• ETRI Journal
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• v.39 no.5
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• pp.662-671
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• 2017

Coronary artery disease (CAD) is a major cause of death in the world. As a non-invasive imaging modality, computed tomography angiography (CTA) is now usually used in clinical practice for CAD diagnosis. Precise quantification of coronary stenosis is of great interest for diagnosis and treatment planning. In this paper, a novel cluster method based on a Modified Student's t-Mixture Model is applied to separate the region of vessel lumen from other tissues. Then, the area of the vessel lumen in each slice is computed and the estimated value of it is fitted with a curve. Finally, the location and the level of the most stenoses are captured by comparing the calculated and fitted areas of the vessel. The proposed method has been applied to 17 clinical CTA datasets and the results have been compared with reference standard degrees of stenosis defined by an expert. The results of the experiment indicate that the proposed method can accurately quantify the stenosis of the coronary artery in CTA.

• Journal of Korean Clinical Nursing Research
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• v.15 no.1
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• pp.19-28
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• 2009

Purpose: The purpose of this study was to examine the effect of position change on discomfort and bleeding in patients undergone coronary angiography with a vascular device and required bed-rest. Method: This study utilized nonequivalent control group non-synchronized design. Data were collected from 118 inpatients after coronary angiography and stayed in general ward at Y hospital in Seoul, from June 5 to August 12, 2008. After coronary angiography, position change was performed to the experimental group who consisted of 59 patients. They stayed in supine position just after angiography and then head-up position with 15 degrees was applied 1 hour later. After that, they could change the position alternatively into lateral position with leg down and supine position. The control group was positioned keeping the affected leg immobile with supine position for 4 hours. Results: The experimental group reported significantly more comfortable than control group after position change. There were no significant differences in the grades of bleeding or hematoma at puncture site between the two groups. Conclusion: The position change in patients undergone angiography could be applied without any harm such as bleeding or hematoma, but effective in reducing back pain and subjective patients' discomforts.

• Journal of Chest Surgery
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• v.40 no.11
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• pp.773-776
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• 2007

A 47-year-old male with hypertension, diabetes mellitus and heavy smoking, but no anginal symptoms, presented with claudication of the lower extremities. Extremity angiography with coronary angiography revealed peripheral arterial lesions including a left subclavian artery occlusion with coronary artery disease. The patient underwent an initial off-pump coronary artery bypass with an ascending aorto-axillary bypass. The right internal mammary artery was anastomosed to the left anterior descending coronary artery. The greater saphenous vein graft was connected from the ascending aorto-axillary bypass graft to the diagonal branch. At postoperative day 18, femorofemoral and bilateral femoropopliteal bypasses were performed. We report a case of the combined repair of coronary artery disease and a left subclavian artery occlusion.

• Korean Journal of Radiology
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• v.22 no.11
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• pp.1749-1763
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• 2021

Coronary computed tomography angiography (CCTA) is routinely used for anatomical assessment of coronary artery disease (CAD). However, invasive measurement of fractional flow reserve (FFR) is the current gold standard for the diagnosis of hemodynamically significant CAD. CT-derived FFRCT and CT perfusion are two emerging techniques that can provide a functional assessment of CAD for risk stratification and clinical decision making. Several clinical studies have shown that the diagnostic performance of concomitant CCTA and functional CT assessment for detecting hemodynamically significant CAD is at least non-inferior to that of other routinely used imaging modalities. This article aims to review the current clinical evidence and recent developments in functional CT techniques.

• The Korean Journal of Nuclear Medicine
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• v.27 no.1
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• pp.51-58
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• 1993

We have anlayzed the polar maps of dipyridamole stress/rest $^{99m}Tc$-MIBI SPECT and compared the quantitated perfusion defects of dipyridamole stress polar map and the findings of coronary angiography in 56 pateints with coronary artery diseases. We performed the same day dipyridamole stress-rest myocardial SPECT, reconstructed the polar maps according to Cedars-Sinai method and quantitated perfusion detects of total myocardium and the territory of each artery, comparing the polar maps of patients with normal files. Stenosis more than 50 percent was considered significant and myocardial ischemic score was calculated as summed score of percents of main coronary arteries. Positive concordance of myocardial SPECT with coronary angiography were 82.6% with left anterior descending artery (LAD), 85.7% with left circumflex artery (LCx) and 78.6% with right coronary artery (RCA). Perfusion defect of SPECT polar map and the stenosis of coronary artery showed the contingency phi of 0.55 (p<0.0001) with total atreries, 0.38 (p = 0.016) with LAD, 0.50 (p<0.0001) with LCx and 0.40 (p = 0.007) with RCA. Dipyridamole stress percent defect of polar map was correlated with myocardial ischemic score with Spearman's rho of 0.47 (p = 0.001) in total arteries, 0.48 (p=0.001) in LAD, 0.56 (p < 0.001) in LCx and 0.38 (p=0.002) in RCA. These findings revealed that defect of the dipyridamole stress myocardial $^{99m}Tc$-MIBI SPECT and the percent extent of this defect were related with significant artery stenosis of individual arteries and the degree of stenosis. We thought that we could use the defects in the polar map of dipyridamole stress $^{99m}Tc$-MIBI SPECT for the quantification of myocardiasl perfusion decrease.

• Korean Circulation Journal
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• v.48 no.12
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• pp.1131-1134
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• 2018

• Journal of Chest Surgery
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• v.35 no.3
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• pp.182-187
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• 2002

Background: There have been many reports of coronary angiographic findings after coronary bypass grafting, most of which are focused on the graft patency rate of the bypass conduits. However, postoperative angiography can provide numerous informations other than patency rates that are useful for establishing operative strategy. Material and Method: We studied 73 patients in whom coronary angiography was done after more than 1 month of CABG. Mean interval from the operation to coronary angiography was 10.6 months and the reasons for coronary angiography follow up were residual or recurrent angina in 54 patients, abnormalities on myocardial perfusion scan or echocardiography in 13 patients, and for simple follow up in 6 patients. Result: Overall graft patency rate was 80.9% (internal thoracic artery 100%, saphenous vein 75.0%) in patients of simple follow up and 61.6%(internal thoracic artery 81.1%, saphenous vein 55.3%) in patients with ischemia. Progression of native coronary arterial disease proximal to the grafting site was found in 50 patients(68.5%). Among 201 coronary arterial branches that had not been completely occluded preoperatively, ninty five branches(47.3%) revealed progression of diameter stenosis by more than 20% on the follow up study. Among them, 64 branches(31.8%) progressed to total occlusion. The incidence of disease progression was highter in the coronary arteries with patent grafts(57.5%) than in those with occluded grafts(36.3%)(p<0.05), Comparing internal thoracic artery graft with saphenous vein graft, internal thoracic artery was superior to saphenous vein, not only in terms of patency(83.3% vs 56.6%), but also in terms of result of later percutaneous intervention success rate(100% vs 62%, p<0.05). Conclusion: Due to the considerable incidence of progression of native coronary artery stenosis in the early postoperative periods, bypass grafting of a vessel with borderline stenosis, especially with vein graft, must be done prudently. And it was confirmed again that revascularization of left anterior descending artery is most important and that internal thoracic artery was superior to saphenous vein.

• Journal of the Korean Society of Radiology
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• v.14 no.2
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• pp.111-120
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• 2020

Research should be actively conducted for the ability of X-ray equipment and Retrospective image analysis of X-ray equipment used in hospitals. Retrospective image analysis of X-ray machines, CT and MRI of radiology and medical equipment has been actively conducted. However, image quality measurement using angiography equipment of angiography room is mostly measured with phantom, and image quality measurement on image after being taken by actual patient is insufficient and researches on accurate image quality measurement method are remarkable. It is in short supply. Therefore, through this study, the researcher devised a method to measure the image quality of the acquired image after coronary angiography, and to provide a high quality image to the operator. The equipment and programs used were angiographic examination equipment (Axiom Artis Zee Ceiling) and Image J program. Subjects were images automatically saved in PACS program after coronary angiography.For image quality measurement, selected the AP Caudal 30° image that show the LCA vessel well and the LAO 30° image that show the RCA vessel well during the coronary angiography. In order to measure the background and ROI of the selected image by selecting an image, a criterion on how to find and measure a section where the overlap of the shadow, such as blood vessel, liver and lung is minimized, is presented. In conclusion, there is no exact standard for analyzing an image quality measurement method of angiography image. Therefore, in order to provide quality images to the practistioners, not only the technicians of the equipment but also the users who actually use them should become researchers and conduct research on image quality measurement in various ways. Thus, it is expected to provide excellent images to patients.

• Journal of The Korean Society of Integrative Medicine
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• v.8 no.1
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• pp.125-135
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• 2020

Purpose : Obesity indices are major predictive markers for coronary artery stenosis, but there are few studies about the relationship between obesity indices and coronary artery stenosis in the Korean population. Therefore, we analyzed the association between obesity indices and coronary artery stenosis among health-screen examinees. Methods : This study included 99 males and females who visited a health-examination center. The obesity indices included body mass index (BMI), waist circumference (WC), visceral adipose tissue (VAT), visceral adipose tissue/subcutaneous adipose tissue ratio (V/S ratio). All subjects had their degree of coronary artery stenosis measured using coronary computed tomography angiography (CCTA). A multiple logistic regression test was conducted to analyze the association between obesity indices and coronary artery stenosis. Results : This study was taken by multiple logistic regression test adjusted by age, sex, smoking status, frequency of alcohol drinking/week and frequency of exercise/week. The adjusted odds ratio for the presence of coronary artery stenosis for subjects with abdominal obesity (abdominal obesity defined as a waist circumference ≥ 90 cm in males; ≥ 85 cm in females) was 6.263 (95 % confidence interval (CI) 1.974-19.869), for subjects with visceral obesity by visceral adipose tissue (visceral obesity defined as a visceral adipose tissue ≥ 100) was 11.430 (95 % CI 3.044-42.928). Conclusion : In this study of adults, WC and VAT were independent predictors of coronary artery stenosis. These results suggest that WC and VAT may be useful markers of coronary artery stenosis.

• The Korean Journal of Nuclear Medicine
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• v.25 no.2
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• pp.165-176
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• 1991

The purpose of this study was to assess the ability of quantitative Tl-201 tomography to identify and localize coronary artery disease (CAD). The study population consisted of 41 patients (31 males, 10 females; mean age $55{\pm}7$ yr) including 14 with prior myocardial infarction who underwent both exercise Tl-201 myocardium SPECT and coronary angiography for the evaluation of chest pain. From the short axis and vertical long axis tomograms, stress extent polar maps were generated by Cedars-Sinai Medical Center program, and the % stress defect extent (SDE) was quantified for each coronary artery territory. For the purpose of this study, the coronary circulation was divided into 6 arterial segments, and the "myocardial ischemic score" (MIS) was calculated from the coronary angiogram. Sensitivity for the detection of CAD ($\geq50%$ coronary stenosis by angiography) by angiography) by stress extent polar map was 95% in single vessel disease, and 100% in double and triple vessel deseases. Overall sensitivity was 97%. Sensitivity and specificity for the detection of individual diseased vessels were, respectively, 87% and 90% for the left anterior descending artery (LAD), 36% and 93% for the left circumflex artery (LCX), and 71% and 70% for the right coronary artery (RCA). Concordance for the detection of individual diseased vessels between the coronary angiography and stress polar map was fair for the LAD (kappa=0.70), and RCA (kappa=0.41) lesions, whereas it was poor for the LCX lesions (kappa : 0.32). There were siginificant correlations between the MIS and SDE in LAD (rs=0.56, p=0.0027), and RCA territory (rs=0.60, p=0.0094). No significant correlation was found in LCX territory. When total vascular territories were combined, there was a significant correlation between the MIS and SDE (rs=0.42, p=0.0116). In conclusion, the quantitative analysis of Tl-201 tomograms appears to be accurate for determining the presence and location of CAD.