1.Coronary CT AngiographyBased Assessment of Coronary in-Stent Restenosis:A Journey through Past and Present Trends
Yoon Seong LEE ; Eun-Ah PARK ; Whal LEE
Journal of the Korean Society of Radiology 2024;85(2):258-269
Treatment of patients with coronary artery disease commonly involves the use of balloon-expandable stent placements, currently recognized as the most prevalent approach for coronary artery revascularization. Nevertheless, the occurrence of restenosis remains a significant complication following percutaneous coronary interventions. The diagnostic role of coronary CT angiography (CCTA) in detecting stent restenosis has limitations primarily attributable to challenges in accurately discerning the lumen, due to issues such as blooming and motion artifacts. As a result, many cases often necessitate a transition to conventional coronary angiography. However, recent advancements in CT technology have led to notable improvements in both sensitivity and specificity, underscoring the growing significance of CCTA as a diagnostic tool. The consistent reporting of high negative predictive value is particularly noteworthy. This review aims to explore the historical context, current status, and recent trends in diagnosing coronary artery stent restenosis using CCTA.
2.2024 Consensus Statement on Coronary Stenosis and Plaque Evaluation in CT Angiography From the Asian Society of Cardiovascular Imaging-Practical Tutorial (ASCI-PT)
Cherry KIM ; Chul Hwan PARK ; Bae Young LEE ; Chan Ho PARK ; Eun-Ju KANG ; Hyun Jung KOO ; Kakuya KITAGAWA ; Min Jae CHA ; Rungroj KRITTAYAPHONG ; Sang Il CHOI ; Hwan Seok YONG ; Sung Min KO ; Sung Mok KIM ; Sung Ho HWANG ; Nguyen Ngoc TRANG ; Whal LEE ; Young Jin KIM ; Jongmin LEE ; Dong Hyun YANG
Cardiovascular Imaging Asia 2024;8(2):21-31
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.
3.Coronary CT AngiographyBased Assessment of Coronary in-Stent Restenosis:A Journey through Past and Present Trends
Yoon Seong LEE ; Eun-Ah PARK ; Whal LEE
Journal of the Korean Society of Radiology 2024;85(2):258-269
Treatment of patients with coronary artery disease commonly involves the use of balloon-expandable stent placements, currently recognized as the most prevalent approach for coronary artery revascularization. Nevertheless, the occurrence of restenosis remains a significant complication following percutaneous coronary interventions. The diagnostic role of coronary CT angiography (CCTA) in detecting stent restenosis has limitations primarily attributable to challenges in accurately discerning the lumen, due to issues such as blooming and motion artifacts. As a result, many cases often necessitate a transition to conventional coronary angiography. However, recent advancements in CT technology have led to notable improvements in both sensitivity and specificity, underscoring the growing significance of CCTA as a diagnostic tool. The consistent reporting of high negative predictive value is particularly noteworthy. This review aims to explore the historical context, current status, and recent trends in diagnosing coronary artery stent restenosis using CCTA.
4.Coronary CT AngiographyBased Assessment of Coronary in-Stent Restenosis:A Journey through Past and Present Trends
Yoon Seong LEE ; Eun-Ah PARK ; Whal LEE
Journal of the Korean Society of Radiology 2024;85(2):258-269
Treatment of patients with coronary artery disease commonly involves the use of balloon-expandable stent placements, currently recognized as the most prevalent approach for coronary artery revascularization. Nevertheless, the occurrence of restenosis remains a significant complication following percutaneous coronary interventions. The diagnostic role of coronary CT angiography (CCTA) in detecting stent restenosis has limitations primarily attributable to challenges in accurately discerning the lumen, due to issues such as blooming and motion artifacts. As a result, many cases often necessitate a transition to conventional coronary angiography. However, recent advancements in CT technology have led to notable improvements in both sensitivity and specificity, underscoring the growing significance of CCTA as a diagnostic tool. The consistent reporting of high negative predictive value is particularly noteworthy. This review aims to explore the historical context, current status, and recent trends in diagnosing coronary artery stent restenosis using CCTA.
5.2024 Consensus Statement on Coronary Stenosis and Plaque Evaluation in CT Angiography From the Asian Society of Cardiovascular Imaging-Practical Tutorial (ASCI-PT)
Cherry KIM ; Chul Hwan PARK ; Bae Young LEE ; Chan Ho PARK ; Eun-Ju KANG ; Hyun Jung KOO ; Kakuya KITAGAWA ; Min Jae CHA ; Rungroj KRITTAYAPHONG ; Sang Il CHOI ; Hwan Seok YONG ; Sung Min KO ; Sung Mok KIM ; Sung Ho HWANG ; Nguyen Ngoc TRANG ; Whal LEE ; Young Jin KIM ; Jongmin LEE ; Dong Hyun YANG
Korean Journal of Radiology 2024;25(4):331-342
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.
6.Semi-Quantitative Scoring of Late Gadolinium Enhancement of the Left Ventricle in Patients with Ischemic Cardiomyopathy: Improving Interobserver Reliability and Agreement Using Consensus Guidance from the Asian Society of Cardiovascular Imaging-Practical Tutorial (ASCI-PT) 2020
Cherry KIM ; Chul Hwan PARK ; Do Yeon KIM ; Jaehyung CHA ; Bae Young LEE ; Chan Ho PARK ; Eun-Ju KANG ; Hyun Jung KOO ; Kakuya KITAGAWA ; Min Jae CHA ; Rungroj KRITTAYAPHONG ; Sang Il CHOI ; Sanjaya VISWAMITRA ; Sung Min KO ; Sung Mok KIM ; Sung Ho HWANG ; Nguyen Ngoc TRANG ; Whal LEE ; Young Jin KIM ; Jongmin LEE ; Dong Hyun YANG
Korean Journal of Radiology 2022;23(3):298-307
Objective:
This study aimed to evaluate the effect of implementing the consensus statement from the Asian Society of Cardiovascular Imaging-Practical Tutorial 2020 (ASCI-PT 2020) on the reliability of cardiac MR with late gadolinium enhancement (CMR-LGE) myocardial viability scoring between observers in the context of ischemic cardiomyopathy.
Materials and Methods:
A total of 17 cardiovascular imaging experts from five different countries evaluated CMR obtained in 26 patients (male:female, 23:3; median age [interquartile range], 55.5 years [50–61.8]) with ischemic cardiomyopathy. For LGE scoring, based on the 17 segments, the extent of LGE in each segment was graded using a five-point scoring system ranging from 0 to 4 before and after exposure according to the consensus statement. All scoring was performed via webbased review. Scores for slices, vascular territories, and total scores were obtained as the sum of the relevant segmental scores. Interobserver reliability for segment scores was assessed using Fleiss’ kappa, while the intraclass correlation coefficient (ICC) was used for slice score, vascular territory score, and total score. Inter-observer agreement was assessed using the limits of agreement from the mean (LoA).
Results:
Interobserver reliability (Fleiss’ kappa) in each segment ranged 0.242–0.662 before the consensus and increased to 0.301–0.774 after the consensus. The interobserver reliability (ICC) for each slice, each vascular territory, and total score increased after the consensus (slice, 0.728–0.805 and 0.849–0.884; vascular territory, 0.756–0.902 and 0.852–0.941; total score, 0.847 and 0.913, before and after implementing the consensus statement, respectively. Interobserver agreement in scoring also improved with the implementation of the consensus for all slices, vascular territories, and total score. The LoA for the total score narrowed from ± 10.36 points to ± 7.12 points.
Conclusion
The interobserver reliability and agreement for CMR-LGE scoring for ischemic cardiomyopathy improved when following guidance from the ASCI-PT 2020 consensus statement.
7.Beyond Coronary CT Angiography: CT Fractional Flow Reserve and Perfusion
Moon Young KIM ; Dong Hyun YANG ; Ki Seok CHOO ; Whal LEE
Journal of the Korean Radiological Society 2022;83(1):3-27
Cardiac CT has been proven to provide diagnostic and prognostic evaluation of coronary artery disease for cardiovascular risk stratification and treatment decision-making based on rapid technological development and various research evidence. Coronary CT angiography has emerged as a gateway test for coronary artery disease that can reduce invasive angiography due to its high negative predictive value, but the diagnostic specificity is relatively low. However, coronary CT angiography is likely to overcome its limitations through functional evaluation to identify the hemodynamic significance of coronary artery disease by analyzing myocardial perfusion and fractional flow reserve through cardiac CT. Recently, studies have been actively conducted to incorporate artificial intelligence to make this more objective and reproducible. In this review, functional imaging techniques of cardiac computerized tomography are explored.
8.Left atrial wall thickness and its relationship with reconnection after pulmonary vein isolation in patients with atrial fibrillation evaluated using a three‑dimensional wall thickness map
Seil OH ; Yoon Ha JOO ; Euijae LEE ; So‑Ryoung LEE ; Myung‑Jin CHA ; Eue‑Keun CHOI ; Jung Chan LEE ; Whal LEE
International Journal of Arrhythmia 2021;22(4):16-
Background:
The major cause of recurrence after pulmonary vein (PV) isolation for atrial fibrillation (AF) is PV recon‑ nection, and thicker wall could be associated with reconnection.
Objectives:
This study aimed to evaluate the wall thickness of the PV antrum in reconnection sites using a threedimensional (3D) wall thickness map.
Methods:
A total of 91 patients who underwent a second ablation procedure due to AF recurrence were evalu‑ ated. The locations of the PV reconnection sites were confirmed in electroanatomical maps. A 3D atrial wall thickness (AWT) map was created using computed tomography scan data. The AWT values of the ablation lines of the index procedure were graded in each segment of the PV antrum: grade 1, 0.5 < AWT ≤ 1.0 mm; grade 2, 1.0 < AWT ≤ 1.5 mm; grade 3, 1.5 < AWT ≤ 2.0 mm; grade 4, 2.0 < AWT ≤ 2.5 mm; grade 5, AWT > 2.5 mm.
Results:
A total of 281 PV reconnection sites among 1256 segments of the PV antrum in 79 patients were detected. The average AWT grades were 2.7 ± 1.0 and 2.2 ± 1.0 in the reconnected and non-reconnected segments, respectively (P < 0.01). Higher AWT grades were observed in the reconnected superior segments of the left superior PV, carina and inferior segments of the left inferior PV, superior and posterior segments of the right superior PV, and posterior and inferior segments of the right inferior PV.
Conclusion
The reconnected segments of the PV antrum showed thicker myocardium than the non-reconnected ones in patients with recurrent AF after catheter ablation. A wall thickness map for PV isolation could be considered for customized ablation in order to reduce PV reconnection.
9.Coronary Artery Lumen Segmentation Using Location– Adaptive Threshold in Coronary Computed Tomographic Angiography: A Proof-of-Concept
Cheong-Il SHIN ; Sang Joon PARK ; Ji-Hyun KIM ; Yeonyee Elizabeth YOON ; Eun-Ah PARK ; Bon-Kwon KOO ; Whal LEE
Korean Journal of Radiology 2021;22(5):688-696
Objective:
To compare the lumen parameters measured by the location-adaptive threshold method (LATM), in which the inter- and intra-scan attenuation variabilities of coronary computed tomographic angiography (CCTA) were corrected, and the scan-adaptive threshold method (SATM), in which only the inter-scan variability was corrected, with the reference standard measurement by intravascular ultrasonography (IVUS).
Materials and Methods:
The Hounsfield unit (HU) values of whole voxels and the centerline in each of the cross-sections of the 22 target coronary artery segments were obtained from 15 patients between March 2009 and June 2010, in addition to the corresponding voxel size. Lumen volume was calculated mathematically as the voxel volume multiplied by the number of voxels with HU within a given range, defined as the lumen for each method, and compared with the IVUS-derived reference standard. Subgroup analysis of the lumen area was performed to investigate the effect of lumen size on the studied methods.Bland-Altman plots were used to evaluate the agreement between the measurements.
Results:
Lumen volumes measured by SATM was significantly smaller than that measured by IVUS (mean difference, 14.6 ㎣ ; 95% confidence interval [CI], 4.9–24.3 ㎣ ); the lumen volumes measured by LATM and IVUS were not significantly different (mean difference, -0.7 ㎣ ; 95% CI, -9.1–7.7 ㎣ ). The lumen area measured by SATM was significantly smaller than that measured by LATM in the smaller lumen area group (mean of difference, 1.07 ㎟ ; 95% CI, 0.89–1.25 ㎟ ) but not in the larger lumen area group (mean of difference, -0.07 ㎟ ; 95% CI, -0.22–0.08 ㎟ ). In the smaller lumen group, the mean difference was lower in the Bland-Altman plot of IVUS and LATM (0.46 ㎟ ; 95% CI, 0.27–0.65 ㎟ ) than in that of IVUS and SATM (1.53 ㎟ ; 95% CI, 1.27–1.79㎟ ).
Conclusion
SATM underestimated the lumen parameters for computed lumen segmentation in CCTA, and this may be overcome by using LATM.
10.Three-Dimensional Printing of Congenital Heart Disease Models for Cardiac Surgery Simulation: Evaluation of Surgical Skill Improvement among Inexperienced Cardiothoracic Surgeons
Ju Gang NAM ; Whal LEE ; Baren JEONG ; Eun-Ah PARK ; Ji Yeon LIM ; Yujin KWAK ; Hong-Gook LIM
Korean Journal of Radiology 2021;22(5):706-713
Objective:
To evaluate the impact of surgical simulation training using a three-dimensional (3D)-printed model of tetralogy of Fallot (TOF) on surgical skill development.
Materials and Methods:
A life-size congenital heart disease model was printed using a Stratasys Object500 Connex2 printer from preoperative electrocardiography-gated CT scans of a 6-month-old patient with TOF with complex pulmonary stenosis.Eleven cardiothoracic surgeons independently evaluated the suitability of four 3D-printed models using composite Tango 27, 40, 50, and 60 in terms of palpation, resistance, extensibility, gap, cut-through ability, and reusability of. Among these, Tango 27 was selected as the final model. Six attendees (two junior cardiothoracic surgery residents, two senior residents, and two clinical fellows) independently performed simulation surgeries three times each. Surgical proficiency was evaluated by an experienced cardiothoracic surgeon on a 1–10 scale for each of the 10 surgical procedures. The times required for each surgical procedure were also measured.
Results:
In the simulation surgeries, six surgeons required a median of 34.4 (range 32.5–43.5) and 21.4 (17.9–192.7) minutes to apply the ventricular septal defect (VSD) and right ventricular outflow tract (RVOT) patches, respectively, on their first simulation surgery. These times had significantly reduced to 17.3 (16.2–29.5) and 13.6 (10.3–30.0) minutes, respectively, in the third simulation surgery (p = 0.03 and p = 0.01, respectively). The decreases in the median patch appliance time among the six surgeons were 16.2 (range 13.6–17.7) and 8.0 (1.8–170.3) minutes for the VSD and RVOT patches, respectively. Summing the scores for the 10 procedures showed that the attendees scored an average of 28.58 ± 7.89 points on the first simulation surgery and improved their average score to 67.33 ± 15.10 on the third simulation surgery (p = 0.008).
Conclusion
Inexperienced cardiothoracic surgeons improved their performance in terms of surgical proficiency and operation time during the experience of three simulation surgeries using a 3D-printed TOF model using Tango 27 composite.

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