장비에서 정량적인 평가(Quantitative Analysis)에 사용되는 표준 섭취 계수(Standard Uptake Value; SUV) 측정을 위한 Calibration 이다. Tc-99m, I-123, I-131, Lu-177 네 가지 핵종 별로 B.Q.C 를 시행한 후 SUV 가 정확하게 측정되는지를 검증하기 위해 팬텀 실험을 추가로 시행하였다. SPECT 장비를 위한 국제 기준이 아직까지 명확하게 마련되지 있지 않아 ACR Esser PET phantom을 이용하여 감마카메라 장비에서 사용하는 핵종 별로 SUV 측정을 위한 기반 작업을 수행하고자 하였다. 실험에 사용 된 SPECT/CT 장비는 SIEMENS 사의 Symbia Intevo 16과 Symbia Intevo Bold 두 장비이다. B.Q.C는 point source 를 이용하여 각 detector 에 감도를 인식시켜주는 sensitivity cal. 을 1 차로 시행하고, cylinder phantom 을 이용하여 Volume Sensitivity Factor(VSF)를 산출하는 volume sensitivity cal.을 추가로 시행한다. SUV 측정을 위해 ACR Esser PET phantom을 이용하여 Tc-99m, I-123, I-131, Lu-177 네 가지 핵종 별로 팬텀 영상을 획득하고, 배후방사능(BKG)의 SUV_mean와 네 개의 hot vial(25, 16, 12, 8 mm)에서의 SUV_max를 측정하였다. Intevo 16, Intevo Bold 두 장비간의 SUV 차이를 비교하기 위해 SPSS ver. 21(IBM company, USA)을 이용하여 Mann-Whitney 검정을 시행하였다. B.Q.C 시행에 따른 네 가지 핵종 별로, 각 장비와 Detector 1, 2 에서의 Sensitivity(CPS/MBq) 및 VSF 는 다음과 같다(Intevo 16 D1 sensitivity/D2 sensitivity/VSF, Intevo Bold 순). Tc-99m 에서는 87.7/88.6/1.08, 91.9/91.2/1.07, I-123에서는 79.9/81.9/0.98, 89.4/89.4/0.98, I-131에서는 124.8/128.9/0.69, 130.9, 126.8/0.71, Lu-177 에서는 8.7/8.9/1.02, 9.1/8.9/1.00 이었다. ACR Esser PET 팬텀 실험에서 SUV 결과는 다음과 같다(Intevo 16 BKG SUV_mean/25mmSUV_max/16mm/12mm/ 8mm, IntevoBold순). Tc-99m에서는 1.03/2.95/2.41/1.96/1.84, 1.03/2.91/2.38/1.87/1.82, I-123에서는 0.97/2.91/2.33/ 1.68/1.45, 1.00/2.80/2.23/1.57/1.32, I-131에서는 0.96/1.61/ 1.13/1.02/0.69, 0.94/1.54/1.08/0.98/0.66, Lu-177에서는 1.00/ 6.34/4.67/2.96/2.28, 1.01/6.21/4.49/2.86/2.21 이었다. 두 장비 간의 팬텀 실험 별 SUV 차이를 비교하기 위해 MannWhitney 검정을 시행한 결과, 통계적으로 유의한 차이가 없었다(z=-0.338, p=0.735). 기존 감마카메라는 단면 영상의 육안적인 평가만 가능하였다면, SPECT/CT 영상을 통해 해부학적 정보와 3차원 단층 영상 획득 및 SUV 측정으로 정량 분석이 가능하게 되었다. 주로 사용하는 Tc-99m 뿐만 아니라 I-123, I-131, Lu-177 핵종에 대해서도 Broad Quantification Calibration 을 시행하여 핵종 별로 정량적인 정보를 획득 할 수 있는 기반 작업이 수행 되었고, ACR Esser PET phantom 실험을 통해 SUV 측정의 신뢰도에 대한 검증도 수행 되었다. 장비의 성능 및 정량분석의 재현성을 유지하기 위해 주기적인 장비의 정도관리가 필요할 것이며, 이를 통해 Bone SPECT/CT 뿐만 아니라 기타 다른 SPECT/CT 영상 검사의 추적관찰 및 동위원소 치료 분야에서도 치료반응을 평가하는 등의 많은 도움이 될 것으로 사료된다.

• Journal of Magnetics
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• 제19권3호
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• pp.248-254
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• 2014

The purpose of this study is to figure out how uptake counts of technetium ($^{99m}Tc$) among radioisotopes in the human body are affected if computed tomography (CT), magnetic resonance imaging (MRI) and isotope examination are performed consecutively. $^{99m}Tc$ isotope material, iodinated contrast media for CT and paramagnetic contrast media for magnetic resonance (MR) were used as experimental materials. First, $^{99m}Tc$ was added to 4 cc normal saline in a test tube. Then, 2 cc of CT contrast media such as $Iopamidol^{(R)}$ and $Dotarem^{(R)}$ were diluted with 2 cc normal saline, and 2cc of MRI contrast media such as $Primovist^{(R)}$ and $Gadovist^{(R)}$ were diluted with 2 cc normal saline. Each distributed contrast media was a total of 4 cc and included 10m Ci of $^{99m}Tc$. A gamma camera, a LEHR (Low energy high resolution) collimator and a pin-hole collimator were used for image acquisition. Image acquisition was repeated a total of 6 times and 120 frames were obtained and uptake counts of $^{99m}Tc$ were measured (from this procedure). In this study, as a result of measuring the uptake counts of $^{99m}Tc$ using the LEHR collimator, the uptake counts were less measured in all contrast media than normal saline as a reference. In particular, the lowest uptake counts were measured when $Gadovist^{(R)}$, contrast media for MRI, was used. However, the result of measuring the uptake counts of $^{99m}Tc$ using the pin-hole collimator showed higher uptake counts in all contrast media, except for $Iopamidol^{(R)}$, than normal saline as a reference. The highest uptake counts were measured particularly when $Primovist^{(R)}$, contrast media for MRI, was used. In performing the gamma camera examination using contrast media and $^{99m}Tc$, it is considered significant to check the changes in the uptake counts to improve various diagnosis values.

• 핵의학기술
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• 제17권2호
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• pp.53-58
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• 2013

본 연구에서는 각기 다른 에너지의 방사성동위원소를 이용하여 CT를 기초로 한 attenuation correction (AC)과 scatter correction (SC)을 적용했을 때 영상의 질을 비교분석하고 영상보정기법의 유용성에 대해 알아보고자 하였다. Resolution 평가를 위해 사용된 spatial resolution phantom 내부에 물을 채우고 각각의 동위원소 $^{99m}Tc$ (140 keV, 2.22 kBq), $^{201}Tl$ (70 keV, 2.22 kBq), $^{131}I$ (364 keV, 2.22 kBq)을 line에 주입하여 제작하였다. Contrast 평가를 위해 이용한 Jaszczak phantom은 배후방사능과 열소원통의 비율이 1:8이 되도록 각각의 동위원소를 주입하여 제작하였다. GE Infinia Hawkeye4 SPECT/CT (GE Medical System, USA)로 영상을 획득하고, non-correction (NC), AC, SC, AC와 SC가 동시에 적용된(ACSC) 4가지 조건으로 OSEM (2 iterations, 10 subsets)을 이용하여 영상을 각각 재구성하였다. FWHM값은 paired samples t-test를 통하여 유의수준 관계를 분석하였고, percent contrast (%)값은 MATLAB (Ver.7.0)$^{(R)}$과 MRIcro$^{(R)}$를 이용하여 각각의 수치를 비교하였다. $^{99m}Tc$의 resolution test에서 NC, AC, SC, ACSC를 각각 적용했 을 때 FWHM (mm)값은 각각 $4.97{\pm}0.46$, $4.73{\pm}0.27$, $49.7{\pm}0.39$, $4.60{\pm}0.26$, $^{201}Tl$에서는 $5.26{\pm}0.28$, $5.14{\pm}0.21$, $5.25{\pm}0.25$, $5.05{\pm}0.23$, $^{131}I$에서는 $6.24{\pm}0.73$, $5.84{\pm}0.57$, $6.24{\pm}0.69$, $5.98{\pm}0.52$의 값을 얻을 수 있었다. 각 방사성 동위원소의 결과 값에서 NC와 비교하여 AC, ACSC를 적용했을 때 통계적으로 유의한 차이를 보였고(P<0.05), SC만을 적용했을 때는 유의한 차이가 없음을 보여주었다(P>0.05). Contrast test에서는 percent contrast(%) 를 4개의 원통에 대한 값을 구했고, NC와 비교했을 때 AC, SC, ACSC의 percent difference (%)가 $^{99m}Tc$은 24.73, 38.10, 67.31, $^{201}Tl$은 30.90, 51.82, 86.02, $^{131}I$에서는 18.60, 46.26, 73.67의 차이를 보였다. 본 연구의 결과에 따르면 $^{99m}Tc$, $^{201}Tl$ 과 같은 낮은 에너지를 가진 핵종에 대해서는 ACSC를 동시에 적용한 영상에서 resolution 향상이 가장 크게 나타났지만, $^{131}I$ 같은 높은 에너지의 핵종에서는 AC만 적용되었을 때 ACSC를 적용했을 때보다 영상의 질이 더 향상됨을 알 수 있었다. 그러므로 SPECT/CT 검사 시 사용되는 핵종의 에너지에 따라 적절한 영상보정기법을 적용한다면 정확한 진단을 위한 최적의 영상을 얻을 수 있을 것으로 사료된다.