• The Korean Journal of Nuclear Medicine
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• v.32 no.1
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• pp.1-9
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• 1998

Gated myocardial SPECT and attenuation correction gave birth to new insights into the pathophysiology of ischemic myocardial perfusion and function in clinical routine practice. Gated myocardial Tc-99m-compound SPECT improved diagnostic accuracy of coronary artery disease and enabled us to observe motion and thickening of myocardial walls as well as myocardial perfusion at the same time. Quantitative and qualitative assessment of myocardial performance and perfusion let us to understand the myocardial physiology in ischemia and infarction. In every patient who underwent gated perfusion SPECT, we will find ejection fraction, left ventricular volumes and regional wall motion. There are hopes to use gated TI-201 SPECT for the same purpose and to use gated SPECT for evaluation of wall motion and thickening at stress or immediate post-stress. Attenuation correction could improve diagnostic accuracy mainly by increasing normalcy ratio or performance of non-expert physicians. Both gated methods and attenuation correction improved specificity of non-expert physicians in diagnosing patients with moderate pretest likelihood. New imaging techniques will fill the desire of cardiologists to examine function and perfusion, and possibly metabolism in their clinical routine practice.

• The Korean Journal of Nuclear Medicine
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• v.39 no.2
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• pp.114-117
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• 2005

As the indication of percutaneous coronary intervention (PCI) has expanded to the more difficult and complicated cases, frequent restenosis is still expected after PCI. According to AHA/ACC guideline of the present time, routine use of myocardial perfusion single photon emission tomography (SPECT) is not recommended after coronary intervention, but symptom itself or exercise EKG is not enough for the detection of restensis or for the prediction of event-free survival. In high risk and/or symptomatic subjects, direct coronary angiography is required myocardial perfusion SPECT could detect restenosis in 79% of the patients if performed 2 to 9 months after PCI. Reversible perfusion decrease in the myocardial perfusion SPECT is known to be the major prognostic indicator of major adrerse cardiac event in PCI patients and also the prognosis is benign in the patients without reversible perfusion decrease. Though the cumulated specificity is 79% in the literature and optimal timing of myocardial perfusion SPECT is in controversy, SPECT is recommended even in asymptomatic patients at 3 to 9 months after PCI. Considering the evidences recently reported in the literature, myocardial perfusion SPECT is useful for risk stratification and detection of coronary artery restenosis requiring re-intervention in the asymptomatic patients after PCI.

• The Korean Journal of Nuclear Medicine
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• v.37 no.4
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• pp.207-218
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• 2003

Myocardial perfusion imaging has been increasingly used to provide prognostic data and guidance on the choice of appropriate management of patients with known or suspected coronary artery disease. The electrocardiogram gated myocardial SPECT program is corning into wide use with an advent of $^{99m}Tc-labeled$ tracers and an improvement of SPECT machines. The gated technique permits measurement of important cardiac prognostic indicators without any further discomforts or radiation burden in patients underwent standard myocardial perfusion SPECT. In addition, gated study significantly improves diagnostic yield by reducing the number of borderline interpretations and could find myocardial stunning and viable myocardium. Gated single photon emission computed tomography (SPECT) imaging allows the automated calculation of end-diastolic volume, end-systolic volume, ejection fraction, myocardial mass and the assessment of regional wall motion and thickening, and it have dramatically improved assessment of coronary artery disease in routine nuclear practice. This allows the simultaneous assessment of both perfusion and function within the same acquisition, and serves as a cost-effective technique for providing more diagnostic data with fewer diagnostic tests. Because the diagnostic and prognostic power derived from knowledge of left ventricular function can be added to that provided by assessing myocardial perfusion, gated SPECT imaging has rapidly gained widespread acceptance and is now used on a routine clinical basis in a growing number of laboratories, including South Korea. The gated SPECT technique for measurement of left ventricular parameters has been validated against a variety of well established techniques. In this work, overview of gated myocardial perfusion SPECT focus on functional parameters is presented.

• The Korean Journal of Nuclear Medicine
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• v.39 no.2
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• pp.75-81
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• 2005

Myocardial perfusion and function can be quantified using SPECT and PET. There was controversy over the usefulness of the correction techniques for physical artifacts, such as photon attenuation and scatter, in the quantification of myocardial perfusion using SPECT. However, the cumulated results of many investigations have leaded the consensus on the usefulness of the correction procedures to improve the accuracy and specificity of the myocardial SPECT in the assessment of coronary artery diseases. Although the clinical value of the myocardial perfusion PET has not been preyed yet, the absolute myocardial blood flow and perfusion reserve values quantified using myocardial PET are employed in many basic investigations. In this paper, the methods for the quantitative myocardial SPECT and PET will be reviewed.

• The Korean Journal of Nuclear Medicine
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• v.31 no.1
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• pp.50-56
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• 1997

Gated SPECT can evaluate the regional wall motion of the heart. We evaluated the regional wall motion of the perfusion abnormality in conventional perfusion SPECT with gated SPECT. In case of suspicious perfusion abnormalities, we tried to differentiate the artifact from true abnormality in coronary vascular disease using gated SPECT. We thought that artifacts would have normal wall motion, whereas fixed defects with decreased wall motion would probably represent coronary artery disease. A total of 275 patients who were performed coronary angiography and T1-201 rest/Tc-99m MIBI dipyridamole stress gated SPECT within 2 months were enrolled. In coronary angiography, stenosis more than 50% was considered as coronary artery disease. After injection of 111MBq T1-201 rest image was obtained on triple head SPECT system. 370MBg Tc-99m MIBI was used for the stress image. Eight-frame per-cardiac-cycle gated Tc-99m SPECT studies were done. All the images were analyzed visually. Using perfusion SPECT, the overall sensitivity and specificity were 87% and 55% respectively. Regarding artery territory, sensitivity and specificity were 68% and 73% for left anterior descending artery(LAD), 62% and 78% for right coronary artery(RCA), 42% and 90% for left ciramflex artery(LCX). Using gated SPECT, the overall sensitivity and specificity were 87% and 66% respectively. Sensitivity and specificity were 68% and 78% for LAD, 62% and 79% for RCA, 42% and 90% for LCX. Among 21 false positive cases in perfusion SPECT, 5 cases were interpreted as true negative with gated SPECT. We conclude that gated SPECT provides a valuable adjunct to perfusion SPECT in characterizing perfusion abnormalities and to improve specificity.

• The Korean Journal of Nuclear Medicine
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• v.32 no.4
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• pp.314-324
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• 1998

Purpose: This study was performed to evaluate the outcome of encephalo-duro-arterio-synangiosis (EDAS) surgery with rest/acetazolamide Tc-99m HMPAO SPECT in moyamoya disease. Materials and Methods: Rost/acetazolamide subtraction SPECT with consecutive acquisition were done before and 2 months after 21 EDAS surgeries in 18 patients. Perfusion decrease was graded visually for 14 areas of each hemisphere as 0 (normal) to 3 (defect) using 4 point scoring system. Postoperative rest perfusion or perfusion reserve was compared with preoperative ones. Results: Among 294 areas of 21 hemispheres, rest perfusion abnormality was found in 91 areas of 15 hemispheres. Decrease of perfusion reserve was found in 146 areas of 18 hemispheres. Six hemispheres having normal rest perfusion and 12 of 15 hemispheres having rest perfusion abnormality showed reserve decrease. Three having rest perfusion defect did not change after acetazolamide in preoperative SPECT. After operation, 16 patients (89%) demonstrated clinical improvement. Fifteen among 18 hemispheres (83%) with decreased reserve improved. Rest perfusion abnormality improved in 6 among the 15 hemispheres (40%). The areas having rest perfusion and/or reserve decrease improved in 87 among 146 areas (60%). Decrease of reserve, improved in 85% (68/80). However, areas without reserve decrease also improved in 29% (19/66). The better was preoperative rest perfusion in involved areas or the more decreased vascular reserve, the more improved perfusion and reserve after operation. Conclusion: We conclude that assessment of perfusion and Perfusion reserve using rest/acetazolamide brain perfusion SPECT predict the surgical outcome in patients with moyamoya disease.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.4
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• pp.285-291
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• 2008

Purpose: Although automatic quantification software of myocardial perfusion SPECT provides highly objective and reproducible quantitative measurements, there is still some limitation in the direct use of quantitative measurements. In this study we derived parameters using normal variation of perfusion measurements, and tried to test the usefulness of these parameters. Materials and Methods: In order to calculate normal variation of perfusion measurements on myocardial perfusion SPECT, 55 patients (M:F = 28:27) of low-likelihood for coronary artery disease were enrolled and $^{201}TI$ rest/$^{99m}Tc$-MIBI stress SPECT studies were performed. Using 20-segment model, mean (m) and standard deviation (SD) of perfusion were calculated in each segment. As a myocardial viability assessment group, another 48 patients with known coronary artery disease, who underwent coronary artery bypass graft surgery (CABG) were enrolled. $^{201}TI$ rest/$^{99m}Tc$-MIBI stress / $^{201}TI$ 24-hr delayed SPECT was performed before CABG and SPECT was followed up 3 months after CABG. From the preoperative 24-hr delayed SPECT, $Q_{delay}$ (perfusion measurement), ${\Delta}_{delay}$ ($Q_{delay}$ - m) and $Z_{delay}$ (($Q_{delay}$ - m)/SD) were defined and diagnostic performances of them for myocardial viability were evaluated using area under curve (AUC) on receiver operating characteristic (ROC) curve analysis. Results: Segmental perfusion measurements showed considerable normal variations among segments. In men, the lowest segmental perfusion measurement was $51.8{\pm}6.5$ and the highest segmental perfusion was $87.0{\pm}5.9$, and they are $58.7{\pm}8.1$ and $87.3{\pm}6.0$, respectively in women. In the viability assessment $Q_{delay}$ showed AUC of 0.633, while those for ${\Delta}_{delay}$ and $Z_{delay}$ were 0.735 and 0.716, respectively. The AUCs of ${\Delta}_{delay}$ and $Z_{delay}$ were significantly higher than that of $Q_{delay}$ (p = 0.001 and 0.018, respectively). The diagnostic performance of ${\Delta}_{delay}$, which showed highest AUC, was 85% of sensitivity and 53% of specificity at the optimal cutoff of -24.7. Conclusion: On automatic quantification of myocardial perfusion SPECT, the normal variation of perfusion measurements were considerable among segments. In the viability assessment, the parameters considering normal variation showed better diagnostic performance than the direct perfusion measurement. This study suggests that consideration of normal variation is important in the analysis of measurements on quantitative myocardial perfusion SPECT.

• The Journal of Internal Korean Medicine
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• v.22 no.3
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• pp.437-442
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• 2001

For ischemic cerebrovascular disease, it is well known that early luxury perfusion is related to a good clinical outcome and single photon emission computed tomography(SPECT) has the potential for providing useful information about regional cerebral blood flow. We report one case of Rt. MCA infarction mainly treated by oriental medicine and revealed luxury perfusion without thrombolysis. In acute stage, neurological deficits of the patient were very severe. 99mTc-HMPAO SPECT images obtained 10days after the attack showed large perfusion defect in the Rt. MCA territory. We followed up 99mTc-HMPAO SPECT 40days after the ictus. Despite of the poor early perfusion, we found considerably improved perfusion and neurological improvement.

• The Korean Journal of Nuclear Medicine
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• v.34 no.5
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• pp.426-432
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• 2000

After surgical operation in patients with arteriovenous malformation (AVM), normal pressure perfusion breakthrough (NPPB) is one of the major complications. Brain perfusion SPECT with acetazolamide stress was known to be useful to evaluate the vascular reserve in several neurological and neurosurgical conditions. The authors performed acetazolamide brain perfusion SPECT in patients with AVM and compared the brain perfusion in the post-operative clinical courses. The acetazolamide brain perfusion SPECT was helpful in defining the prognosis of the patients with AVM. We describe 4 patients with AVM who had acetazolamide brain perfusion SPECT to examine the prognosis.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.2
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• pp.60-64
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• 2011

Purpose: The brain perfusion SPECT is the examination which is able to know adversity information related brain disorder. But brain perfusion SPECT has also high failure rates by patient's motions. In this case, we have to use two days method and patients put up with many disadvantages. We think that we don't use two days method in brain perfusion SPECT, if we can use registration method. So this study has led to look over registration method applications in brain perfusion SPECT. Materials and Methods: Jaszczak, Hoffman and cylindrical phantoms were used for acquiring SPECT image data on varying degree in x, y, z axes. The phantoms were filled with $^{99m}Tc$ solution that consisted of a radioactive concentration of 111 MBq/mL. Phantom images were acquired through scanning for 5 sec long per frame by using Triad XLT9 triple head gamma camera (TRIONIX, USA). We painted the ROI of registration image in brain data. So we calculated the ROIratio which was different original image counts and registration image counts. Results: When carring out the experiments under the same condition, total counts differential was from 3.5% to 5.7% (mean counts was from 3.4% to 6.8%) in phantom and patients data. In addition, we also run the experiments in the double activity condition. Total counts differential was from 2.6% to 4.9% (mean counts was from 4.1% to 4.9%) in phantom and patients data. Conclusion: We can know that original and registration data are little different in image analysis. If we use the image registration method, we can improve disadvantage of two days method in brain perfusion SPECT. But we must consider image registration about the distance differences in x, y, z axes.