• 대한핵의학회:학술대회논문집
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• 대한핵의학회 1997년도 제36차 춘계학술대회 초록집
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• pp.150-150
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• 1997

• 대한핵의학회지
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• 제38권2호
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• pp.180-189
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• 2004

다약제내성이 발현된 암세포에서 세포내의 항암제를 세포외로 배출시키는 기전을 체내에서 비침습적인 방법으로 영상화 할 수 있는 SPECT와 PET는 악성종양의 진단과 평가에 중요한 역할을 할 것으로 판단되나, 아직까지도 Pgp와 MRP의 운반능을 적절하게 평가하는 핵의학적 영상방법을 정립하는데는 극복해야할 문제점들이 많다. 지금까지의 MDR영상에 관한 연구들은 대부분이 $^{99m}Tc$-표지 방사성의약품을 이용한 연구였으나, PET의 임상 응용이 증가함에 따라 보다 특이적이고 쉽게 응용될 수 있는 PET용 방사성 추적자의 개발도 이루어져야 할 것이다. $^{99m}Tc$-MIBI의 암 세포내 일방향(unidirectional) 섭취는 음성인 세포막 전하와 세포내 소립체 기질 전하에 의하여 결정되므로, MIBI의 섭취는 다른 지용성 양전하를 띤 막전위 추적자들과 유사하게 작용한다. $^{99m}Tc$-표지 방사성의약품은 암조직의 혈류 증가나 소립체 용적이나 활성도가 증가하면 섭취가 증가할 수 있어 보다 특이적인 MDR추적제의 개발이 필요한 것이다. 최근 Lorke 등은 약제감수성 및 내성 인체대장암세포인 $HT-29^{par}$ 세포와 $HT-29^{mdrl}$ 세포를 이용한 연구에서, 두세포 모두에서 $^{18}F$-FDG의 섭취가 있었고, MDR이 발현된 세포와 종양에서 $^{18}F$-FDG 섭취가 훨씬 낮았고, MIBI는 MDR이 없는 모세포에서도 매우 낮았음을 보고한 바 있다. 이 세포는 전자현미경검사에서 사립체가 풍부하지 않은 세포였다. 그러므로 이러한 결과로 보아 $^{99m}Tc$-MIBI 영상에서 종양이 보이지 않거나 섭취가 미약하다고 해도 MDR이 발현되었다고 단정할 수는 없게 된다. 즉 MDR의 발현유무를 정확하게 감별할 수 있기 위하여는 저항이 없는 세포에 MIBI가 충분하게 섭취되어야 한다는 것이 필수적인 요건이며, 종양세포 종류에 따라서는 FDG가 MDR의 marker가 될 수 있다는 것이다. Pgp 수송체는 ATP의존성 약제배출 펌프이므로 MDR세포는 에너지가 많이 필요하여, MDR 세포는 당분해율(rate of glycolysis)이 증가되어 있고 HT-29 mdrl 종양세포에서는 포도당 이동과정의 변화로 FDG 섭취가 감소되었다. 또한 Pgp가 점차 증가됨과 함께 plasma membrane transporter인 GLUT-1 level이 감소된다. 이러한 결과는 다약제내성의 영상화가 지금까지의 예상보다 보다 복합적이고 다양하므로 보다 많은 연구가 필요할 것이라는 점을 시사한다. 최근 시도되고 있는 생체광학 영상을 이용한 다약제내성 유전자 및 Pgp 발현 연구는 아직 시작단계이나, 분자 생물학적 영상법의 발전과 함께 MRI 기술등에도 이용될 수 있으므로 향후 많은 연구가 있을 것으로 기대된다.

• 대한핵의학회지
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• 제27권2호
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• pp.155-160
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• 1993

심근생존능은 심기능이 저하되어 있으나 적절한 치료에 의해 심기능이 회복될 수 있는 상태를 말하며, 기절심근과 동면심근으로 대변할 수 있다. 기절심근은 심근관류가 정상이지만 아직 심근기능이 회복이 안된 상태로 수 시간 내지 수주일 후에 회복이 되는 상태를 말하며, 동면심근은 심근관류가 오랫동안 감소되어 있어 심기능 저하되어 있지만 심근관류를 정상화시켜주면 바른 시간내에 심기능이 회복되는 상태를 말한다. 임상적으로는 이 두가지 상태가 혼합된 경우도 있으리라 추측되고 있다. 심근생존능을 진단하는 것은 재혈관화 치료를 시행하기 전에 미리 환자의 예후를 결정해 줄 수 있다는 점에서 임상적인 의의가 있다. 그 진단법으로는 PET에 의해 심근대사기능이 존재함을 증명하는 것이 표준으로 되어 있으나, 그 외에도 심장초음파, 심장 MRI등을 이용한 검사법, $^{201}TI$ 또는 $^{99m}Tc-MIBI$를 이용한 신티그라피등의 검사법이 있다. 현재까지 보고된 바를 종합하면 $^{201}TI$ 부하-재분포-재주사영상법이 가장 우수한 것으로 사료되나, 각 진단법이 개선 또는 개발되고 있으므로 이에 대한 계속적인 관심이 필요하며, 핵의학적인 진단방법도 계속적으로 발전시킬 필요가 있다고 사료된다.

• 대한핵의학회지
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• 제28권2호
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• pp.172-176
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• 1994

심근 SPECT에 의한 심근질환의 심도 및 허혈부위를 평가하는 방법으로 정상인의 극성지도와의 비교에 의한 결손지도 평가방법이 상용화되었으나 본 연구에서는 결손부위의 범위만을 산출할 수 있었던 종래의 방법을 개선할 수 있는 관류회복정도 및 심도성적 산출 방법을 시도하여 보았다. 허혈 및 심도성적의 산출에서 부하 및 휴식기 극성지도의 차이를 3등급으로 분할하여 각 등급에 해당되는 화소의 수를 가중하므로서 관류결손부위의 면적이 반영된 허혈 및 심도성적 산출방법을 제안하고자 하였으며, 등급 및 가중치의 할당은 정상인의 잔상동맥영역별 관류분포를 반영하여 고른 등급 할당방법보다 상관도가 개선된 결과를 얻을 수 있었다.

• 대한핵의학회지
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• 제29권4호
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• pp.478-483
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• 1995

We compared the influences of reconstruction methods using $180^{\circ}$ or $360^{\circ}$ data upon contrasts and discriminating capability and diagnostic accuracy in $^{99m}Tc-MIBI$ stress/rest myocardial SPECT. We reviewed SPECT images reconstructed only with $180^{\circ}$ projection data or with $360^{\circ}$ data in 18 patients and in 11 normal subjects. To compare counts of surface structures and deep structures, we measured ape# posterior wall ratios in 11 normal subjects. To compare the contrasts of images, we measured apex/ventricle ratios. To compare contrasts between normal and diseased myocardial segments, we measured count ratios of defect and normal segments in 4 patients who had single coronary artery diseases. To compare diagnostic accuracy, we scored SPECT images made with $180^{\circ}$ and $360^{\circ}$ data segmentally. Sensitivity and specificity for the diagnosis of coronary artery disease and for the revelation of diseased arteries with both $180^{\circ}$ and $360^{\circ}$ SPECT images. If involved coronary arteries had more narrowing than 50% In coronary angiogram, we considered them as diseased arteries Apex/posterior wall ratios were not different significantly in normal subjects. Apex/ ventricle ratios in normal subjects were different significantly between $180^{\circ}$ and $360^{\circ}$ SPECT images. Defect/normal ratios were different significantly between $180^{\circ}$ and $360^{\circ}$ SPECT images in single vessel disease patients. The overall diagnostic accurracy was the same between $180^{\circ}$ and $360^{\circ}$ data collection. Sensitivity was 94% and specificity was 91% for both types of data collection in this sample population. Sensitivity and specificity of each coronary artery territory were not significantly different between the images made with $180^{\circ}$ and $360^{\circ}$ data. The images made with $180^{\circ}$ data had better contrast between ventricle and myocardium and between hypoperfused and normal myocardium, though no difference was found between the ratios of the myocardial counts of surface and deep structures. However, diagnostic sensitivities of diseased artery territories were not different significantly and so were overall diagnostic accuracy between both methods of making images with $180^{\circ}$ and $360^{\circ}$ data.

• 대한핵의학회지
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• 제35권4호
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• pp.213-223
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• 2001

Breast cancer accounts for the higher proportion of cancer related deaths among women, and the incidence of this malignant disease is still increasing. The commonly used screening method is mammography. However, mammography has the drawback of low specificity in differentiating malignant and benign breast diseases. To overcome this low specificity of mammography, scintimammography using various radiopharmaceuticals such as Thallium-201, Tc-99m MIBI, Tc-99m tetrofosmin and Tc-99m MDP was introduced and now actively under the investigation. Several studios have shown that high sensitivity and specificity in detection of primary breast cancer and axillary lymph node metastases using these radiopharmaceuticals. Scintimammography may play important roles in the diagnosis of primary breast cancer, evaluation of the patients with high risk, determining axillary lymph node metastasis, evaluation of the response to chemotherapy, determining the extent of disease, and surveillance of local recurrence. In the future, we should investigate the prognostic role of scintimammography after treatment of breast cancer patients and cost-effectiveness of scintimammography in the detection of primary breast cancer.

• 대한방사선기술학회지:방사선기술과학
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• 제43권2호
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• pp.97-103
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• 2020

This study was conducted by SPECT test at the Department of Nuclear Medicine at Daegu P Hospital from June 1 to October 31, 2019. A 3-way injection material was mounted among inpatients, and a syringe that was administered with radiopharmaceuticals using a ^99mTc labeled compound was secured. We tried to find a way to calculate the dose rate of each radiopharmaceutical and increase the dose rate. As a result of measuring the radioactivity of radio-pharmaceuticals using ^99mTc, the average dose rate of 60 syringes of all 6 radiopharmaceuticals was 93.26±7.34%, and the average dose rate of ^99mTc-DMSA was 77.72%, 15.54% lower than the total. As a way to increase the dosing rate, the average dose rate diluted twice with the remaining amount of syringe after administration using normal saline increased to 95.37±6.99%, and the average dose rate diluted three times increased to 96.32±6.86%. The corresponding sample t-test to compare the pre- and post-dose rates at 1 dilution and 2 and 3 dilutions. As a result of the dilution and 2 dilutions, the probability of significance was 0.013, which was significantly higher than the dilution(p<0.05). The probability of significance for dilution 1 and dilution 3 was 0.016, which was significantly higher than in one dilution(p<0.05). The sum of the average dose rate using the experimental 3-way line was the highest with 98.85±1.42% of ^99mTc, ^99mTc-ECD 98.82±1.26%, ^99mTc-Mebrofenin 98.82 ± 1.16%, ^99mTc-HDP 98.74 ± 1.91%, ^99mTc -MIBI was 98.69 ± 1.48%, and ^99mTc-DMSA was the lowest with 86.47 ± 4.74%. When the number of dilutions was 5 times using 0.5 cc of normal saline and when the number of dilutions was 5 times using 1 cc of normal saline, when the number of dilutions was 5 times using 0.5 cc of normal saline and 1 cc of nomal saline When the number of dilutions was 5 times and the syringe volume was 0.5 cc, there was a statistically significant difference (p<0.05). There was a statistically significant difference when the number of dilutions was 5 times using 1 cc of nomal saline and the number of dilutions was 5 times using 1 cc of normal saline, and the syringe volume was 0.5 cc (p<0.05).

• 대한핵의학회지
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• 제26권2호
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• pp.265-273
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• 1992

Rest gated blood pool scan (Rest GBP scan) and dipyridamole $^{99m}Tc-MIBI$ SPECT were Performed in 34 patients with or suspected coronary artery disease. Both studies were performed within $2\sim32$ days (mean 8.1 days). A significant correlation was present between left ventricular ejection fraction (r= -0.7356, p<0.001) and peak ejection rate and peak filling rate in rest GBP scan and perfusion defect in MIBI SPECT. And there were acceptable correlations (0.05$26.2{\pm}10.8%$, severe hypokinesia, akinesia or dyskinesia in 16 regions: $78.2{\pm}23.7$, p<0.001). These data indicate there is a significant coupling between the degree of myocardial perfusion and the myocardial functional change in coronary artery disease.

• 대한핵의학회지
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• 제39권2호
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• pp.94-99
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• 2005

Electrocardiogram-gated single photon omission computed tomography (SPECT) provides valuable information in the assessment of both myocardial perfusion and ventricular function. Tl-201 is a suboptimal isotope for gating. Tl-201 images are more blurred compared with Tc-99m tracers due to the increased amount of scattered photons and use of a smooth filter. The average myocardial count densities are approximately one-half those of conventional technetium tracers. However, Tl-201 is still widely used because of its well-established utility for assessing myocardial perfusion, viability and risk stratification. Gated SPECT with Tl-201 enables us to assess both post-stress and rest left ventricular volume and function. Previous studies with gated Tl-201 SPECT measurements of ejection fraction (EF), end-diastolic volume (EDV), end-systolic volume (ESV) have shown high correlation with first-pass radionuclide angiography, gated blood pool scan, Tc-99m-MIBI gated SPECT, contrast ventriculography, echocardiography, and 3-dimensional magnetic resonance imaging. However, problems related to these studies include few agreement data of EDV and ESV, use of a reference method that is likely to have the same systemic errors (gated Tc-99m-MIBI SPECT), and other technical factors related to the count density of gated SPECT. With optimization of gated imaging protocols and more validation studies, gated Tl-201 SPECT would be an accurate method to provide perfusion and function information in patients with coronary artery disease.

• 대한핵의학회:학술대회논문집
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• 대한핵의학회 1999년도 제38차 추계학술대회
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• pp.34.2-34.2
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• 1999