• Journal of the Korean Society of Radiology
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• v.13 no.5
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• pp.713-720
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• 2019

The purpose of this study was to propose a new measurement method for accurate measurement of vessel diameter in computed tomography angiography(CTA). CTA test was performed after non-ionic iodine contrast agent was flowed at a constant rate to self-maded perfusion phantom. After obtaining raw data, images were reconstructed with multi-planar reconstruction(MPR) and maximal intensity projection(MIP). Diameters of vascular models were measured for each technique. Relative and conventional measurements were then compared. The mean diameter of the vascular model was closer to the actual measurement when relative measurement was used compared to that when conventional measurement was used both in MPR and MIP. Relative measurements of MPR and MIP were closer to actual measurement than those of conventional measurement (34% VS, 24%, p<0.05). The relative measurement method proposed in this study was closer to the actual measurement than the conventional measurement method. However, both test methods were still larger than actual results. Therefore, further study of relative measurement method is needed using this study as basic data.

• Applied Chemistry for Engineering
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• v.33 no.5
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• pp.545-550
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• 2022

As a result of the rapid entry into an aging society and westernized eating habits, the number of heart disease patients caused by angina pectoris, myocardial infarction, and high blood pressure has increased by more than 100,000 over five years. Heart disease has consistently ranked second in the cause of death in Korea over the past eight years, and medical expenses consumed annually reach 6 trillion won. While various treatments are being proposed for more patients, drug-coated balloon catheters have been developed and gradually commercialized to solve the disadvantages of stent implantation such as restenosis and increased risk of bleeding due to long-term double antiplatelet medication. In Korea, it began to use a drug-coated balloon catheter with the first release of it called "SeQuent Please^Ⓡ (Bibrown Korea)" in 2010. Its demand increased gradually as insurance benefits were applied in 2012. Drug-coated balloon angioplasty is increasing in use not only in Korea but also around the world, especially in the Asia-Pacific region, including Japan. Until now, the demand for domestic products is increasing, and if the efficiency in vivo and clinical trials is proven in the future, it is expected to be an effective procedure compared to high-risk stent implantation.

• The Journal of Internal Korean Medicine
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• v.44 no.3
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• pp.387-401
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• 2023

Objective: This study was conducted to investigate the preventive effect of herbal medicines on restenosis after percutaneous coronary intervention (PCI) by reviewing randomized controlled trials (RCTs). Methods: RCTs were searched for herbal medicine treatment after PCI using eight online databases (PubMed, CNKI, Wanfang, J-STAGE, OASIS, ScienceON, KTKP, and KISS). Studies that confirmed restenosis through coronary angiography at follow-up were selected according to the inclusion and exclusion criteria. The primary outcome was the restenosis rate, and the secondary outcome was the angina recurrence rate. Data were extracted from the final selected studies according to the research methodology and then analyzed with Review Manager 5.4.1. Study quality was assessed using Cochrane's risk-of-bias (RoB) tool. Results: Of the 252 papers obtained through the primary search, nine studies that met the selection criteria were finally selected. In these nine studies, herbal medicine combined with western medicine was used for the experimental group, and western medicine treatment was used alone for the control group. The meta-analysis result revealed that the restenosis rate and angina recurrence rate were significantly lower in the experimental group than in the control group (RR=0.34, 95% CI: 0.22-0.53, p<0.00001, I²=0% and RR=0.47, 95% CI: 0.29-0.78, p=0.004, I²=0%, respectively). Furthermore, the quality of studies assessed by Cochrane's RoB was low. Conclusions: This study showed that the combined treatment of herbal medicine and western medicine was effective in preventing restenosis and angina after PCI. As the number of papers included in this study was small, a large number of high-quality clinical studies should be considered in the future.

• The Korean Journal of Nuclear Medicine
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• v.38 no.6
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• pp.486-491
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• 2004

Purpose: factor analysis and independent component analysis (ICA) has been used for handling dynamic image sequences. Theoretical advantages of a newly suggested ICA method, ensemble ICA, leaded us to consider applying this method to the analysis of dynamic myocardial $H_2^{15}O$ PET data. In this study, we quantified patients' blood flow using the ensemble ICA method. Materials and Methods: Twenty subjects underwent $H_2^{15}O$ PET scans using ECAT EXACT 47 scanner and myocardial perfusion SPECT using Vertex scanner. After transmission scanning, dynamic emission scans were initiated simultaneously with the injection of $555{\sim}740$ MBq $H_2^{15}O$. Hidden independent components can be extracted from the observed mixed data (PET image) by means of ICA algorithms. Ensemble learning is a variational Bayesian method that provides an analytical approximation to the parameter posterior using a tractable distribution. Variational approximation forms a lower bound on the ensemble likelihood and the maximization of the lower bound is achieved through minimizing the Kullback-Leibler divergence between the true posterior and the variational posterior. In this study, posterior pdf was approximated by a rectified Gaussian distribution to incorporate non-negativity constraint, which is suitable to dynamic images in nuclear medicine. Blood flow was measured in 9 regions - apex, four areas in mid wall, and four areas in base wall. Myocardial perfusion SPECT score and angiography results were compared with the regional blood flow. Results: Major cardiac components were separated successfully by the ensemble ICA method and blood flow could be estimated in 15 among 20 patients. Mean myocardial blood flow was $1.2{\pm}0.40$ ml/min/g in rest, $1.85{\pm}1.12$ ml/min/g in stress state. Blood flow values obtained by an operator in two different occasion were highly correlated (r=0.99). In myocardium component image, the image contrast between left ventricle and myocardium was 1:2.7 in average. Perfusion reserve was significantly different between the regions with and without stenosis detected by the coronary angiography (P<0.01). In 66 segment with stenosis confirmed by angiography, the segments with reversible perfusion decrease in perfusion SPECT showed lower perfusion reserve values in $H_2^{15}O$ PET. Conclusions: Myocardial blood flow could be estimated using an ICA method with ensemble learning. We suggest that the ensemble ICA incorporating non-negative constraint is a feasible method to handle dynamic image sequence obtained by the nuclear medicine techniques.

• Journal of Chest Surgery
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• v.31 no.8
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• pp.739-748
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• 1998

Background: It has been well documented that transient occlusion of the coronary artery causes myocardial ischemia and finally cell death when ischemia is sustained for more than 20 minutes. Extensive studies have revealed that ischemic myocardium cannot recover without reperfusion by adequate restoration of blood flow, however, reperfusion can cause long-lasting cardiac dysfunction and aggravation of structural damage. The author therefore attempted to examine the effect of postischemic reperfusion on myocardial ultrastructure and to determine the rationales for recanalization therapy to salvage ischemic myocardium. Materials and methods: Young Holstein-Friesian cows(130∼140 Kg body weight; n=40) of both sexes, maintained with nutritionally balanced diet and under constant conditions, were used. The left anterior descending coronary artery(LAD) was occluded by ligation with 4-0 silk snare for 20 minutes and recanalized by release of the ligation under continuous intravenous drip anesthesia with sodium pentobarbital(0.15 mg/Kg/min). Drill biopsies of the risk area (antero-lateral wall) were performed at just on reperfusion(5 minutes), 1-, 2-, 3-, 6-, 12-hours after recanalization, and at 1-hour assist(only with mechanical respiration and fluid replacement) after 12-hour recanalization. The materials were subdivided into subepicardial and subendocardial tissues. Tissue samples were examined with a transmission electron microscope (Philips EM 300) at the accelerating voltage of 60 KeV. Results: After a 20-minute ligation of the LAD, myocytes showed slight to moderate degree of ultrastructural changes including subsarcolemmal bleb formation, loss of nuclear matrix, clumping of chromatin and margination, mitochondrial destruction, and contracture of sarcomeres. However, microvascular structures were relatively well preserved. After 1-hour reperfusion, nuclear and mitochondrial matrices reappeared and intravascular plugging by polymorphonuclear leukocytes or platelets was observed. However, nucleoli and intramitochondrial granules reappeared within 3 hours of reperfusion and a large number of myocytes were recovered progressively within 6 hours of reperfusion. Recovery was apparent in the subepicardial myocytes and there were no distinct changes in the ultrastructure except narrowed lumen of the microvessels in the later period of reperfusion. Conclusions: It is likely that the ischemic myocardium could not be salvaged without adequate restoration of coronary flow and that the microvasculature is more resistant to reversible period of ischemia than subendocardium and subepicardium. Therefore, thrombolysis and/or angioplasty may be a rational method of therapy for coronarogenic myocardial ischemia. However, it may take a relatively longer period of time to recover from ischemic insult and reperfusion injury should be considered.

• Journal of Chest Surgery
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• v.31 no.12
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• pp.1183-1194
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• 1998

Background: From Sept. 1985 to Sept. 1997, 2,000 cases of open heart surgery(OHS) were performed in the Department of Thoracic & Cardiovascular Surgery, Pusan Paik Hospital, College of Medicine, Inje University. Material and Method: Among the total of 2,000 cases of OHS, 1532 cases were congenital heart disease(CHD) and 468 cases were acquired heart disease(AHD). The age distribution was 9 days(4.0kg) to 68 years in CHD and 11 to 66 years in AHD. In 1532 cases of CHD, there were 1403 acyanotic cases and 129 cyanotic cases. Result: The CHD cases consisted of 940 ventricular septal defects(61.4%), 324 atrial septal defects(21.1%), 112 tetralogy of Fallot(7.3%), 46 pulmonary stenosis(3%), 38 endocardial cushion defects(2.5%), 15 valsalva sinus ruptures(1%), 4 transposition of great arteries (0.3%), 4 double outlet right ventricles(0.3%), and etc. Corrective operations were applied for congenital heart disease with a result of 3.1% hospital mortality. Of 468 AHD, 381 cases were valvular heart diseases, 48 ischemic heart diseases, 12 cardiac tumors, 8 annuloaortic ectasias, 16 dissecting aortic aneurysms and etc. In the 381 valvular heart diseases, there were 226 single valve replacements(36 aortic valve replacements(AVR), 188 mitral valve replacements(MVR), and 2 tricuspid valve replacements(TVR), among these were 71 cases of double valve replacements(AVR & MVR), 54 cases of MVR with tricuspid valve annuloplasty(TVA), and 18 cases of AVR, MVR with TVA. The total implanted prosthetic valves were 466. In MVR, 123 St. Jude Medical valves, 90 Carpentier-Edwards valves, 65 CarboMedics valves, 42 Sorin valves and 16 other valves were used. In AVR, 68 St. Jude Medical valves, 36 CarboMedics valves, 14 Carpentier-Edwards valves and 9 other valves were used. Coronary Artery Bypass Surgery(CABG) were performed in 48 cases. The patterns of bypass graft were 14 patients of single vessel graft, 21 patients of two vessels graft, 10 patients of three vessels graft and 3 patients of four vessels graft. Conclusion: The hospital operation mortality rate of congenital acyanotic, cyanotic and acquired heart diseases were 2.0%, 15.5%, and 5.1% respectively. The overall mortality rate was 3.6%(72/2,000).

• Journal of Chest Surgery
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• v.33 no.7
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• pp.547-551
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• 2000

Background; The purpose of this study was to analyze the early and midterm results of Cabrol technique to assist in making future decisions on a more adequate technique for repairing aortic root diseases. Material and Method; From August 1993 to July 1999, we performed Cabrol technique in 18 patients ; 12 annuloaortic ectasia, 6 Stanford type A aortic dissection. Male and female ratio was 11;7, mean age was 46.9$\pm$12.3 years and mean follow up period was 22.5$\pm$21.5 months. We analysed the factors influencing postoperative complications and early mortality. The factors were old age(>60 years), high NYHA(>III), preoporative concomitant disease, urgency of operation, concomitant procedure, long pump preoperative concomitant disease, urgency of operation, concomitant procedure, long pump time(>200 minute), and hospital stay time (>30 days). Result; Operative mortality was 11.1%, late mortality was 11.1%, and overall mortality was 22.2%. The causes of operative death were a heart failure and an arrhythmia. The causes of late death were an acute myocardial infarction and an unknown etiology. Postoperative complications were bleeding, wound infection, toxic hepatitis, acute renal failure, and cerebral infarction. The factors influencing postoperative complications were hihg MYHA Fc(>III) (p=0.044), concomitant disease (p=0.044), long pump time(>200 minute)(p=0.015), and concomitant procedure(p=0.004). There were no significant factors influencing early mortality. Conclusion; The lower postoperative bleeding rate and no complication related to tension of anastomosis after Cabrol technique warrant its consideration in patients requiring aortic root replacement, especially without feasible mobilization of coronary arteries. However, to confirm the graft thrombosis, a more detailed study including periodic angiography will be required.

• Progress in Medical Physics
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• v.10 no.1
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• pp.1-7
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• 1999

In this study, the dose distributions of a $^{32}$ p uniform cylindrical volume source and a surface source, a pure $\beta$emitter, were calculated in order to obtain information relevant to the utilization of a balloon catheter and a radioactive stent. The dose distributions of $^{32}$ p were calculated by means of the EGS4 code system. The sources are considered to be distributed uniformly in the volume and on the surface in the form of a cylinder with a radius of 1.5 mm and length of 20 mm. The energy of $\beta$particles emitted is chosen at random in the $\beta$ energy spectrum evaluated by the solution of the Dirac equation for the Coulomb potential. Liquid water is used to simulate the particle transport in the human body. The dose rates in a target at a 0.5mm radial distance from the surface of cylindrical volume and surface source are 12.133 cGy/s per GBq (0.449 cGy/s per mCi, uncertainty: 1.51%) and 24.732 cGy/s per GBq (0.915 cGy/s per mCi, uncertainty: 1.01%), respectively. The dose rates in the two sources decrease with distance in both radial and axial direction. On the basis of the above results, the determined initial activities were 29.69 mCi and 1.2278 $\mu$Ci for the balloon catheter and the radioactive stent using $^{32}$ P isotope, respectively. The total absorbed dose for optimal therapeutic regimen is considered to be 20 Gy and the treatment time in the case of the balloon catheter is less than 3 min. Absorbed doses in targets placed in a radial direction for the two sources were also calculated when it expressed initial activity in a 1 mCi/ml volume activity density for the cylindrical volume source and a 0.1 mCi/cm$^2$ area activity density for the surface source. The absorbed dose distribution around the $^{32}$ P cylindrical source with different size can be easily calculated using our results when the volume activity density and area activity density for the source are known.

• Journal of Chest Surgery
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• v.41 no.2
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• pp.216-222
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• 2008

Background: Prosthetic annuloplasty rings are used for the reconstruction of the mitral valve annulus. However, there is controversy over the best ring to use for reconstruction. In this study, we evaluated the long term result of using a Teflon felt strip as an alternative to commercial rings. Material and Method: From 1996 to 2007, we enrolled 47 patients with pure mitral regurgitation greater than grade III. All patients had an ejection fraction of 40% or more. Patients with congenital heart disease or other valvular heart disease were excluded from this study. They were divided into two groups; the commercial ring group (Group CR) and the Teflon felt ring group (Group TF). Result: There was no mortality. The postoperative echocardiography showed no significant change in the overall ejection fraction (from $58.0{\pm}11.2%\;to\;42.8{\pm}8.4%$). There were no significant differences between the two groups with regard to morbidity, the reoperation rate and recurrence of mitral regurgitation greater than grade II. Conclusion: The long term results from this study showed that posterior mitral annuloplasty using Teflon felt had similar results compared to annuloplasty using commercial rings.