Purpose: In coronary computed tomographic angiography (CTA), low attenuation of coronary atherosclerotic plaque is associated with lipid-rich plaques. However, an overlap in Hounsfield units (HU) between fibrous and lipid-rich plaque as well as an influence of luminal enhancement on plaque attenuation was observed and may limit accurate detection of lipid-rich plaques by CTA. We sought to determine whether the quantitative histogram analysis improves accuracy of the detection of lipid-core plaque (LCP) in ex vivo hearts by validation against histological analysis. Materials and Methods: Human donor hearts were imaged with a 64-slice computed tomographic scanner using a standard coronary CTA protocol ...

The role of microcalcifications (μCalcs) in the biomechanics of vulnerable plaque rupture is examined. Our laboratory previously proposed (Ref. 44), using a very limited tissue sample, that μCalcs embedded in the fibrous cap proper could significantly increase cap instability. This study has been greatly expanded. Ninety-two human coronary arteries containing 62 fibroatheroma were examined using high-resolution microcomputed tomography at 6.7-μm resolution and undecalcified histology with special emphasis on calcified particles <50 μm in diameter. Our results reveal the presence of thousands of μCalcs, the vast majority in lipid pools where they are not dangerous. However, 81 μCalcs were ...

Objectives The purpose of this study was to determine the angiographic and optical coherence tomographic (OCT) characteristics of coronary lesions with recanalized thrombi. Background Although spontaneous recanalization of thrombi has been reported pathologically, it is rarely recognized in clinical practice. Methods Based on histopathologic features, recanalization of thrombi was defined by characteristics on OCT. Results Recanalization of thrombi was identified in 6 patients (3 male, 3 female; median age 63 years; age range 54 to 72 years). Based on symptoms, 3 patients were diagnosed with unstable angina; 2 were diagnosed with stable angina; and 1, who had mitral stenosis and ...

Abstract  Recent advances in intra-coronary imaging modalities have enabled us to evaluate precise plaque morphologies and vascular response to coronary stents in vivo. Superior resolution of optical coherence tomography (OCT) allows the measurement of fibrous cap thickness and detection of macrophage accumulation, both of which are critical to identify vulnerable plaques. Poor penetration of OCT however limits the assessment of plaque volume and vessel remodeling, while intravascular ultrasound (IVUS) is capable of evaluating these parameters. Caution must be exercised when interpreting IVUS-based tissue characterization because this technology lacks sufficient resolution to evaluate plaque composition. In stented arteries, OCT has the ...

Introduction This document is complementary to an Expert Review Document on Optical Coherence Tomography (OCT) for the study of coronary arteries and atherosclerosis.1 The goal of this companion manuscript is to provide a practical guide framework for the appropriate use and reporting of the novel frequency domain (FD) OCT imaging to guide interventional procedures, with a particular interest on the comparison with intravascular ultrasound (IVUS).1–4 Technique for optical coherence tomography imaging In the OCT Expert Review Document on Atherosclerosis, a comprehensive description of the physical principles for OCT imaging and time domain (TD) catheters (St Jude Medical ...

Objectives: The purpose of this document is to make the output of the International Working Group for Intravascular Optical Coherence Tomography (IWG-IVOCT) Standardization and Validation available to medical and scientific communities, through a peer-reviewed publication, in the interest of improving the diagnosis and treatment of patients with atherosclerosis, including coronary artery disease.Background: Intravascular optical coherence tomography (IVOCT) is a catheter-based modality that acquires images at a resolution of 10 μm, enabling visualization of blood vessel wall microstructure in vivo at an unprecedented level of detail. IVOCT devices are now commercially available worldwide, there is an active user base, and ...

The diagnosis of acute coronary syndrome (ACS) is primarily based on the mode of clinical presentation and is a term used for any conditions suggesting the acute induction of myocardial ischemia. The precise molecular and cellular triggers that lead to ACS remain poorly understood; however, histopathologic studies have illustrated several mechanisms that may explain the sudden onset of symptoms in ACS patients. The most common substrate underlying ACS is thought to be rupture of a vulnerable plaque that contains a necrotic core covered by a fibrous cap. The term, thin-cap fibroatheroma (TCFA) is used to describe vulnerable plaque because histomorphometric ...