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IVUS
Intravascular ultrasound (IVUS) or intravascular echocardiography is a medical imaging methodology using a specially designed catheter with a miniaturized ultrasound probe attached to the distal end of the catheter. The proximal end of the catheter is attached to computerized ultrasound equipment. It allows the application of ultrasound technology, such as piezoelectric transducer or CMUT, to see from inside blood vessels out through the surrounding blood column, visualizing the endothelium (inner wall) of blood vessels. The arteries of the heart (the coronary arteries) are the most frequent imaging target for IVUS. IVUS is used in the coronary arteries to determine the amount of atheromatous plaque built up at any particular point in the epicardial coronary artery. Intravascular ultrasound provides a unique method to study the regression or progression of atherosclerotic lesions in vivo. The progressive accumulation of plaque within the artery wall over decades leads to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echocardiogram
Echocardiography, also known as cardiac ultrasound, is the use of ultrasound to examine the heart. It is a type of medical imaging, using standard ultrasound or Doppler ultrasound. The visual image formed using this technique is called an echocardiogram, a cardiac echo, or simply an echo. Echocardiography is routinely used in the diagnosis, management, and follow-up of patients with any suspected or known heart diseases. It is one of the most widely used diagnostic imaging modalities in cardiology. It can provide a wealth of helpful information, including the size and shape of the heart (internal chamber size quantification), pumping capacity, location and extent of any tissue damage, and assessment of valves. An echocardiogram can also give physicians other estimates of heart function, such as a calculation of the cardiac output, ejection fraction, and diastolic function (how well the heart relaxes). Echocardiography is an important tool in assessing wall motion abnormality ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Percutaneous Coronary Intervention
Percutaneous coronary intervention (PCI) is a minimally invasive non-surgical procedure used to treat stenosis, narrowing of the coronary artery, coronary arteries of the heart found in coronary artery disease. The procedure is used to place and deploy coronary stents, a permanent wire-meshed tube, to open narrowed coronary arteries. PCI is considered 'non-surgical' as it uses a small hole in a peripheral artery (leg/arm) to gain access to the arterial system; an equivalent surgical procedure would involve the opening of the chest wall to gain access to the heart area. The term 'coronary angioplasty with stent' is synonymous with PCI. The procedure visualises the blood vessels via Fluoroscopy, fluoroscopic imaging and contrast dyes. PCI is performed by an interventional cardiologists in a catheterization laboratory setting. Patients who undergo PCI broadly fall into two patient groups. Those who are suffering from a heart attack and are in a critical care emergency room setting an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atheroma
An atheroma, or atheromatous plaque, is an abnormal accumulation of material in the tunica intima, inner layer of an arterial wall. The material consists of mostly macrophage, macrophage cells, or debris, containing lipids, calcium and a variable amount of fibrous connective tissue. The accumulated material forms a swelling in the artery wall, which may intrude into the Lumen (anatomy), lumen of the artery, stenosis, narrowing it and restricting blood flow. Atheroma is the pathological basis for the disease entity atherosclerosis, a subtype of arteriosclerosis. Signs and symptoms For most people, the first symptoms result from atheroma progression within the coronary arteries, heart arteries, most commonly resulting in a myocardial infarction, heart attack and ensuing debility. The heart arteries are difficult to track because they are small (from about 5 mm down to microscopic), they are hidden deep within the chest and they never stop moving. Additionally, all mass-applie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capacitive Micromachined Ultrasonic Transducers
Capacitive micromachined ultrasonic transducers (CMUT) are a relatively new concept in the field of ultrasonic transducers. Most of the commercial ultrasonic transducers today are based on piezoelectricity. In CMUTs, the energy transduction is due to change in capacitance. CMUTs are constructed on silicon using micromachining techniques. A cavity is formed in a silicon substrate, and a thin layer suspended on the top of the cavity serves as a membrane on which a metallized layer acts an electrode, together with the silicon substrate which serves as a bottom electrode. If an AC signal is applied across the biased electrodes, the vibrating membrane will produce ultrasonic waves in the medium of interest. In this way it works as a transmitter. On the other hand, if ultrasonic waves are applied on the membrane of a biased CMUT, it will generate alternating signal as the capacitance of the CMUT is varied. In this way, it works as a receiver of ultrasonic waves. As CMUTs are micr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intravascular Optical Coherence Tomography
Endoscopic optical coherence tomography, also intravascular optical coherence tomography is a catheter-based imaging application of optical coherence tomography (OCT). It is capable of acquiring high-resolution images from inside a blood vessel using optical fibers and laser technology. One of its main applications is for coronary arteries, which are often treated by endoscopic, minimally invasive surgical procedures. Other applications for peripheral arteries and for neurovascular procedures have been proposed and are being investigated. Neurovascular applications required significant technological developments, due to the highly tortuous anatomy of the cerebrovasculature. Intravascular OCT rapidly creates three-dimensional images at a resolution of approximately 15 micrometers, an improved resolution with respect to intravascular ultrasound and coronary angiogram, the other imaging techniques. This offers additional information that can be used to optimize the treatment a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atherosclerosis
Atherosclerosis is a pattern of the disease arteriosclerosis, characterized by development of abnormalities called lesions in walls of arteries. This is a chronic inflammatory disease involving many different cell types and is driven by elevated blood levels of cholesterol. These lesions may lead to narrowing of the arterial walls due to buildup of atheromatous plaques. At the onset, there are usually no symptoms, but if they develop, symptoms generally begin around middle age. In severe cases, it can result in coronary artery disease, stroke, peripheral artery disease, or kidney disorders, depending on which body part(s) the affected arteries are located in the body. The exact cause of atherosclerosis is unknown and is proposed to be multifactorial. Risk factors include dyslipidemia, abnormal cholesterol levels, elevated levels of inflammatory biomarkers, high blood pressure, diabetes, smoking (both active and passive smoking), obesity, genetic factors, family history, lifes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vulnerable Plaque
A vulnerable plaque is a kind of atheromatous plaque – a collection of white blood cells (primarily macrophages) and lipids (including cholesterol) in the wall of an artery – that is particularly unstable and prone to produce sudden major problems such as a heart attack or stroke. The defining characteristics of a vulnerable plaque include but are not limited to: a thin fibrous cap, large lipid-rich necrotic core, increased plaque inflammation, positive vascular remodeling, increased vasa-vasorum neovascularization, and intra-plaque hemorrhage. These characteristics together with the usual hemodynamic pulsating expansion during systole and elastic recoil contraction during diastole contribute to a high mechanical stress zone on the fibrous cap of the atheroma, making it prone to rupture. Increased hemodynamic stress, e.g. increased blood pressure, especially pulse pressure (systolic blood pressure vs. diastolic blood pressure difference), correlates with increased rates of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myocardial Infarction
A myocardial infarction (MI), commonly known as a heart attack, occurs when Ischemia, blood flow decreases or stops in one of the coronary arteries of the heart, causing infarction (tissue death) to the heart muscle. The most common symptom is retrosternal Angina, chest pain or discomfort that classically radiates to the left shoulder, arm, or jaw. The pain may occasionally feel like heartburn. This is the dangerous type of acute coronary syndrome. Other symptoms may include shortness of breath, nausea, presyncope, feeling faint, a diaphoresis, cold sweat, Fatigue, feeling tired, and decreased level of consciousness. About 30% of people have atypical symptoms. Women more often present without chest pain and instead have neck pain, arm pain or feel tired. Among those over 75 years old, about 5% have had an MI with little or no history of symptoms. An MI may cause heart failure, an Cardiac arrhythmia, irregular heartbeat, cardiogenic shock or cardiac arrest. Most MIs occur d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stenosis
Stenosis () is the abnormal narrowing of a blood vessel or other tubular organ or structure such as foramina and canals. It is also sometimes called a stricture (as in urethral stricture). ''Stricture'' as a term is usually used when narrowing is caused by contraction of smooth muscle (e.g. achalasia, prinzmetal angina); ''stenosis'' is usually used when narrowing is caused by lesion that reduces the space of lumen (e.g. atherosclerosis). The term coarctation is another synonym, but is commonly used only in the context of aortic coarctation. Restenosis is the recurrence of stenosis after a procedure. Examples Examples of vascular stenotic lesions include: * Intermittent claudication (peripheral artery stenosis) * Angina ( coronary artery stenosis) * Carotid artery stenosis which predispose to (strokes and transient ischaemic episodes) * Renal artery stenosis Types In heart valves The types of stenoses in heart valves are: * Pulmonary valve stenosis, which is th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thrombosis
Thrombosis () is the formation of a Thrombus, blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel (a vein or an artery) is injured, the body uses platelets (thrombocytes) and fibrin to form a blood clot to prevent blood loss. Even when a blood vessel is not injured, blood clots may form in the body under certain conditions. A clot, or a piece of the clot, that breaks free and begins to travel around the body is known as an embolus. Thrombosis can cause serious conditions such as stroke and heart attack. Thrombosis may occur in veins (venous thrombosis) or in arteries (arterial thrombosis). Venous thrombosis (sometimes called DVT, deep vein thrombosis) leads to a blood clot in the affected part of the body, while arterial thrombosis (and, rarely, severe venous thrombosis) affects the blood supply and leads to damage of the tissue supplied by that artery (ischemia and necrosis). A piece of either an arterial or a v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medical Imaging
Medical imaging is the technique and process of imaging the interior of a body for clinical analysis and medical intervention, as well as visual representation of the function of some organs or tissues (physiology). Medical imaging seeks to reveal internal structures hidden by the skin and bones, as well as to diagnose and treat disease. Medical imaging also establishes a database of normal anatomy and physiology to make it possible to identify abnormalities. Although imaging of removed organ (anatomy), organs and Tissue (biology), tissues can be performed for medical reasons, such procedures are usually considered part of pathology instead of medical imaging. Measurement and recording techniques that are not primarily designed to produce images, such as electroencephalography (EEG), magnetoencephalography (MEG), electrocardiography (ECG), and others, represent other technologies that produce data susceptible to representation as a parameter graph versus time or maps that contain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
