• Journal of the Korean Society of Radiology
• /
• v.83 no.1
• /
• pp.54-69
• /
• 2022

Early detection of potential asymptomatic coronary artery disease is very important, as patients with sudden cardiac death often do not show symptoms such as chest pain or motor dyspnea. Coronary CT angiography (CCTA) has long been unjustified as a screening tool for asymptomatic patients because of the risks posed by radiation exposure. However, there are still various opinions regarding the usefulness of CCTA for screening for coronary artery disease (CAD) in asymptomatic healthy individuals or patients. This review investigated the usefulness of coronary artery calcium score and CCTA as screening tests for CAD in asymptomatic healthy individuals or patients through various literature reviews. With the development of CT technology, recent studies have been conducted in asymptomatic CAD patients with a reduced radiation dose of less than 1 mSv. A total of 2.6% of asymptomatic subjects on CCTA found significant CAD over 70%, and it was concluded that screening CCTA for CAD showed prognostic power in predicting the future occurrence of CAD in asymptomatic people. However, after the completion of the current NIH SCOT-HEART 2 study, it may be possible to determine whether CCTA is appropriate as a screening tool for CAD in asymptomatic healthy individuals.

• Journal of the Korean Society of Radiology
• /
• v.15 no.3
• /
• pp.337-344
• /
• 2021

Coronary artery calcification is associated with cardiovascular risk factors and metabolic syndrome, and several studies have already reported that coronary artery calcification score are closely related to the amount of atherosclerotic plaques. This study was conducted on 109 patients who underwent coronary calcium CT who visited the comprehensive health examination center in Daegu city during the period from December 2020 to February 2021. we would like to investigate the relationship between coronary artery calcification score and blood factors. As a result of the study, the abnormal group increased the risk of calcification by 1.113 times compared to the normal group in the waist circumference factor. In the fasting glucose factor, the abnormal group increased the risk of calcification by 1.036 times compared to the normal group, and in the triglyceride factor, the abnormal group was normal. As the risk of calcification increased 1.008 times compared to the group, the waist circumference factor, fasting glucose factor, and triglyceride factor were found to be factors affecting coronary artery calcification score. The risk of developing calcification is primarily associated with waist circumference, anemia and triglycerides, and health care and health checks are expected to help reduce the incidence of cardiovascular disease and reduce medical costs.

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

• Korean Journal of Radiology
• /
• v.20 no.1
• /
• pp.94-101
• /
• 2019

Objective: To investigate the efficacy of motion-correction algorithm (MCA) in improving coronary artery image quality and measurement accuracy using an anthropomorphic dynamic heart phantom and 256-detector row computed tomography (CT) scanner. Materials and Methods: An anthropomorphic dynamic heart phantom was scanned under a static condition and under heart rate (HR) simulation of 50-120 beats per minute (bpm), and the obtained images were reconstructed using conventional algorithm (CA) and MCA. We compared the subjective image quality of coronary arteries using a four-point scale (1, excellent; 2, good; 3, fair; 4, poor) and measurement accuracy using measurement errors of the minimal luminal diameter (MLD) and minimal luminal area (MLA). Results: Compared with CA, MCA significantly improved the subjective image quality at HRs of 110 bpm (1.3 ± 0.3 vs. 1.9 ± 0.8, p = 0.003) and 120 bpm (1.7 ± 0.7 vs. 2.3 ± 0.6, p = 0.006). The measurement error of MLD significantly decreased on using MCA at 110 bpm (11.7 ± 5.9% vs. 18.4 ± 9.4%, p = 0.013) and 120 bpm (10.0 ± 7.3% vs. 25.0 ± 16.5%, p = 0.013). The measurement error of the MLA was also reduced using MCA at 110 bpm (19.2 ± 28.1% vs. 26.4 ± 21.6%, p = 0.028) and 120 bpm (17.9 ± 17.7% vs. 34.8 ± 19.6%, p = 0.018). Conclusion: Motion-correction algorithm can improve the coronary artery image quality and measurement accuracy at a high HR using an anthropomorphic dynamic heart phantom and 256-detector row CT scanner.

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

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

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

• Korean Journal of Radiology
• /
• v.22 no.11
• /
• pp.1764-1776
• /
• 2021

Objective: This study aimed to validate a deep learning-based fully automatic calcium scoring (coronary artery calcium [CAC]_auto) system using previously published cardiac computed tomography (CT) cohort data with the manually segmented coronary calcium scoring (CAC_hand) system as the reference standard. Materials and Methods: We developed the CAC_auto system using 100 co-registered, non-enhanced and contrast-enhanced CT scans. For the validation of the CAC_auto system, three previously published CT cohorts (n = 2985) were chosen to represent different clinical scenarios (i.e., 2647 asymptomatic, 220 symptomatic, 118 valve disease) and four CT models. The performance of the CAC_auto system in detecting coronary calcium was determined. The reliability of the system in measuring the Agatston score as compared with CAC_hand was also evaluated per vessel and per patient using intraclass correlation coefficients (ICCs) and Bland-Altman analysis. The agreement between CAC_auto and CAC_hand based on the cardiovascular risk stratification categories (Agatston score: 0, 1-10, 11-100, 101-400, > 400) was evaluated. Results: In 2985 patients, 6218 coronary calcium lesions were identified using CAC_hand. The per-lesion sensitivity and false-positive rate of the CAC_auto system in detecting coronary calcium were 93.3% (5800 of 6218) and 0.11 false-positive lesions per patient, respectively. The CAC_auto system, in measuring the Agatston score, yielded ICCs of 0.99 for all the vessels (left main 0.91, left anterior descending 0.99, left circumflex 0.96, right coronary 0.99). The limits of agreement between CAC_auto and CAC_hand were 1.6 ± 52.2. The linearly weighted kappa value for the Agatston score categorization was 0.94. The main causes of false-positive results were image noise (29.1%, 97/333 lesions), aortic wall calcification (25.5%, 85/333 lesions), and pericardial calcification (24.3%, 81/333 lesions). Conclusion: The atlas-based CAC_auto empowered by deep learning provided accurate calcium score measurement as compared with manual method and risk category classification, which could potentially streamline CAC imaging workflows.

• Journal of radiological science and technology
• /
• v.34 no.4
• /
• pp.315-321
• /
• 2011

The goal of this study is to reduce patient exposure dose by providing image quality and radiation dose according to inspection methods. Volume Computed Tomography Dose Index(CTDIvol) and Dose Length Product(DLP) of prospective and retrospective ECG gating snapshot segment of Coronary CT angiography(CTA) were measured each snapshot segment methods. CT number, noise, uniformity, and resolution were also measured using phantom under the same condition of coronary CTA. The results showed that CT number, noise, uniformity and resolution are similar to each other. In terms of CTDIvol and DLP, however, measurement dose of prospective ECG gating snapshot segment was lower than the retrospective case by 37.5% and 40.3%. Therefore, it is highly recommended that in the coronary CTA, prospective ECG gating scan mode should be chosen to reduce patient dose.

• Journal of Cardiovascular Imaging
• /
• v.26 no.4
• /
• pp.238-246
• /
• 2018

BACKGROUND: Kawasaki disease (KD) sometimes presents with only fever and cervical lymphadenopathy before other clinical signs materialize. This lymphadenopathy-first-presenting Kawasaki disease (LKD) may be misdiagnosed as bacterial cervical lymphadenitis (BCL). We investigated characteristic imaging and clinical data for factors differentiating LKD from BCL. METHODS: We compared imaging, clinical, and laboratory data of patients with KD and BCL. We included patients admitted to a single tertiary center between January 2015 and July 2018. RESULTS: We evaluated data from 51 patients with LKD, 63 with BCL, and 218 with typical KD. Ultrasound imaging revealed multiple enlarged lymph nodes in both LKD and BCL patients. On the other hand, computed tomography (CT) showed more abscesses in patients with BCL. Patients with LKD were younger and showed higher systemic and hepatobiliary inflammatory markers and pyuria than BCL patients. In multivariable logistic regression, younger age and higher C-reactive protein (CRP) retained independent associations with LKD. A comparison of the echocardiographic findings in LKD and typical KD showed that patients with LKD did not have a higher incidence of coronary artery abnormalities (CAA). CONCLUSIONS: LKD patients tend to have no abscesses on CT and more elevated systemic hepatobiliary inflammatory markers and pyuria compared to BCL patients. The absence of abscess on CT, younger age, and elevated CRP were the most significant variables differentiating LKD from BCL. There was no difference in CAA between LKD and typical KD.