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Venography
Venography (also called phlebography or ascending phlebography) is a procedure in which an X-ray of the veins, a venogram, is taken after a special dye is injected into the bone marrow or veins. The dye has to be injected constantly via a catheter, making it an invasive procedure. Normally the catheter is inserted by the groin and moved to the appropriate site by navigating through the vascular system. Contrast venography is the gold standard for judging diagnostic imaging methods for deep vein thrombosis; although, because of its cost, invasiveness, and other limitations, this test is rarely performed. Venography can also be used to distinguish blood clots from obstructions in the veins, to evaluate congenital vein problems, to see how the deep leg vein valves are working, or to identify a vein for arterial bypass grafting. Areas of the venous system that can be investigated include the lower extremities, the inferior vena cava, and the upper extremities. The United States Na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vein
Veins () are blood vessels in the circulatory system of humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are those of the pulmonary and fetal circulations which carry oxygenated blood to the heart. In the systemic circulation, arteries carry oxygenated blood away from the heart, and veins return deoxygenated blood to the heart, in the deep veins. There are three sizes of veins: large, medium, and small. Smaller veins are called venules, and the smallest the post-capillary venules are microscopic that make up the veins of the microcirculation. Veins are often closer to the skin than arteries. Veins have less smooth muscle and connective tissue and wider internal diameters than arteries. Because of their thinner walls and wider lumens they are able to expand and hold more blood. This greater capacity gives them the term of ''capacitance vessels''. At any time, nearly 70% o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Venous Valves
Veins () are blood vessels in the circulatory system of humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are those of the pulmonary and fetal circulations which carry oxygenated blood to the heart. In the systemic circulation, arteries carry oxygenated blood away from the heart, and veins return deoxygenated blood to the heart, in the deep veins. There are three sizes of veins: large, medium, and small. Smaller veins are called venules, and the smallest the post-capillary venules are microscopic that make up the veins of the microcirculation. Veins are often closer to the skin than arteries. Veins have less smooth muscle and connective tissue and wider internal diameters than arteries. Because of their thinner walls and wider lumens they are able to expand and hold more blood. This greater capacity gives them the term of ''capacitance vessels''. At any time, nearly 70% of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deep Vein Thrombosis
Deep vein thrombosis (DVT) is a type of venous thrombosis involving the formation of a blood clot in a deep vein, most commonly in the legs or pelvis. A minority of DVTs occur in the arms. Symptoms can include pain, swelling, redness, and enlarged veins in the affected area, but some DVTs have no symptoms. The most common life-threatening concern with DVT is the potential for a clot to embolize (detach from the veins), travel as an embolus through the right side of the heart, and become lodged in a pulmonary artery that supplies blood to the lungs. This is called a pulmonary embolism (PE). DVT and PE comprise the cardiovascular disease of venous thromboembolism (VTE). About two-thirds of VTE manifests as DVT only, with one-third manifesting as PE with or without DVT. The most frequent long-term DVT Complication (medicine), complication is post-thrombotic syndrome, which can cause pain, swelling, a sensation of heaviness, itching, and in severe cases, ulcers. Recurrent VTE o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Subtraction Angiography
Digital subtraction angiography (DSA) is a fluoroscopy technique used in interventional radiology to clearly visualize blood vessels in a bony or dense soft tissue environment. Images are produced using contrast medium by subtracting a "pre-contrast image" or ''mask'' from subsequent images, once the contrast medium has been introduced into a structure. Hence the term "digital ''subtraction'' angiography. Subtraction angiography was first described in 1935 and in English sources in 1962 as a manual technique. Digital technology made DSA practical starting in the 1970s. Procedure DSA and fluoroscopy In traditional angiography, images are acquired by exposing an area of interest with time-controlled x-rays while injecting a contrast medium into the blood vessels. The image obtained includes the blood vessels, together with all overlying and underlying structures. The images are useful for determining anatomical position and variations, but unhelpful for visualizing blood vessels a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phlebitis
Phlebitis (or venitis) is inflammation of a vein, usually in the legs. It most commonly occurs in superficial veins. Phlebitis often occurs in conjunction with thrombosis (clotting inside blood vessels) and is then called thrombophlebitis or superficial thrombophlebitis. Unlike deep vein thrombosis, the probability that superficial thrombophlebitis will cause a clot to break up and be transported in pieces to the lung is very low. Signs and symptoms * Localized redness and swelling * Pain or burning along the length of the vein * Vein being hard and cord-like There is usually a slow onset of a tender red area along the superficial veins on the skin. A long, thin red area may be seen as the inflammation follows a superficial vein. This area may feel hard, warm, and tender. The skin around the vein may be itchy and swollen. The area may begin to throb or burn. Symptoms may be worse when the leg is lowered, especially when first getting out of bed in the morning. A low-grade ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Femoral Vein
In the human body, the femoral vein is the vein that accompanies the femoral artery in the femoral sheath. It is a deep vein that begins at the adductor hiatus (an opening in the adductor magnus muscle) as the continuation of the popliteal vein. The great saphenous vein (a superficial vein), and the deep femoral vein drain into the femoral vein in the femoral triangle when it becomes known as the common femoral vein. It ends at the inferior margin of the inguinal ligament where it becomes the external iliac vein. Its major tributaries are the deep femoral vein, and the great saphenous vein. The femoral vein contains valves. Structure The femoral vein bears valves which are mostly bicuspid and whose number is variable between individuals and often between left and right leg. Course The femoral vein continues into the thigh as the continuation from the popliteal vein at the back of the knee. It drains blood from the deep thigh muscles and thigh bone. Proximal to th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valsalva Maneuver
The Valsalva maneuver is performed by a forceful attempt of exhalation against a closed airway, usually done by closing one's mouth and pinching one's nose shut while expelling air, as if blowing up a balloon. Variations of the maneuver can be used either in medicine, medical examination as a test of cardiac function and autonomic nervous system, autonomic nervous control of the heart (because the maneuver raises the pressure in the lungs), or to clear the ears and paranasal sinuses, sinuses (that is, to equalize pressure between them) when ambient pressure changes, as in scuba diving, hyperbaric oxygen therapy, or air travel. A modified version is done by expiring against a closed glottis. This will elicit the cardiovascular responses described below but will not force air into the Eustachian tubes. History The technique is named after Antonio Maria Valsalva, a 17th-century physician and anatomist from Bologna whose principal scientific interest was the human ear. He descri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anterior Tibial Vein
The anterior tibial vein is a vein in the lower leg. In human anatomy, there are two anterior tibial veins. They originate and receive blood from the dorsal venous arch, on the back of the foot and empties into the popliteal vein. The anterior tibial veins drain the ankle joint, knee joint, tibiofibular joint, and the anterior portion of the lower leg. The two anterior tibial veins ascend in the interosseous membrane between the tibia and fibula and unite with the posterior tibial veins to form the popliteal vein. Like most deep veins in legs, anterior tibial veins are accompanied by the homonym artery An artery () is a blood vessel in humans and most other animals that takes oxygenated blood away from the heart in the systemic circulation to one or more parts of the body. Exceptions that carry deoxygenated blood are the pulmonary arteries in ..., the anterior tibial artery, along its course. References Veins of the lower limb {{Circulatory-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superficial Vein
Superficial veins are veins that are close to the surface of the body, as opposed to deep veins, which are far from the surface. Superficial veins are not paired with an artery, unlike the deep veins, which are typically associated with an artery of the same name. Superficial veins are important physiology, physiologically for cooling of the body. When the body is too hot, the body shunts blood from the deep veins to the superficial veins to facilitate heat transfer to the body's surroundings. Superficial veins are often visible underneath the skin. Those below the level of the heart tend to bulge out, which can be readily witnessed in the hand, where the veins bulge significantly less after the arm has been raised above the head for a short time. Veins become more visually prominent when lifting heavy weight, especially after a period of proper strength training. Physiologically, the superficial veins are not as important as the deep veins (as they carry less blood) and ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Contrast Agent
A contrast agent (or contrast medium) is a substance used to increase the contrast of structures or fluids within the body in medical imaging. Contrast agents absorb or alter external electromagnetism or ultrasound, which is different from radiopharmaceuticals, which emit radiation themselves. In X-ray imaging, contrast agents enhance the radiodensity in a target tissue or structure. In magnetic resonance imaging (MRI), contrast agents shorten (or in some instances increase) the relaxation times of nuclei within body tissues in order to alter the contrast in the image. Contrast agents are commonly used to improve the visibility of blood vessels and the gastrointestinal tract. The types of contrast agent are classified according to their intended imaging modalities. Radiocontrast media For radiography, which is based on X-rays, iodine and barium are the most common types of contrast agent. Various sorts of iodinated contrast agents exist, with variations occurring between the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sepsis
Sepsis is a potentially life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage of sepsis is followed by suppression of the immune system. Common signs and symptoms include fever, tachycardia, increased heart rate, hyperventilation, increased breathing rate, and mental confusion, confusion. There may also be symptoms related to a specific infection, such as a cough with pneumonia, or dysuria, painful urination with a pyelonephritis, kidney infection. The very young, old, and people with a immunodeficiency, weakened immune system may not have any symptoms specific to their infection, and their hypothermia, body temperature may be low or normal instead of constituting a fever. Severe sepsis may cause organ dysfunction and significantly reduced blood flow. The presence of Hypotension, low blood pressure, high blood Lactic acid, lactate, or Oliguria, low urine output may suggest poor blood flow. Se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
