• 대한핵의학회:학술대회논문집
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• 1997.05a
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• pp.150-150
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• 1997

• The Korean Journal of Nuclear Medicine
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• v.38 no.2
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• pp.180-189
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• 2004

Although the outcome of cancer patients after cytotoxic chemotherapy is related diverse mechanisms, multidrug resistance (MDR) for chemotherapeutic drugs due to cellular P-glycoprotein (Pgp) or multidrug-resistance associated protein (MRP) is most important factor in the chemotherapy failure to cancer. A large number of pharmacologic compounds, including verapamil, quinidine, tamoxifen, cyclosporin A and quinolone derivatives have been reported to overcome MDR. Single photon emission computed tomography (SPECT) and positron emission tomography (PET) are available for the detection of Pgp and MRP-mediated transporter. $^{99m}Tc$-MIBI and other $^{99m}Tc$-radiopharmaceuticals are substrates for Pgp and MRP, and have been used in clinical studies for tumor imaging, and to visualize blockade of PgP-mediated transport after modulation of Pgp pump. Colchicine, verapamil and daunorubicin labeled with $^{11}C$ have been evaluated for the quantification of Pgp-mediated transport with PET in vivo and reported to be feasible substrates with which to image Pgp function in tumors. Leukotrienes are specific substrates for MRP and $N-[^{11}C]acetyl-leukotriene$ E4 provides an opportunity to study MRP function non-invasively in vivo. SPECT and PET pharmaceuticals have successfully used to evaluate pharmacologic effects of MDR modulators. Imaging of MDR and reversal of MDR with bioluminescence in a living animal is also evaluated for future clinical trial. We have described recent advances in molecular imaging of MDR and reviewed recent publications regarding feasibility of SPECT and PET imaging to study the functionality of MDR transporters in vivo.

• The Korean Journal of Nuclear Medicine
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• v.27 no.2
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• pp.155-160
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• 1993

The identification of viable myocardium in patients with coronary artery disease and left ventricular dysfunction is an issue of increasing clinical relavance in the current era of myocardial revascularization. There are at least two forms of reversible myocardial dysfunction. Early reperfusion does not always lead to immediate functional improvement; rather, the return of contractility in tissue salvaged by reperfusion is delayed for hours, days or even weeks, a phenomenon that has been termed "stunned myocardium". Some patients with coronary artery disease show myocardial dysfunction at rest which are associated with reduced perfusion, and which disappear after revascularization; this phenomenon has been termed "hibernating myocardium". Recently, cardiac imaging techniques that evaluate myocardial viability on the basis of perfusion-contraction mismatch and inotropic reserve have gained substantial popularity and clinical success. This review focus on the application of $^{201}TI$ and $^{99m}Tc-MIBI$ to address myocardial viability in patients with hibernating and stunned myocardium. It is clear that 4-hour redistribution images of $^{201}TI$ underestimate ischemia and overestimate scar. Delayed imaging and reinjection imaging have been developed for the assessment of viability. Among many protocols suggested, stress-redistribution-reinjection imaging gained most popularity. Although $^{99m}Tc-MIBI$ could identify myocardial viability, $^{201}TI$ reinjection technique was regarded as superior to it. In conclusion, $^{201}TI$ stress, 4-hr rest redistribution, and reinjection imaging technique may be the most preferable method for evaluation of myocardial viability.

• The Korean Journal of Nuclear Medicine
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• v.28 no.2
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• pp.172-176
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• 1994

As the Tc-99m-MIBI myocardial SPECT demonstrated wide application in the diagnosis of myocardial function, the quantitative and severity-dependent information is currently re quired. In this study, we proposed a computerized method for scoring the fixed defects in terms of extent-weighted severity and for identifying the reversibility in ischemic regions. At the first stage of this method, the transverse slices were reconstructed with 0.4 Nyquist freq. and order 5 Butterworth filter. From the oblique/sagittal slices, maximal count per pixel circumferential profiles were extracted for each sector, and then stress/redist. polar maps were normalized and plotted. For reversibility, the stress polar map was subtracted from the de-layed image and positive-valued pixels were categorized into three grades. The extent-weight-ed severity scores were calculated using the assigned grades and their number of pixels. This procedure was done automatically and the reversibility and severity scores were produced for each of the coronary territories (LAD, RCA, LCX) or any combination of these. Clinical ap-plication has shown that the changes In reversibility scores after PTCA were correlated linearly with the pre PTCA scores(r>0.8) in postinfarct cases as well as in angina, and severity scores of persistent defects in stress/rest SPECT study matched to the regional ejection fraction and visual analysis of regional wall motion of gated blood pool scan(r>0.6). We conclude that the computerized severity scoring method for the analysis of myocardial SPECT could be useful in the assessment of the myocardial ischemia and fixed defect.

• The Korean Journal of Nuclear Medicine
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• v.29 no.4
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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.

• The Korean Journal of Nuclear Medicine
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• v.35 no.4
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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.

• Journal of radiological science and technology
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• v.43 no.2
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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).

• The Korean Journal of Nuclear Medicine
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• v.26 no.2
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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.

• The Korean Journal of Nuclear Medicine
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• v.39 no.2
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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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• 1999.11a
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• pp.34.2-34.2
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• 1999