• The Korean Journal of Nuclear Medicine
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• v.39 no.4
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• pp.246-251
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• 2005

Purpose: There has been many reports for the effect of attenuation correction on myocardial perfusion SPECT. We studied the effect of attenuation correction with CT (computed tomography) in patients with normal coronary angiography. Materials and Methods: Fifteen patients with normal coronary artery on angiography and low likelihood of coronary artery disease were enrolled in this study (male: 6, female: 9, mean age: $58{\pm}8$ year). Myocardial perfusion SPECT was done with Millennium VG with Hawkeye device (GE, SPECT/CT camera). A visual analysis and polar map quantification (Emory tool box) was performed. In quantitative analysis, percent uptake of each myocardial wall on polar map (percent of maximal uptake) was compared between non-corrected (NC) and corrected (AC) images. Results: Visual analysis showed AC images led to an increase of uptake in the inferior wall, but decrease of uptake in the anterior wall, apex and septum. liver activity is also increased in AC images. In quantitative analysis, the percent uptake is decreased in the anterior wall, apex and septum, but increased in the inferior wall. It is helpful to interpret the images in the inferior wall after AC, but difficult in the apex and anterior wall after AC. Conclusion: AC is helpful in the inferior wall. But in the apex or anterior wall, AC must be carefully applied to normal perfused myocardium.

• Clinical and Experimental Pediatrics
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• v.51 no.7
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• pp.736-741
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• 2008

Purpose : The incidence of thromboembolic episodes in children with nephrotic syndrome (NS) is low; however, these episodes are often severe. Moreover, both pulmonary thromboembolism (PTE) and renal vein thrombosis (RVT) rarely show clinical symptoms. This study was performed to determine the benefits of routine screening in the detection of thrombosis in childhood NS. Methods : Among 62 children with nephrotic syndrome, a total of 54 children (43 males, 11 females) were included in this study. When the patients experienced their first NS episode, we performed renal Doppler ultrasonography in order to detect RVT. To rule out the possibility of PTE, a lung perfusion scan was performed. Computed tomographic (CT) pulmonary angiography was recommended to patients who showed possible signs of PTE. All patients were evaluated for clinical signs of thrombosis, biochemical indicators of renal disease, as well as clotting and thrombotic parameters. Results : RVT or related clinical symptoms were not observed in any children. Based on the findings of the lung perfusion scans, 15 patients (27.8%) were observed with as a high probability of PTE. We were able to perform a CT pulmonary angiography only on 12 patients, and 5 patients were diagnosed with PTE (prevalence 8.1%). The serum fibrinogen level in the group with PTE was significantly higher ($776.7{\pm}382.4mg/dL$, P<0.05) than that in the group without PTE, and other parameters were not significantly different between each group. Conclusion : Further studies are required for clarifying the role of renal Doppler ultrasonography for the detection of RVT in NS. Children with NS who developed non-specific respiratory symptoms should be evaluated for the diagnosis of PTE. In the management of NS, a lung perfusion scan should be performed at the time of the initial episode of NS regardless of the pulmonary symptoms, since patients having PTE are either often asymptomatic, or present with nonspecific symptoms.

• The Korean Journal of Nuclear Medicine
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• v.30 no.1
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• pp.112-117
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• 1996

Objective: Standard stress/rest Tc-99m MIBI and T1-201 myocardial perfusion study have some limitations such as stress/rest image overlap for Tc-99m-MIBI, low energy for T1-201 and long period of study time for two separate studies. Separate acquisition rest T1-201/stress Tc-99m MIBI dual isotope study is a potentially efficient myocardial perfusion imaging protocol that combines the high resolution of Tc-99m for stress perfusion assessment and T1-201 for viability assessment. This study assessed the usefulness and diagnostic accuracy for this new approach. Methods: We tried to evaluate sensitivity and specificity of dual isotope separate acquisition protocol in 67 patients. Immediately after resting T1-201 SPECT data was acquired, dipyridamole stress Tc-99m MIBI myocardial perfusion study was performed. Visual analysis was carried out qualitatively with 0 to 3 scoring system for 17 segments of left ventricle in the reconstructed horizontal long axis and short axis slices. Results: Total study was completed within 3 hours. In angiographic correlation, dual isotope SPECT demonstrated high sensitivity(85%) and in a small group of patients, high specificity was also observed (100%). Conclusion: Combined thallium-201/stress Tc-99m MIBI SPECT displayed similiar diagnostic accuracy to protocol using stress/rest Tc-99m MIBI SPECT. This protocol was completed in shorter period than the previous protocols and therefore enhance laboratory throughput and patients convenience.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.5
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• pp.467-475
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• 1997

Although one of the major physiological functions of taurine(2-aminoethanesulfonic acid) is the inhibitory action on the central nervous system(CNS), the mechanism of taurine in controlling the neuronal excitation in the CNS has been in controversy. Electrically evoked pEPSP and spontaneous activity induced by the perfusion of low $Mg^{++}-ACSF$ were recorded in the CA1 pyramidal cell layer of the hippocampal slice. To test the inhibitory effect of taurine on spontaneous responses, taurine was treated for 2 min at various concentrations(1 mM-10 mM). Taurine reduced the spontaneous activity by 22.2% at 1 mM, and 100% at 2 mM in low $Mg^{++}-ACSF$. Evoked response was induced by electrical stimulation of Schaffer collateral-commissural fibers. Taurine reduced the evoked response by 11.68% at 3 mM, and 24.25% at 5 mM. Even 20 mM of taurine reduced the evoked response only by 24 % after 5 min treatment. That is, the inhibitory efficacy was much higher in spontaneous activity than in evoked response. The $GABA_A$ receptor antagonist, 100 uM bicuculline, blocked the inhibitory action of taurine, while $GABA_B$ receptor antagonist, 700 uM phaclofen, did not. Taurine blocked the spontaneous activity in the presence of CNQX, and did not block the electrically evoked responce in the presence of APV. The results suggest that taurine causes hyperpolarization in the cell by binding to $GABA_A$ receptor and preferentially attenuates NMDA receptor-mediated hyperexcitation, leaving synaptic transmission unmodified.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.2
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• pp.186-193
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• 2007

The prevalence of diabetes has increased to 8% of population. Unlike type 2 diabetes in the western countries, Korean diabetic patients are nonobese and have low serum insulin levels. As the increased prevalence of diabetes and the peculiar characteristics may be related to dietary fat contents, we determined their effects on insulin resistance, insulin secretion and pancreatic $\beta-cell$ mass in 90% pancreatectomized (Px) diabetic rats in the present study. The rats were provided with low fat diet (LF, 10 energy% fat), moderate fat diet (MF, 25 energy% fat) and high fat diet (HF, 40 energy% fat) for 6 months. HF increased body weight and epidydimal fat pads parallel with increased food intake compared to LF and MF. Fasting serum glucose and insulin levels and homeostasis model assessment of insulin resistance were higher in HF, compared to LF and MF, indicating that HF increased insulin resistance. Rats fed LF and MF diets reduced insulin resistance, but only rats fed MF improved pancreatic $\beta-cell$ mass and insulin secretion capacity, measured by hyperglycemic clamp and in situ pancreatic perfusion. LF had low insulin secretion capacity and pancreatic $\beta-cell$ mass, indicating the increased possibility of diabetic prevalence and progression. MF increased $\beta-cell$ mass by stimulating $\beta-cell$ proliferation and neogenesis and reducing $\beta-cell$ apoptosis. In conclusion, MF is effective for the prevention of prevalence and progression of diabetes.

• The Korean Journal of Nuclear Medicine Technology
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• v.22 no.1
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• pp.90-97
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• 2018

Purpose The lung segment ratio which is obtained through quantitative analyses of lung perfusion scan images is calculated to evaluate the lung function pre and post surgery. In this Study, the planar image production methods by using Q-Metrix (GE Healthcare, USA) program capable of not only quantitative analysis but also computation of the segment ratio after having performed SPECT/CT are comparatively evaluated. Materials and Methods Lung perfusion scan and SPECT/CT were performed on 50 lung cancer patients prior to surgery who visited our hospital from May 1, 2015 to September 13, 2016 by using Discovery 670(GE Healthcare, USA) equipment. AP(Anterior Posterior)method that uses planar image divided the frontal and rear images into three rectangular portions by means of ROI tool while PO(Posterior Oblique)method computed the segment ratio by dividing the right lobe into three parts and the left lobe into two parts on the oblique image. Segment ratio was computed by setting the ROI and VOI in the CT image by using Q-Metrix program and statistically analysis was performed with SPSS Ver. 23. Results Regarding the correlation concordance rate of Q-Metrix and AP methods, RUL(Right upper lobe), RML(Right middle lobe) and RLL(Right lower lobe) were 0.224, 0.035 and 0.447. LUL(Left upper lobe) and LLL(Left lower lobe) were found to be 0.643 and 0.456, respectively. In the PO method, the right lobe were 0.663, 0.623 and 0.702, respectively, while the left lobe were 0.754 and 0.823. When comparison was made by using the Paired sample T-test, Right lobe were $11.6{\pm}4.5$, $26.9{\pm}6.2$ and $17.8{\pm}4.2$, respectively in the AP method. Left lobe were $28.4{\pm}4.8$ and $15.4{\pm}5.6$. The right lobe of PO had values of $17.4{\pm}5.0$, $10.5{\pm}3.6$ and $27.3{\pm}6.0$, while the left lobe had values of $21.6{\pm}4.8$ and $23.1{\pm}6.6$, thereby having statistically significant difference in comparison to the Q-Metrix method for each of the lobes (P<0.05). However, there was no statistically significant difference in Right middle lobe (P>0.05). Conclusion The AP method showed low concordance rate in correlation with the Q-Metrix method. However, PO method displayed high concordance rate overall. although AP method had significant differences in all lobes, there was no significant difference in Right middle lobe of PO method. Therefore, at the time of production of lung perfusion scan results, utilization of Q-Metrix method of SPECT/CT would be useful in computation of accurate resultant values. Moreover, it is deemed possible to expect obtain more practical sectional computation result values by using PO method at the time of planar image acquisition.

• Journal of Chest Surgery
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• v.35 no.9
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• pp.664-667
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• 2002

Extracorporeal membrane oxygenation(ECMO) provides stable oxygenation to prevent elevation of pulmonary vascular resistance and bypasses a significant part of cardiac output to the pulmonary vascular bed to reduce pulmonary perfusion pressure. In addition, ECMO prevents right heart failure and low cardiac output by means of ventricular assist and reduction in volume load to right ventricle. As a result, ECMO can be used for the treatment of pulmonary hypertensive crisis after surgery for congenital heart disease, especially when it is refractory to conventional measures. We report a case of postoperative pulmonary hypertensive crisis, developed in a 37-year-old male with patent ductus arteriosus with secondary pulmonary hypertension, which was successfully managed including ECMO.

• Journal of Chest Surgery
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• v.28 no.10
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• pp.885-891
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• 1995

In order to test the hypothesis that the pulmonic valve, when used to replace the aortic root as a pulmonary autograft, will remain a viable anatomical structure and will grow and develop normally along with the host, we performed aortic valve replacement with the pulmonary autograft in 15 neonatal piglets. The weight of the donor was 9.3 $\pm$ 0.2 kg, the recipient 9.6 $\pm$ 0.3 kg. Measured diameters of pulmonic annulus were 14 $\pm$ 0.2 mm for autograft and 14.2 $\pm$ 0.2 mm for pulmonary artery homograft. Operation was performed under cardiopulmonary bypass with deep hypothermia [20oC at low flow perfusion [70 ml/kg/min . The mean operation time was 227 $\pm$ 10 min., bypass time 152$\pm$ 7.6 min. and aortic cross clamp time 73$\pm$ 4.6 min.. 9 piglets survived more than 12 hours. One survived 12 days and died of pneumonia and the latest one survived in good condition and sacrificed at postoperative 6th week for cardiac catheterization and pathologic examination that revealed the viability and growing of the pulmonary autograft. Currently we are able to complete the operation with good preservation of cardiac function, and our postoperative care has evolved to the extent that we are now confident enough of having an acceptable percentage of long term survivors to undertake a definite study in this regard.

• Progress in Medical Physics
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• v.22 no.4
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• pp.172-177
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• 2011

The purpose of this study was to analyze $^{68}Ga$-BAPEN dynamic PET image in rat myocardium to evaluate potential of this radiotracer as a perfusion imaging agent. Animal PET/CT scan was done in 9 rats during 120 minutes. Especially we synthesized $^{68}Ga$-BAPEN with kit which is simple and low cost method. PET images showed the in vivo dynamic distribution of $^{68}Ga$-BAPEN in the chest region of rats. Initially $^{68}Ga$-BAPEN PET images showed aorta and liver activities and a few minutes later, $^{68}Ga$-BAPEN moved to myocardium. Regions of interest were drawn on myocardium, liver, lung and blood pool. Time-activity curves showed significant uptake of $^{68}Ga$-BAPEN in myocardium. The contrast ratios of myocardial to blood pool, lung and liver at 60 minutes after injection were 1.66, 2.82 and 0.60. To estimate accurate kinetic parameters, 60 minutes after injection was required to PET scan as myocardium image contrast ratios reached to constant values. As a result, $^{68}Ga$-BAPEN would be suitable radiotracer for PET which can applied to diagnosis of myocardial perfusion diseases after further preclinical and clinical investigations.

• Journal of Chest Surgery
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• v.37 no.11
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• pp.903-910
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• 2004

Background: The total aortic arch replacement is one of the most difficult operations with high mortality rate. But the arch first technique with subclavian arterial perfusion has been reported to be a safe methods for arch replacement. Material and Method: Between Feb 2003 and July 2004, 18 patients, 10 men and 8 women, underwent total aortic arch replacement with arch first technique. Their mean age was $59.3\pm12.9$ years. The patietns received 11 acute aortic dissections, 3 chronic aortic dissectiong aneurysms, and 4 ruptured aortic arch aneurysms. Result The mean admission period was $20.2\pm7.4$ days. There was one early mortality case which died of low cardiac output syndrome and another late mortality case which died of cerebral hemorrhage. The others were discharged without any sequelae and they were followed up for an average period of $180\pm156.3$ days. Conclusion: The total aortic arch replacement with arch first technique and subclavian arterial perfusion is a good method that will reduce the surgical mortality and the possibility of secondary late reoperation from the remnant distal aortic problems.