• Journal of the Korean Society of Radiology
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• v.83 no.1
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• pp.42-53
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• 2022

The clinical concept of coronary artery disease (CAD) has seen a paradigm shift over the last decade. CAD is mostly a progressive disease, and patients with CAD can develop acute coronary syndromes at any point in disease progression. In this clinical context, a new term, "chronic coronary syndrome," was published in the 2019 European Society of Cardiology guidelines, reflecting the importance of early diagnosis and active management. Recent advances have been made in the evaluation of CAD using coronary CT angiography (CCTA). The clinical usefulness of CCTA in patients with stable angina or chronic coronary syndrome begins with the detection of early asymptomatic CAD. The characterization of atherosclerotic plaque and its role in determining treatment strategies for CAD have been demonstrated for all stages of the disease. This review describes the pathophysiology of stable angina to aid in the understanding of the clinical applications of CCTA.

• Journal of radiological science and technology
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• v.37 no.4
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• pp.307-313
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• 2014

The purpose of this study is that in coronary artery angiography computed tomography (coronary CTA), to gain high quality of image and to use low dose radiation by administrating normal saline and converting the mode of scanning heart rate (HR) characteristics before infusing contrast media. All patients data (total specimens: 200, male: 108, female: 92) were measured by using appropriate mode of scanning the heart rate (HR) after injection of saline. in addition we measured radiation dose (CTDIvol, effective dose) in all examinations. CT number and noise, and blurring of coronary artery (proximal RCA, middle RCA, proximal LCA) were measured and compared. The result of this study after injection of saline, mean heart rate was decreased about $4.8{\pm}0.3bpm$ (beats per minute). 33 patients (13%) got converting scan mode due to reducing heart rate (HR). In prospective gating mode, radiation dose were measured less $6.0{\pm}1.0mSv$ (54.1%) than retrospective gating mode. Also showed a significant difference in heart rate decrease in image evaluation.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.9 no.2
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• pp.196-204
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• 2016

World Health Organization reported that heart-related diseases such as coronary artery stenoses show the highest occurrence rate which may cause heart attack. Using Computed Tomography angiography images will allow radiologists to detect and have intervention by creating 3D roadmapping of the vessels. However, it is often complex and difficult do reconstruct 3D vessel which causes very large amount of time and previous researches were studied to segment vessels more accurate automatically. Therefore, in this paper, Region Competition, Geodesic Active Contour (GAC), Multi-atlas based segmentation and Active Shape Model algorithms were applied to segment aortic root from CTA images and the results were analyzed by using mean Hausdorff distance, volume to volume measure, computational time, user-interaction and coronary ostium detection rate. As a result, Extracted 3D aortic model using GAC showed the highest accuracy but also showed highest user-interaction results. Therefore, it is important to improve automatic segmentation algorithm in future

• Journal of radiological science and technology
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• v.39 no.4
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• pp.535-541
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• 2016

This study aimed to identify dose reduction measures by retrospectively analyzing the entrance surface dose at computed tomography and angiography in cardiovascular examination and to contribute the patients with renal impairmend and a high probability of side effects to determine the inspection's direction by measuring the contrast usages actually to active actions for the dose by actually measuring the contrast medium dose. The CTDIvol value and air kerma value, which are the entrance surface doses of the two examinations, and the contrast medium dose depending on the number of slides were compared and analyzed. This study was conducted in 21 subjects (11 males; 10 females) who underwent Cardiac Computed Tomographic Angiography (CCTA) and Coronary Angiography (CAG) in this hospital during the period from May 2014 to May 2016. The subject's age was 48~85 years old (mean $65{\pm}10$ years old), and the weight was 37.6~83.3 kg (mean $63{\pm}6kg$). Dose reduction could be expected in the cardiovascular examination using CCTA rather than in the examination using CAG. In terms of contrast medium dose, CAG used a smaller dose than CCTA. In particular, as the number of slides increases at CAG, the contrast medium dose increases. Therefore, in order to reduce the contrast medium dose, the number of slides suitable for the scan range must be selected.

• Journal of Chest Surgery
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• v.54 no.2
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• pp.146-149
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• 2021

Coronary artery bypass grafting (CABG) is rarely performed in infants because of its technical difficulty and unclear long-term results. A 90-day-old male infant weighing 3.5 kg who underwent an arterial switch operation (ASO) for transposition of the great arteries developed left coronary artery insufficiency despite augmentation and reimplantation of the left coronary button. On-pump beating heart CABG was performed using an internal mammary artery graft to revascularize the left anterior descending artery. Postoperative computed tomography angiography revealed that the graft was patent. At 7 months postoperatively, the patient weighed 8.5 kg, and echocardiography revealed good ventricular function. CABG can be an alternative treatment for post-ASO coronary complications in early infancy.

• Korean Journal of Radiology
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• v.21 no.12
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• pp.1305-1316
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• 2020

In approximately 10% of patients with acute myocardial infarction (MI), angiography does not reveal an obstructive coronary stenosis. This is known as myocardial infarction with non-obstructive coronary arteries (MINOCA), which has complex and multifactorial causes. However, this term can be confusing and open to dual interpretation, because MINOCA is also used to describe patients with acute myocardial injury caused by ischemia-related myocardial necrosis. Therefore, with regards to this specific context of MINOCA, the generic term for MINOCA should be replaced with troponin-positive with non-obstructive coronary arteries (TpNOCA). The causes of TpNOCA can be subcategorized into epicardial coronary (causes of MINOCA), myocardial, and extracardiac disorders. Cardiac magnetic resonance imaging can confirm MI and differentiate various myocardial causes, while cardiac computed tomography is useful to diagnose the extracardiac causes.

• Korean Journal of Radiology
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• v.21 no.9
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• pp.1055-1064
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• 2020

Objective: To assess the incremental prognostic value of coronary computed tomography angiography (CCTA) in comparison to a clinical risk model (Framingham risk score, FRS) and coronary artery calcium score (CACS) for future cardiac events in ischemic stroke patients without chest pain. Materials and Methods: This retrospective study included 1418 patients with acute stroke who had no previous cardiac disease and underwent CCTA, including CACS. Stenosis degree and plaque types (high-risk, non-calcified, mixed, or calcified plaques) were assessed as CCTA variables. High-risk plaque was defined when at least two of the following characteristics were observed: low-density plaque, positive remodeling, spotty calcification, or napkin-ring sign. We compared the incremental prognostic value of CCTA for major adverse cardiovascular events (MACE) over CACS and FRS. Results: The prevalence of any plaque and obstructive coronary artery disease (CAD) (stenosis ≥ 50%) were 70.7% and 30.2%, respectively. During the median follow-up period of 48 months, 108 patients (7.6%) experienced MACE. Increasing FRS, CACS, and stenosis degree were positively associated with MACE (all p < 0.05). Patients with high-risk plaque type showed the highest incidence of MACE, followed by non-calcified, mixed, and calcified plaque, respectively (log-rank p < 0.001). Among the prediction models for MACE, adding stenosis degree to FRS showed better discrimination and risk reclassification compared to FRS or the FRS + CACS model (all p < 0.05). Furthermore, incorporating plaque type in the prediction model significantly improved reclassification (integrated discrimination improvement, 0.08; p = 0.023) and showed the highest discrimination index (C-statistics, 0.85). However, the addition of CACS on CCTA with FRS did not add to the prediction ability for MACE (p > 0.05). Conclusion: Assessment of stenosis degree and plaque type using CCTA provided additional prognostic value over CACS and FRS to risk stratify stroke patients without prior history of CAD better.

• Journal of Yeungnam Medical Science
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• v.29 no.1
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• pp.61-64
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• 2012

The left aortic arch with an aberrant right subclavian artery, or arteria lusoria, is the most common aortic arch anomaly, occurring in 0.5-2.5% of individuals. In such cases, the angular course of the arteria lusoria to the ascending aorta imposes difficulty in passing a guide wire to the ascending aorta during right transradial catheterization. Here, the case of a 53-year-old woman with intermittent chest tightness and coughing is reported. Aberrant right subclavian artery (arteria lusoria) was diagnosed via aortogram during right transradial coronary angiography. Compression of the esophagus and trachea by the aberrant right subclavian artery was demonstrated by chest computed tomography (CT).

• Journal of Chest Surgery
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• v.45 no.4
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• pp.251-253
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• 2012

We report a redo coronary artery bypass grafting (CABG) in a 55-year-old man. Angina recurred 7 years after the initial surgery. Coronary angiography showed all patent grafts except a faint visualization of the in situ right gastroepiploic artery (RGEA) graft, which was anastomosed to the posterior descending coronary artery, associated with celiac axis stenosis. Redo-CABG was performed at postoperative 10 years because of aggravated angina and decreased perfusion of the inferior wall in the myocardial single photon emission computed tomography. The saphenous vein graft was interposed between the 2 in situ grafts used previously; the right internal thoracic artery and RGEA grafts. Angina was relieved and myocardial perfusion was improved.

• Korean Journal of Radiology
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• v.24 no.11
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• pp.1081-1092
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• 2023

Objective: To investigate the incidence of microvascular myocardial ischemia in diabetic patients without obstructive coronary artery disease (CAD) and its relationship with angina. Materials and Methods: Diabetic patients and an intermediate-to-high pretest probability of CAD were prospectively enrolled. Non-diabetic patients but with an intermediate-to-high pretest probability of CAD were retrospectively included as controls. The patients underwent dynamic computed tomography-myocardial perfusion imaging (CT-MPI) and coronary computed tomography angiography (CCTA) to quantify coronary stenosis, myocardial blood flow (MBF), and extracellular volume (ECV). The proportion of patients with microvascular myocardial ischemia, defined as any myocardial segment with a mean MBF ≤ of 100 mL/min/100 mL, in patients without obstructive CAD (Coronary Artery Disease-Reporting and Data System [CAD-RADS] grade 0-2 on CCTA) was determined. Various quantitative parameters of the patients with and without diabetes without obstructive CAD were compared. Multivariable analysis was used to determine the association between microvascular myocardial ischemia and angina symptoms in diabetic patients without obstructive CAD. Results: One hundred and fifty-two diabetic patients (mean age: 59.7 ± 10.7; 77 males) and 266 non-diabetic patients (62.0 ± 12.3; 167 males) were enrolled; CCTA revealed 113 and 155 patients without obstructive CAD, respectively. For patients without obstructive CAD, the mean global MBF was significantly lower for those with diabetes than for those without (152.8 mL/min/100 mL vs. 170.4 mL/min/100 mL, P < 0.001). The mean ECV was significantly higher for diabetic patients (27.2% vs. 25.8%, P = 0.009). Among the patients without obstructive CAD, the incidence of microvascular myocardial ischemia (36.3% [41/113] vs. 10.3% [16/155], P < 0.001) and interstitial fibrosis (69.9% [79/113] vs. 33.3% [8/24], P = 0.001) were significantly higher in diabetic patients than in the controls. The presence of microvascular myocardial ischemia was independently associated with angina symptoms (adjusted odds ratio = 3.439, P = 0.037) in diabetic patients but without obstructive CAD. Conclusion: Dynamic CT-MPI + CCTA revealed a high incidence of microvascular myocardial ischemia in diabetic patients without obstructive CAD. Microvascular myocardial ischemia is strongly associated with angina.