• The Korean Journal of Nuclear Medicine
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• v.28 no.1
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• pp.37-43
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• 1994

The coronary collateral vessels have revealed their significance in terms of reduction of infarct size, preservation left ventricular function, and prevention of left ventricular aneurysm in patients with myocardial infarction. The purpose of this study were to evaluated the relation between collateral circulation and $^{99m}Tc$-MIBI Heart SPECT in patient with acute myocardial infarction and their clinical significance. The fifty six MI patients with antegrade TIMI perfusion grade 0 and 1 were studied. The patients were classified into two groups; Group I inclueded 30 patients with grade 2, 3 Collateral flow. Group II inclueded 26 patients with grade 0, 1 Collateral flow. Collateral filling were graded from 0 to 3: 0- none, 1- Filling of side branch only, 2- Partial filling of the epicardial segment, 3- Complete filling of epicardial segment. Clinical variables, left ventricular function, $^{99m}Tc$-MIBI Heart SPECT were analyzed with angiographic finding. Results were following: 1) Collateral visualization was found to be greater in patient with involvement of right coronary artery (RCA). The collateral development site of infarct related artery was RCA 15 cases, left anterior descending artery (LAD) 10 cases, left circumflex artery (LCX) 5 cases, and the collateral circulation from LAD to RCA was 13 cases (40.6%). 2) There was a tendency to be decreased in peak CK activity with group I. 3) The presence of good collateral channels was more frequently $^{99m}Tc$-MIBI reversible perfusion defect (83.4% vs 15.3%, p<0.05). 4) No differences of left ventricular end diastolic volume (LVEDV), left ventricular end systolic volume (LVESV), ejection fraction (EF) were noted between group I and group II. The presence of good collateral channels did affect the frequency of occurrence of $^{99m}Tc$-MIBI reversible perfusion defect.

• The Korean Journal of Nuclear Medicine
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• v.29 no.1
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• pp.79-83
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• 1995

Purpose : We analysed $^{99m}Tc-MAG_3$ renal scans to evaluate renal function of transplanted kidney and to detect various renal transplant complications, measuring the ratio of renal radioactivity at three minutes to that at 20 minutes(elimination index). Material and Methods : The fifty seven renal transplantation recipients were studied. There were 50 normal functioning transplanted kidneys as group I and 7 abnormal function-ing transplanted kidney, including 5 cases of acute renal rejection, 2 cases of acute tubular necrosis as group IIl. The protocol consisted of: (1) $^{99m}Tc-MAG_3$ 740MBq injection intravenously : (2) sequential imaging for 2min(60two-second images) followed by 30min(30 sixty-second images) : (3) drawing of region of interest(ROI) on renal imaging; (4) time-activity corves were generated from renal ROI after background subtraction, and time of maximum activity($T_{max}$) and half time of maximal peak radioactivity($T_{1/2}$) were produced in the renogram curve. (5) EI through Bischof-Delaloye method as determined on the renogram curve. Results : Normal group( I ) shows mean EI of 2.21(95.0% Confidence limit of 2.01-2.87), $T_{max}$ of 154 sec, $T_{1/2}$ of 1,139 sec. Abnormal group(II) shows mean EI of 0.74, $T_{max}$ of 1,466 sec, $T_{1/2}$ of 19,224 sec. The EI, $T_{max}$, $T_{1/2}$, BUN and serum creatinine values are significantly different between normal group(I) and abnormal group(II) (p<0.0001). Conclusion : By measuring EI with $^{99m}Tc-MAG_3$, renal function of transplanted kidney could be easily evaluated and various complications could be detected early.

• Nuclear Engineering and Technology
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• v.48 no.3
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• pp.613-623
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• 2016

Molybdenum-99 ($^{99}Mo$) is the most important isotope because its daughter isotope, technetium-99m ($^{99m}Tc$), has been the most widely used medical radioisotope for more than 50 years, accounting for > 80% of total nuclear diagnostics worldwide. In this review, radiochemical routes for the production of $^{99}Mo$, and the aspects for selecting a suitable process strategy are discussed from the historical viewpoint of $^{99}Mo$ technology developments. Most of the industrial-scale $^{99}Mo$ processes have been based on the fission of $^{235}U$. Recently, important issues have been raised for the conversion of fission $^{99}Mo$ targets from highly enriched uranium to low enriched uranium (LEU). The development of new LEU targets with higher density was requested to compensate for the loss of $^{99}Mo$ yield, caused by a significant reduction of $^{235}U$ enrichment, from the conversion. As the dramatic increment of intermediate level liquid waste is also expected from the conversion, an effective strategy to reduce the waste generation from the fission $^{99}Mo$ production is required. The mitigation of radioxenon emission from medical radioisotope production facilities is discussed in relation with the monitoring of nuclear explosions and comprehensive nuclear test ban. Lastly, the $^{99}Mo$ production process paired with the Korea Atomic Energy Research Institute's own LEU target is proposed as one of the most suitable processes for the LEU target.

• The Korean Journal of Nuclear Medicine
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• v.37 no.6
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• pp.382-392
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• 2003

Purpose: Uptakes of Tc-99m MIBI (MIBI) and Tc-99m tetrofosmin (tetrofosmin) in human non-small cell lung cancer A549, multidrug-resistance associated protein (MRP) expressing cell, were investigated in vitro and in vivo. Materials and Methods: Western blot analysis and immunohistochemistry were used for detection of MRP in A549 cells with anti-MRPr1 antibody. Cellular uptakes of two tracers were evaluated at $100{\mu}M$ of verapamil (Vrp), $50{\mu}M$ of cyclosporin A (CsA) and $25{\mu}M$ of butoxysulfoximide (BSO) after incubation with MIBI and tetrofosmin for 30 and 50 min at $37^{\circ}C$, using single cell suspensions at $1{\times}10^6cells/ml$. Radioactivities in supernatants and pellets were measured with gamma well counter. A549 cells were inoculated in each flanks of 24 nude mice. Group 1 (Gr1) and Gr3 mice were treated with only MIBI or tetrofosmin, and Gr2 and Gr4 mice were treated with 70mg/kg of CsA i.p. for 1 hour before injection of 370KBq of MIBI or tetrofosmin. Mice were sacrificed at 10, 60 and 240 min. Radioactivities of organs and tumors were expressed as percentage injected dose per gram of tissue (%ID/gm). Results: Western blot analysis of the A549 cells detected expression of MRPr1 (190 kDa) and immunohistochemical staining of tumor tissue for MRPr1 revealed brownish staining in cell membrane but not P-gp. Upon incubating A549 cells for 60 min with MIBI and tetrofosmin, cellular uptake of MIBI was higher than that of tetrofosmin. Coincubation with modulators resulted in an increase in cellular uptakes of MIBI and tetrofosmin. Percentage increase of MIBI was higher than that of tetrofosmin with Vrp by 623% and 427%, CsA by 753% and 629% and BSO by 219% and 140%, respectively. There was no significant difference in tumoral uptakes of MIBI and tetrofosmin between Gr1 and Gr3. Percentage increases in MIBI (114% at 10 min, 257% at 60 min, 396% at 240 min) and tetrofosmin uptake (110% at 10 min, 205% at 60 min, 410% at 240 min) were progressively higher by the time up to 240 min with CsA. Conclusion: These results indicate that MIBI and tetrofosmin are suitable tracers for imaging MRP-mediated drug resistance in A549 tumors. MIBI may be a better tracer than tetrofosmin for evaluating MRP reversal effect of modulators.

• 대한핵의학회:학술대회논문집
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• 2000.05a
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• pp.52.1-52.1
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• 2000

• Proceedings of the Korea Contents Association Conference
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• 2014.11a
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• pp.431-432
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• 2014

본 연구는 핵의학과에서 사용하는 $^{99m}Tc$에서 방출되는 광자에너지에 대하여 거리에 따른 인체에 대한 선량당량을 평가하였다. 그 결과 주사기 차폐기구 유무에 따라 선량당량이 차이를 보였으며, 심부선량은 차폐를 하지 않은 경우 평균 $216.026{\mu}Gy/h$, 1 mm 텅스텐 차폐를 하였을 경우 평균 $4.240{\mu}Gy/h$, 2 mm 텅스텐의 경우 평균 0.124 uGy/h의 선량을 보였다. 이에 따라 주사기 차폐기구를 필수적으로 사용하여야 하며 종사자 개개인의 피폭 관리에 항상 유념하여야 한다. 또한 본 연구결과를 바탕으로 종사자의 피폭 감소 방안에 대한 연구가 지속적으로 이루어 져야할 것으로 생각된다.

• The Korean Journal of Nuclear Medicine
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• v.34 no.5
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• pp.393-402
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• 2000

Purpose: Tc-99m-MIBI (MIBI) and Tc-99m-Tetrofosmin (TF) are commonly used for scintimammog (SMM). We compared the diagnostic ability of SMM using Tc-99m-MIBI and Tc-99m-TF for the diagnosis of breast mass. Materials and Methods: The study subjects were comprised of 123 breast lesior 86 normal breasts of 114 patients who underwent SMM. Bilateral prone images and anterior supine images obtained at 5 minutes and 1 or 3 hours after intravenous injection of 740 MBq of either MIBI or TF. of tumors were not significantly different between the MIBI and TF groups. First, two observers read the SMM without clinical information (1st interpretation), then read again with information about location (2nd interpretation). Sensitivity and specificity of each radiopharmaceutical for the diagnosis of cancer were evaluated in terms of image acquisition time, tumor size, and location. Results: The SMM a good agreement between two observers for 1st and 2nd interpretation, except for TF SMM at 3 hr. first interpretation, the sensitivities at 5 min, 1 hr, and 3 hr were not significantly different between MIBI TF SMM (81.6%, 80.0%, 60.9% in MIBI vs. 88.9%, 80.6%, 42.9% in TF), although the sensitivities of images were significantly lower than 5 min images in both MIBI and TF SMM. The specificity of TF at was superior to that of MIBI (81.5%, 90.0%, 82.9% in MIBI vs. 96.7%, 100%, 90.0% in TF, p<0.01 MIBI TF at 5 min). For the second interpretation with information of mass location, the sensitivities at 3 hr were significantly lower than 5 min images (86.8%, 86.7%, 78.3% in MIBI vs. 88.9%, 93.5%, 57.1% between MIBI and TF SMM. However, there was no significant difference in the specificity (60.0%, 75.0% for MIBI vs. 86.7%, 100%, 100% for TF). MIBI and TF SMM showed lower sensitivities for the with less than 1 cm than tumors with more than 1 cm. However, the location of tumors did not sensitivity and specificity between MIBI and TF SMM. Conclusion: The ability for the differential of breast tumor is similar between MIBI and TF SMM, and delayed image is not necessary. TF may be than MIBI considering the specificity of SMM without clinical information and labeling convenience.

• The Korean Journal of Nuclear Medicine
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• v.32 no.6
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• pp.497-508
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• 1998

Purpose: Using rest T1-201/dipyridamole stress gated Tc-99m-MIBI/ 24 hour delay T1-201 SPECT, we investigated the predictive values of the markers of the stress-rest reversibility (Rev), T1-201 rest perfusion (Rest), T1-201 24 hour redistribution (Del) and Tc-99m-MIBI gated systolic thickening (Thk) for wall motion improvement after coronary artery bypass surgery. Materials and Methods: In 39 patients (M;F= 34:5, age $58{\pm}8$), preoperative and postoperative (3 months) SPECT were compared. 24 hour delayed SPECT was done in 16 patients having perfusion defects at rest. Perfusion or wall motion was scored from 0 to 3 (0: normal to 3: defect or dyskinesia). Wall motion was abnormal in 142 segments among 585 segments of 99 artery territories which were surgically revascularized. Results: After bypass surgery, ejection fraction increased from $37.8{\pm}9.0%$ to $45.5{\pm}12.3%$ in 22 patients who had decreased ejection fraction preoperatively. Wall motion improved in 103 (72.5%) segments among 142 dysfunctional segments. Positive predictive values (PPV) of Rev, Rest, Del, and Thk were 83%, 76%, 43%, and 69% respectively. Negative predictive values (NPV) of Rev, Rest, Del, and Thk were 48%, 44%, 58%, and 21%, respectively. Rest/gated stress/delay SPECT had PPV of 74% and NPV of 46%. Though univariate logistic regression analysis revealed Rev (p=0.0008) and Rest (p=0.024) as significant predictors, stepwise multivariate test found Rev as the only good predictor (p=0.0008). Conclusion: Among independent predictors obtained by rest T1-201/ stress gated Tc-99m-MIBI/ delayed T1-201 myocardial SPECT for wall motion improvement after bypass surgery, stress-rest reversibility was the single most useful predictor.

• The Korean Journal of Nuclear Medicine
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• v.16 no.2
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• pp.85-89
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• 1982

Patients with diffusely increased uptake in both kindeys("hot kidney") on the $^{99m}Tc-MDP$ bone imagings were evaluated. Total incidence of the "hot kidney" was 2.7% (56/2053). Among 56 patients with "hot kidney", the most common diseases were malignancies (30), and the remainders were composed of renal diseases(11) and other disease group(16). We report the possible factors for the "hot kidney" with brief review of some literatures.

• The Korean Journal of Nuclear Medicine
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• v.22 no.2
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• pp.181-185
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• 1988

Since hepatocyte clearance, leading edge parencymal transit time and biliary excretion can be evaluated separately with hepatobiliary scan using $^{99m}Tc-DISIDA$, hepatobiliary scan may be useful in differentiating intrahepatic cholestasis from extrahepatic cholestasis. Excretory liver function was analysed in 13 healthy subjects and 11 patients with clinically suspected hepatocellular disease and 9 patients with extrahepatic biliary obstruction confirmed by surgery, radiological and clinical evidence. Indices of total liver activity (% TLA), liver parechymal uptake (% LPU), heart pool clearance (% HPC) and liver-heart rate (% LHR) were calculated from time activity curve over heart and liver. Compared with healthy subjects, significant reduction (p<0.05) in total liver activity (% TLA) and liver-heart rate (% LHR) was observed in all patients group. But no useful indices was demonstrated in differentiating hepatocellular disease from extrahepatic biliary obstruction.