1. Articles from takashi kubo

    1-24 of 107 1 2 3 4 5 »
    1. Radial wall strain: a novel angiographic measure of plaque composition and vulnerability

      Radial wall strain: a novel angiographic measure of plaque composition and vulnerability

      Background: The lipid-to-cap ratio (LCR) and thin-cap fibroatheroma (TCFA) derived from optical coherence tomography (OCT) are indicative of plaque vulnerability. Aims: We aimed to explore the association of a novel method to estimate radial wall strain (RWS) from angiography with plaque composition and features of vulnerability assessed by OCT. Methods: Anonymised data from patients with intermediate stenosis who underwent coronary angiography (CAG) and OCT were analysed in a core laboratory. Angiography-derived RWS max was computed as the maximum deformation of lumen diameter throughout the cardiac cycle, expressed as a percentage of the largest lumen diameter. The LCR and TCFA were ...

      Read Full Article
    2. Automated diagnosis of optical coherence tomography imaging on plaque vulnerability and its relation to clinical outcomes in coronary artery disease

      Automated diagnosis of optical coherence tomography imaging on plaque vulnerability and its relation to clinical outcomes in coronary artery disease

      This study sought to develop a deep learning-based diagnostic algorithm for plaque vulnerability by analyzing intravascular optical coherence tomography (OCT) images and to investigate the relation between AI-plaque vulnerability and clinical outcomes in patients with coronary artery disease (CAD). A total of 1791 study patients who underwent OCT examinations were recruited from a multicenter clinical database, and the OCT images were first labeled as either normal, a stable plaque, or a vulnerable plaque by expert cardiologists. A DenseNet-121-based deep learning algorithm for plaque characterization was developed by training with 44,947 prelabeled OCT images, and demonstrated excellent differentiation among normal ...

      Read Full Article
    3. Optical coherence tomography criteria for stent optimisation

      Optical coherence tomography criteria for stent optimisation

      Intravascular optical coherence tomography (OCT) is a valuable imaging tool for guiding percutaneous coronary intervention (PCI). Previous OCT studies have demonstrated that stent abnormalities such as underexpansion, dissection, malapposition, and tissue protrusions are associated with PCI outcomes1. However, the quantitative OCT criteria of those stent abnormalities for the requirement of additional procedures have not yet been clarified. Interventional cardiologists have determined PCI endpoints based on their own experience or local rules in OCT-guided PCI. To standardise OCT-guided PCI, it is necessary to develop quantitative OCT criteria for stent optimisation.

      Read Full Article
    4. Optical coherence tomography in coronary atherosclerosis assessment and intervention

      Optical coherence tomography in coronary atherosclerosis assessment and intervention

      Since optical coherence tomography (OCT) was first performed in humans two decades ago, this imaging modality has been widely adopted in research on coronary atherosclerosis and adopted clinically for the optimization of percutaneous coronary intervention. In the past 10 years, substantial advances have been made in the understanding of in vivo vascular biology using OCT. Identification by OCT of culprit plaque pathology could potentially lead to a major shift in the management of patients with acute coronary syndromes. Detection by OCT of healed coronary plaque has been important in our understanding of the mechanisms involved in plaque destabilization and healing ...

      Read Full Article
    5. Impact of coronary plaque morphology on the precision of computational fractional flow reserve derived from optical coherence tomography imaging

      Impact of coronary plaque morphology on the precision of computational fractional flow reserve derived from optical coherence tomography imaging

      Background: Computational fractional flow reserve (FFR) was recently developed to expand the use of physiology-guided percutaneous coronary intervention (PCI). Nevertheless, current methods do not account for plaque composition. It remains unknown whether the numerical precision of computational FFR is impacted by the plaque composition in the interrogated vessels. Methods: This study is an observational, retrospective, cross-sectional study. Patients who underwent both optical coherence tomography (OCT) and FFR prior to intervention between August 2011 and October 2018 at Wakayama Medical University Hospital were included. All frames from OCT pullbacks were analyzed using a deep learning algorithm to obtain coronary plaque morphology ...

      Read Full Article
    6. Combined Use of Multiple Intravascular Imaging Techniques in Acute Coronary Syndrome

      Combined Use of Multiple Intravascular Imaging Techniques in Acute Coronary Syndrome

      Recent advances in intravascular imaging techniques have made it possible to assess the culprit lesions of acute coronary syndrome (ACS) in the clinical setting. Intravascular ultrasound (IVUS) is the most commonly used intravascular imaging technique that provides cross-sectional images of coronary arteries. IVUS can assess plaque burden and vessel remodeling. Optical coherence tomography (OCT) is a high-resolution (10 μm) intravascular imaging technique that uses near-infrared light. OCT can identify key features of atheroma, such as lipid core and thin fibrous cap. Near-infrared spectroscopy (NIRS) can detect lipid composition by analyzing the near-infrared absorption properties of coronary plaques. NIRS provides a ...

      Read Full Article
    7. Artificial intelligence and optical coherence tomography for the automatic characterisation of human atherosclerotic plaques

      Artificial intelligence and optical coherence tomography for the automatic characterisation of human atherosclerotic plaques

      Background: Intravascular optical coherence tomography (IVOCT) enables detailed plaque characterisation in vivo , but visual assessment is time-consuming and subjective. Aims: This study aimed to develop and validate an automatic framework for IVOCT plaque characterisation using artificial intelligence (AI). Methods: IVOCT pullbacks from five international centres were analysed in a core lab, annotating basic plaque components, inflammatory markers and other structures. A deep convolutional network with encoding-decoding architecture and pseudo-3D input was developed and trained using hybrid loss. The proposed network was integrated into commercial software to be externally validated on additional IVOCT pullbacks from three international core labs, taking the ...

      Read Full Article
    8. Automatic Coregistration Between Coronary Angiography and Intravascular Optical Coherence Tomography

      Automatic Coregistration Between Coronary Angiography and Intravascular Optical Coherence Tomography

      This study sought to evaluate a novel approach for automatic coregistration of optical coherence tomography (OCT) and coronary angiography. Lumen diameters and side branches from both coronary angiography and OCT were used to create 2 feature sets. Subsequently, a 2-step coregistration approach was performed on the feature sets for matching of each OCT cross section on the angiographic centerline. For validation, all side branches with 1.0 mm diameter were identi fied and used as paired fiduciary landmarks. Geographical error was de fi ned as the distance between the automatically coregistered and the true-paired landmarks. Altogether 212 vessels from 181 ...

      Read Full Article
    9. Usefulness of optical coherence tomography with angiographic coregistration in the guidance of coronary stent implantation

      Usefulness of optical coherence tomography with angiographic coregistration in the guidance of coronary stent implantation

      Optical coherence tomography (OCT)-angiography coregistration during stent implantation may be useful to avoid geographical mismatch and incomplete lesion coverage. Untreated lipid-rich plaque at stent edge is associated with subsequent stent edge restenosis. The present study sought to compare the frequency of untreated lipid-rich plaque at the stent edge between OCT-guided percutaneous coronary intervention (PCI) with and without OCT-angiography coregistration. We investigated 398 patients who underwent OCT-guided stent implantation (n = 198 in the coregistration group, and n = 200 in the no coregistration group). In OCT after PCI, untreated lipid-lich plaque was identified by the maximum lipid arc > 180˚ in the ...

      Read Full Article
    10. Evaluation of coronary plaques and atherosclerosis using optical coherence tomography

      Evaluation of coronary plaques and atherosclerosis using optical coherence tomography

      Introduction: Coronary angiography (CAG) is the standard modality for assessing coronary stenosis; however, it has limitations in assessing coronary plaque morphology. Optical coherence tomography (OCT) is a high-resolution (10-20μm) light-based intravascular imaging technique that can identify more detailed coronary plaque morphology compared to other intravascular imaging modalities. OCT is remarkable for characterizing fibrous, fibrocalcific, and lipid-rich plaques. The capabilities of OCT are well suited for discriminating three types of unstable plaque morphologies underlying coronary thrombosis, such as plaque rupture, erosion, and calcified nodules. The high resolution of OCT makes it possible to identify important features of vulnerable plaques, such ...

      Read Full Article
    11. Optical coherence tomography detection of vulnerable plaques at high risk of developing acute coronary syndrome

      Optical coherence tomography detection of vulnerable plaques at high risk of developing acute coronary syndrome

      Aims: The ability of optical coherence tomography (OCT) to detect plaques at high risk of developing acute coronary syndrome (ACS) remains unclear. The aim of this study was to evaluate the association between non-culprit plaques characterized as both lipid-rich plaque (LRP) and thin-cap fibroatheroma (TCFA) by OCT and the risk of subsequent ACS events at the lesion level. Methods and results: In 1378 patients who underwent OCT, 3533 non-culprit plaques were analysed for the presence of LRP (maximum lipid arc > 180°) and TCFA (minimum fibrous cap thickness < 65 μm). The median follow-up period was 6 years [interquartile range (IQR): 5-9 ...

      Read Full Article
    12. Automatic Characterisation of Human Atherosclerotic Plaque Composition from Intravascular Optical Coherence Tomography Using Artificial Intelligence

      Automatic Characterisation of Human Atherosclerotic Plaque Composition from Intravascular Optical Coherence Tomography Using Artificial Intelligence

      Background Intravascular optical coherence tomography (IVOCT) enables detailed plaque characterisation in-vivo, but visual assessment is time-consuming and subjective. Aims This study aims to develop and validate an automatic framework for IVOCT plaque characterisation using artificial intelligence (AI). Methods IVOCT pullbacks from 5 international centres were analysed in a corelab, annotating basic plaque components, inflammatory markers and other structures. A deep convolutional network with encoding-decoding architecture and pseudo-3D input was developed and trained using hybrid loss. The proposed network was integrated into commercial software to be externally validated on additional IVOCT pullbacks from three international corelabs, taking the consensus among corelabs ...

      Read Full Article
    13. Impact of Optical Coherence Tomography Imaging on Decision-Making During Percutaneous Coronary Intervention in Patients Presented With Acute Coronary Syndromes

      Impact of Optical Coherence Tomography Imaging on Decision-Making During Percutaneous Coronary Intervention in Patients Presented With Acute Coronary Syndromes

      Background: Optical coherence tomography (OCT) provides valuable information to guide percutaneous coronary intervention (PCI) in acute coronary syndrome (ACS) regarding lesion preparation, stent sizing, and optimization. The aim of the present study was to compare lumen expansion of stent-treated lesions immediately after the procedure for ACS between OCT-guided PCI and angiography-guided PCI.Methods and Results:This study investigated stent-treated lesions immediately after PCI for ACS by using quantitative coronary angiography in 390 patients; 260 patients with OCT-guided PCI and 130 patients with angiography-guided PCI. Before stenting, the frequency of pre-dilatation and thrombus aspiration were not different between the OCT-guided and ...

      Read Full Article
    14. Prevalence, Features, and Prognosis of Artery-to-Artery Embolic ST-Segment-Elevation Myocardial Infarction: An Optical Coherence Tomography Study

      Prevalence, Features, and Prognosis of Artery-to-Artery Embolic ST-Segment-Elevation Myocardial Infarction: An Optical Coherence Tomography Study

      Background The major underlying mechanisms contributing to acute coronary syndrome are plaque rupture, plaque erosion, and calcified nodule. Artery-to-artery embolic myocardial infarction (AAEMI) was defined as ST-segment-elevation myocardial infarction caused by migrating thrombus formed at the proximal ruptured plaque. The aim of this study was to investigate the prevalence and clinical features of AAEMI by using optical coherence tomography. Methods and Results This study retrospectively enrolled 297 patients with ST-segment-elevation myocardial infarction who underwent optical coherence tomography before percutaneous coronary intervention. Patients were divided into 4 groups consisting of plaque rupture, plaque erosion, calcified nodule, and AAEMI according to optical ...

      Read Full Article
    15. NIRS-IVUS for Differentiating Coronary Plaque Rupture, Erosion and Calcified Nodule in Acute Myocardial Infarction

      NIRS-IVUS for Differentiating Coronary Plaque Rupture, Erosion and Calcified Nodule in Acute Myocardial Infarction

      Objectives This study sought to investigate the ability of combined near-infrared spectroscopy and intravascular ultrasound (NIRS-IVUS) to differentiate plaque rupture (PR), plaque erosion (PE), or calcified nodule (CN) in acute myocardial infarction (AMI). Background Most acute coronary syndromes occur from coronary thrombosis based on PR, PE, or CN. In vivo differentiation among PR, PE, and CN is a major challenge for intravascular imaging. Methods The study enrolled 244 patients with AMI who had a de novo culprit lesion in a native coronary artery. The culprit lesions were assessed by both NIRS-IVUS and optical coherence tomography (OCT). Maximum lipid core burden ...

      Read Full Article
    16. Comparison of Optical Flow Ratio and Fractional Flow Ratio in Stent-Treated Arteries Immediately After Percutaneous Coronary Intervention

      Comparison of Optical Flow Ratio and Fractional Flow Ratio in Stent-Treated Arteries Immediately After Percutaneous Coronary Intervention

      Background: Optical flow ratio (OFR) is a recently developed method for functional assessment of coronary artery disease based on computational fluid dynamics of vascular anatomical data from intravascular optical coherence tomography (OCT). The purpose of this study was to investigate the relationship between OFR and fractional flow reserve (FFR) in stent-treated arteries immediately after percutaneous coronary intervention (PCI). Methods and Results: The OFR and FFR were measured in 103 coronary arteries immediately after successful PCI with a stent. An increase in the OFR and FFR values within the stent was defined as in-stent ∆OFR and ∆FFR, respectively. The values of ...

      Read Full Article
    17. Optical Coherence Tomography Comparison of Percutaneous Coronary Intervention Among Plaque Rupture, Erosion, and Calcified Nodule in Acute Myocardial Infarction

      Optical Coherence Tomography Comparison of Percutaneous Coronary Intervention Among Plaque Rupture, Erosion, and Calcified Nodule in Acute Myocardial Infarction

      Background: Acute myocardial infarction (AMI) is caused by coronary plaque rupture (PR), plaque erosion (PE), or calcified nodule (CN). We used optical coherence tomography (OCT) to compare stent expansion immediately after primary percutaneous coronary intervention (PCI) in patients with AMI caused by PR, PE, or CN. Methods and Results: In all, 288 AMI patients were assessed by OCT before and immediately after PCI, performed with OCT guidance according to OPINION criteria for stent sizing and optimization. The frequency of OCT-identified PR (OCT-PR), OCT-PE, and OCT-CN was 172 (60%), 82 (28%), and 34 (12%), respectively. Minimum stent area was smallest in ...

      Read Full Article
    18. Extent of the difference between microcatheter and pressure wire-derived fractional flow reserve and its relation to optical coherence tomography-derived parameters

      Extent of the difference between microcatheter and pressure wire-derived fractional flow reserve and its relation to optical coherence tomography-derived parameters

      Background Although previous studies demonstrated that microcatheter-derived fractional flow reserve (mc-FFR) tends to overestimate lesion severity compared to pressure wire-derived FFR (pw-FFR), the clinical utility of mc-FFR remains obscure. The extent of differences between the two FFR systems and its relation to a lesion-specific parameter remain unknown. In this study, we sought to compare mc-FFR with pw-FFR and determine the lower and upper mc-FFR cut-offs predicting ischemic and non-ischemic stenosis, using an ischemic and a clinical FFR threshold of 0.75 and 0.80 as references, respectively. We further explored optical coherence tomography (OCT) parameters influencing the difference in FFR ...

      Read Full Article
    19. Comparison of Diagnostic Performance of Intracoronary Optical Coherence Tomography-based and Angiography-based Fractional Flow Reserve for Evaluation of Coronary Stenosis

      Comparison of Diagnostic Performance of Intracoronary Optical Coherence Tomography-based and Angiography-based Fractional Flow Reserve for Evaluation of Coronary Stenosis

      Aims: To evaluate the diagnostic performance of OCT-based optical flow ratio (OFR) in unselected patients and compare it with angiography-based quantitative flow ratio (QFR), using wire-based FFR as reference standard. Methods and results: All patients with OCT and FFR assessment prior to revascularization were analyzed. OFR and QFR were computed in blinded fashion and compared with FFR, all applying same cut-off value of ≤0.80 to define ischemia. Paired comparison between OFR and QFR was performed in 212 vessels from 181 patients. Average FFR was 0.82±0.10 and 40.1% vessels had FFR≤0.80. OFR showed significant ...

      Read Full Article
    20. A Local Multi-Layer Model for Tissue Classification of in-vivo Atherosclerotic Plaques in Intravascular Optical Coherence Tomography

      A Local Multi-Layer Model for Tissue Classification of in-vivo Atherosclerotic Plaques in Intravascular Optical Coherence Tomography

      Clinical researches show that the morbidity of coronary artery disease (CAD) is gradually increasing in many countries every year, and it causes hundreds of thousands of people all over the world dying for each year. As the optical coherence tomography with high resolution and better contrast applied to the lesion tissue investigation of human vessel, many more micro-structures of the vessel could be easily and clearly visible to doctors, which help to improve the CAD treatment effect. Manual qualitative analysis and classification of vessel lesion tissue are time-consuming to doctors because a single-time intravascular optical coherence (IVOCT) data set of ...

      Read Full Article
    21. Expert consensus statement for quantitative measurement and morphological assessment of optical coherence tomography

      Expert consensus statement for quantitative measurement and morphological assessment of optical coherence tomography

      In this document, the methods for the quantitative measurement and morphological assessment of optical coherence tomography (OCT)/optical frequency domain imaging images (OFDI) are briefly summarized. The focus is on the clinical application of OCT/OFDI to guide percutaneous coronary interventions.

      Read Full Article
    22. Intracoronary pressure increase due to contrast injection for optical coherence tomography imaging

      Intracoronary pressure increase due to contrast injection for optical coherence tomography imaging

      Background Optical coherence tomography (OCT) requires intracoronary injection of contrast media to remove blood from the field of view during image acquisition. Contrast injection may cause a temporal increase in intracoronary pressure. The aim of this study was to compare the intracoronary pressure during contrast injection between OCT and coronary angiography . Methods We measured intracoronary pressure by using a pressure guidewire during contrast injection for OCT and angiography in 30 coronary arteries (mean fractional flow reserve = 0.90 ± 0.03). Contrast media was injected into coronary artery through the guiding catheter by using a mechanical injector pump. Results Intracoronary pressure ...

      Read Full Article
    23. Early and mid-term vascular responses to optical coherence tomography guided everolimus-eluting stent implantation in stable coronary artery disease

      Early and mid-term vascular responses to optical coherence tomography guided everolimus-eluting stent implantation in stable coronary artery disease

      Background Analysis of pooled clinical data has shown the safety of 3 months of dual antiplatelet therapy (DAPT) with everolimus-eluting cobalt–chromium stents (Co-Cr EESs). This study evaluated early and mid-term vascular responses to Co-Cr EESs in patients with stable coronary artery disease (CAD). Methods The MECHANISM-Elective trial (NCT02014818) is a multicenter optical coherence tomography (OCT) registry. Enrolled patients were evaluated by OCT immediately after EES implantation (post), were prospectively allocated to either 1 month (n = 50) or 3 months (n = 50) OCT follow-up, and then received a 12 months OCT evaluation. The incidences of intrastent thrombus (IS-Th) and irregular ...

      Read Full Article
    24. Imaging assessment and accuracy in coronary artery autopsy: comparison of frequency-domain optical coherence tomography with intravascular ultrasound and histology

      Imaging assessment and accuracy in coronary artery autopsy: comparison of frequency-domain optical coherence tomography with intravascular ultrasound and histology

      ptical coherence tomography (OCT) is a coronary artery imaging technique with high resolution. Second-generation frequency-domain OCT (FD-OCT) technology allows safer and faster clinical application compared with first-generation time-domain OCT (TD-OCT). Only limited validation studies compare FD-OCT with other modes of analysis: histology, which is the current gold standard, and intravascular ultrasound (IVUS). This study therefore aims to demonstrate the accuracy of FD-OCT images compared with IVUS and histology. FD-OCT and IVUS images were acquired from 203 segments from 31 coronary arteries obtained at autopsy from 20 cadavers. Of these, 30 randomly-selected pairs were used to create three classifications of plaque ...

      Read Full Article
    1-24 of 107 1 2 3 4 5 »
  1. Categories

    1. Applications:

      Art, Cardiology, Dentistry, Dermatology, Developmental Biology, Gastroenterology, Gynecology, Microscopy, NDE/NDT, Neurology, Oncology, Ophthalmology, Other Non-Medical, Otolaryngology, Pulmonology, Urology
    2. Business News:

      Acquisition, Clinical Trials, Funding, Other Business News, Partnership, Patents
    3. Technology:

      Broadband Sources, Probes, Tunable Sources
    4. Miscellaneous:

      Jobs & Studentships, Student Theses, Textbooks
  2. Topics in the News

    1. (100 articles) Wakayama Medical University
    2. (23 articles) Abbott
    3. (8 articles) Kobe University Graduate School of Medicine
    4. (6 articles) Cardiovascular Research Foundation
    5. (5 articles) Shanghai Jiao Tong University
    6. (4 articles) National University of Ireland, Galway
    7. (4 articles) Kawasaki Medical School
    8. (3 articles) Nara Medical University
    9. (3 articles) Massachusetts General Hospital
    10. (3 articles) Aarhus University
    11. (1 articles) Academic Medical Center at the University of Amsterdam
    12. (1 articles) University College London
    13. (1 articles) University of Cologne
  3. Popular Articles

  4. Picture Gallery

    Optical coherence tomography in unprotected left main coronary artery stenting Relation of Microchannel Structure Identified by Optical Coherence Tomography to Plaque Vulnerability in Patients With Coronary Artery Disease Plaque and thrombus evaluation by optical coherence tomography Virtual Histology Intravascular Ultrasound Compared With Optical Coherence Tomography for Identification of Thin-Cap Fibroatheroma Consensus Standards for Acquisition, Measurement, and Reporting of Intravascular Optical Coherence Tomography Studies: A Report From the International Working Group for Intravascular Optical Coherence Tomography Standardization and Validation OCT Compared With IVUS in a Coronary Lesion Assessment The OPUS-CLASS Study A Deep Learning Framework for the Detection and Quantification of Reticular Pseudodrusen and Drusen on Optical Coherence Tomography Quantitative assessment of textural features in the early detection of diabetic retinopathy with optical coherence tomography angiography Line-field confocal optical coherence tomography of fibroepithelioma of Pinkus Assessment of demineralized tooth lesions using optical coherence tomography and other state-of-the-art technologies: a review Optic disc and retinal vessel densities assessment by optical coherence tomography angiography in patients with keratoconus Optical coherence tomography angiography in Bietti crystalline dystrophy