• Korean Circulation Journal
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• v.53 no.9
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• pp.581-593
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• 2023

In the catheterization laboratory, the measurement of physiological indexes can help identify functionally significant lesions and has become one of the standard methods to guide treatment decision-making. Plaque vulnerability refers to a coronary plaque susceptible to rupture, enabling risk prediction before coronary events, and it can be detected by defining a certain type of plaque morphology on coronary imaging modalities. Although coronary physiology and plaque vulnerability have been considered different attributes of coronary artery disease, the underlying pathophysiological basis and clinical data indicate a strong correlation between coronary hemodynamic properties and vulnerable plaque. In prediction of coronary events, emerging data have suggested independent and additional implications of a physiology-based approach to a plaque-based approach. This review covers the fundamental interplay between coronary physiology and plaque morphology during disease progression with clinical data supporting this relationship and examines the clinical relevance of physiological indexes in prediction of clinical outcomes and therapeutic decision-making along with plaque vulnerability.

• The Journal of the Korea Contents Association
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• v.12 no.10
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• pp.349-356
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• 2012

In the diagnosis of coronary artery atheromatous plaque, Cardiac computed tomography (Cardiac Computed Tomographic Angiography: CCTA) compared with IVUS(Intravascular Ultrasound: IVUS) investigate the diagnostic accuracy, Interested in CCTA atheromatous plaque in computed tomography values (Hounsfield Unit: HU) try to find out. From April 2006 to August 2008 among coronary artery disease(Coronary Artery Disease: CAD) patients with confirmed or suspicious of CAD by CCTA performed atherosclerotic plaques and found 200 patients who underwent IVUS were enrolled. 200 patients who underwent CCTA and IVUS results from the 476 plaque was found, IVUS results of the soft plaque(n; 84), fibrous plaque(n; 63), mixed plaque (n; 97), calcific plaque(n; 232). The results are classified according to the IVUS plaque in HU in the soft plaque : $53.8{\pm}10.5$, fibrous plaque : $108.1{\pm}20.0$, mixed plaque : $371.2{\pm}113.1$, and calcific plaque : $731.0{\pm}160.4$. CCTA had sensitivity of 97% and confidence interval of 95.0-98.3. This study that is the diagnosis of coronary atheromatous plaque for using CCTA, we confirm the high sensitivity and the confidence interval Based on IVUS results CCTA atheromatous plaque with HU in the analysis could be classified to characterize in the treatment of patients with CAD is expected to help.

• Korean Journal of Radiology
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• v.25 no.6
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• pp.518-539
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• 2024

Coronary computed tomography angiography (CCTA) has emerged as a pivotal tool for diagnosing and risk-stratifying patients with suspected coronary artery disease (CAD). Recent advancements in image analysis and artificial intelligence (AI) techniques have enabled the comprehensive quantitative analysis of coronary atherosclerosis. Fully quantitative assessments of coronary stenosis and lumen attenuation have improved the accuracy of assessing stenosis severity and predicting hemodynamically significant lesions. In addition to stenosis evaluation, quantitative plaque analysis plays a crucial role in predicting and monitoring CAD progression. Studies have demonstrated that the quantitative assessment of plaque subtypes based on CT attenuation provides a nuanced understanding of plaque characteristics and their association with cardiovascular events. Quantitative analysis of serial CCTA scans offers a unique perspective on the impact of medical therapies on plaque modification. However, challenges such as time-intensive analyses and variability in software platforms still need to be addressed for broader clinical implementation. The paradigm of CCTA has shifted towards comprehensive quantitative plaque analysis facilitated by technological advancements. As these methods continue to evolve, their integration into routine clinical practice has the potential to enhance risk assessment and guide individualized patient management. This article reviews the evolving landscape of quantitative plaque analysis in CCTA and explores its applications and limitations.

• Journal of the Korean Society of Radiology
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• v.83 no.1
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• pp.28-41
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• 2022

Acute coronary syndrome involves three types of coronary artery disease associated with sudden rupture of coronary artery plaque, and has a clinical presentation ranging from ST-segment elevation myocardial infarction (STEMI) to non-ST-segment elevation myocardial infarction (NSTEMI) or unstable angina. Cardiac CT can help quantify and characterize atherosclerotic plaques. According to a previous study, low-attenuation plaque, napkin ring sign, positive remodeling, spotty calcification, and increased perivascular fat attenuation are associated with plaque ruptures on cardiac CT. Therefore, coronary artery stenosis, as well as acute coronary artery syndrome, can be diagnosed using cardiac CT.

• 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 the Korean Society of Radiology
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• v.85 no.2
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• pp.270-296
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• 2024

Coronary CT angiography (CCTA) is recognized for its role as a gatekeeper for invasive coronary angiography in patients suspected of coronary artery disease because it can detect significant coronary stenosis with high accuracy. However, heavy plaque in the coronary artery makes it difficult to visualize the lumen, which can lead to errors in the interpretation of the CCTA results. This is primarily due to the limited spatial resolution of CT scanners, resulting in blooming artifacts caused by calcium. However, coronary stenosis with high calcium scores often requires evaluation using CCTA. Technological methods to overcome these limitations include the introduction of high-resolution CT scanners, the development of reconstruction techniques, and the subtraction technique. Methods to improve reading ability, such as the setting of appropriate window width and height, and evaluation of the position of calcified plaque and residual visibility of the lumen in cross-sectional images, are also recommended.

• Korean Journal of Radiology
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• v.25 no.4
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• pp.331-342
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• 2024

The Asian Society of Cardiovascular Imaging-Practical Tutorial (ASCI-PT) is an instructional initiative of the ASCI School designed to enhance educational standards. In 2021, the ASCI-PT was convened with the goal of formulating a consensus statement on the assessment of coronary stenosis and coronary plaque using coronary CT angiography (CCTA). Nineteen experts from four countries conducted thorough reviews of current guidelines and deliberated on eight key issues to refine the process and improve the clarity of reporting CCTA findings. The experts engaged in both online and on-site sessions to establish a unified agreement. This document presents a summary of the ASCI-PT 2021 deliberations and offers a comprehensive consensus statement on the evaluation of coronary stenosis and coronary plaque in CCTA.

• Korean Journal of Radiology
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• v.20 no.5
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• pp.729-738
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• 2019

Objective: To assess the effects of iterative model reconstruction (IMR) on image quality for demonstrating non-calcific high-risk plaque characteristics of coronary arteries. Materials and Methods: This study included 66 patients (53 men and 13 women; aged 39-76 years; mean age, 55 ± 13 years) having single-vessel disease with predominantly non-calcified plaques evaluated using prospective electrocardiogram-gated 256-slice CT angiography. Paired image sets were created using two types of reconstruction: hybrid iterative reconstruction (HIR) and IMR. Plaque characteristics were compared using the two algorithms. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the images and the CNR between the plaque and adjacent adipose tissue were also compared between the two reformatted methods. Results: Seventy-seven predominantly non-calcified plaques were detected. Forty plaques showed napkin-ring sign with the IMR reformatted method, while nineteen plaques demonstrated napkin-ring sign with HIR. There was no statistically significant difference in the presentation of positive remodeling, low attenuation plaque, and spotty calcification between the HIR and IMR reconstructed methods (all p > 0.5); however, there was a statistically significant difference in the ability to discern the napkin-ring sign between the two algorithms (χ² = 12.12, p < 0.001). The image noise of IMR was lower than that of HIR (10 ± 2 HU versus 12 ± 2 HU; p < 0.01), and the SNR and CNR of the images and the CNR between plaques and surrounding adipose tissues on IMR were better than those on HIR (p < 0.01). Conclusion: IMR can significantly improve image quality compared with HIR for the demonstration of coronary artery and atherosclerotic plaques using a 256-slice CT.

• Biomedical Science Letters
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• v.21 no.4
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• pp.198-207
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• 2015

ST-segment elevation myocardial infarction (STEMI) and chronic total occlusion (CTO) of coronary artery are well-known atherosclerotic vascular diseases. However, the difference of intima-media thickness and plaque characteristics of carotid arteries between STEMI and CTO patients were not directly compared in previous studies. Medical records of a total of 158 (101 STEMI, 57 CTO) patients, who underwent carotid artery ultrasonography, were selected for the analysis. The baseline characteristics, ultrasonography findings, and clinical outcomes of the two groups were compared. The prevalence of hypertension, diabetes mellitus, and dyslipidemia was significantly higher in CTO patients. Carotid intima-media thickness ($0.97{\pm}0.13$ vs. $0.78{\pm}0.17cm$, P < 0.0001) and number of plaques ($2.2{\pm}1.0$ vs. $1.7{\pm}1.2$, P < 0.0001) were greater in CTO than STEMI patients. Multiple (${\geq}3$) or echogenic plaques were more frequently observed in CTO patients. During the median follow-up duration of 27 months, major adverse cardiovascular events occurred in 31% of CTO and 14% of STEMI patients (P = 0.008). We found that, compared with STEMI, CTO patients have higher burden of carotid artery atherosclerosis associated with more comorbid diseases and poor clinical outcomes.

• 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.