x-ray tube


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tube

 [to̳b]
a hollow cylindrical organ or instrument. adj., adj tu´bal.
auditory tube eustachian tube.
Blakemore-Sengstaken tube Sengstaken-Blakemore tube.
chest tube see chest tube.
Dobhoff tube a small-lumen feeding tube that can be advanced into the duodenum.
drainage tube a tube used in surgery to facilitate escape of fluids.
Drieling tube a double-lumen tube having a metal weight at one end to carry it past the stomach into the duodenum. At the other end are two tails, one used to collect gastric specimens and the other to collect specimens from the duodenum. The tube is used in the secretin test for pancreatic exocrine function.
Durham's tube a jointed tracheostomy tube.
endobronchial tube a single- or double-lumen tube inserted into the bronchus of one lung and sealed with an inflatable cuff, permitting ventilation of the intubated lung and complete deflation of the other lung; used in anesthesia and thoracic surgery.
endotracheal tube see endotracheal tube.
esophageal tube stomach tube.
eustachian tube see eustachian tube.
Ewald tube a large lumen tube used in gastric lavage.
fallopian tube see fallopian tube.
feeding tube one for introducing high-caloric fluids into the stomach; see also tube feeding.
tube feeding a means of providing nutrition via a feeding tube inserted into the gastrointestinal tract; it may be done to maintain nutritional status over a period of time or as a treatment for malnutrition. It can be used as the only source of nutrition or as a supplement to oral feeding or parenteral nutrition.

Patients who may require tube feeding include those unable to take in an adequate supply of nutrients by mouth because of the side effects of chemotherapy or radiation therapy, those with depression or some other psychiatric disorder, and those suffering from severe hypermetabolic states such as burns or sepsis, or malabsorption syndromes. Other conditions that may require tube feeding include surgery or trauma to the oropharynx, esophageal fistula, and impaired swallowing such as that which occurs following stroke or that related to neuromuscular paralysis.

There are commercially prepared formulas for tube feeding. Some contain all six necessary nutrients (carbohydrates, fats, proteins, vitamins, minerals, and trace elements) and need no supplement as long as they are given in sufficient volume to meet nutritional and caloric needs. Other types of tube feeding formulas are incomplete and therefore will require some supplementation. Choice of formula is based on the patient's particular needs, presence of organ failure or metabolic aberration, lactose tolerance, gastrointestinal function, and how and where the feeding is to be given, that is, via nasogastric, gastrostomy, or enterostomy tube.
Patient Care. In addition to frequent and periodic checking for tube placement and monitoring of gastric residuals to prevent aspiration, other maintenance activities include monitoring effectiveness of the feeding and assessing the patient's tolerance to the tube and the feeding. Special mouth care is essential to maintain a healthy oral mucosa. A summary of the complications related to tube feeding, their causes and contributing factors, and interventions to treat or prevent each complication is presented in the accompanying table.
fermentation tube a U-shaped tube with one end closed, for determining gas production by bacteria.
Levin tube a gastroduodenal catheter of sufficiently small caliber to permit transnasal passage; see illustration.
Two types of nasogastric tubes. From Ignatavicius et al., 1995.
Linton tube a triple-lumen tube with a single balloon used to control hemorrhage from esophageal varices. Once it is positioned under fluoroscopic control and inflated, the balloon exerts pressure against the submucosal venous network at the cardioesophageal junction, thus restricting the flow of blood to the esophageal varices.
Miller-Abbott tube see miller-abbott tube.
Minnesota tube a tube with four lumens, used in treatment of esophageal varices; having a lumen for aspiration of esophageal secretions is its major difference from the sengstaken-blakemore tube.
nasogastric tube see nasogastric tube.
nasotracheal tube an endotracheal tube that passes through the nose.
neural tube the epithelial tube produced by folding of the neural plate in the early embryo.
orotracheal tube an endotracheal tube that passes through the mouth.
otopharyngeal tube eustachian tube.
Rehfuss tube a single-lumen oral tube used to obtain specimens of biliary secretions for diagnostic study; it is weighted on one end so that it can be passed through the mouth and positioned at the point where the bile duct empties into the duodenum. See also biliary drainage test.
Salem sump tube a double-lumen nasogastric tube used for suction and irrigation of the stomach. One lumen is attached to suction for the drainage of gastric contents and the second lumen is an air vent. See illustration.
Sengstaken-Blakemore tube see sengstaken-blakemore tube.
stomach tube see stomach tube.
T-tube one shaped like the letter T and inserted into the biliary tract to allow for drainage of bile; it is generally left in place for 10 days or more in order to develop a tract through which bile can drain after the tube is removed. A T-tube cholangiogram is usually performed prior to removal of the tube in order to determine that the common duct is patent and free of stones. If stones are found they can be removed through the tube tract by instruments inserted under x-ray guidance.
test tube a tube of thin glass, closed at one end; used in chemical tests and other laboratory procedures.
thoracostomy tube a tube inserted through an opening in the chest wall, for application of suction to the pleural cavity; used to drain fluid or blood or to reexpand the lung in pneumothorax. See also chest tube.
tracheal tube endotracheal tube.
tracheostomy tube a curved endotracheal tube that is inserted into the trachea through a tracheostomy; see discussion under tracheostomy.
tympanostomy tube ventilation tube.
uterine tube fallopian tube.
ventilation tube a tube inserted after myringotomy in chronic cases of middle ear effusion, such as in secretory or mucoid otitis media; it provides ventilation and drainage for the middle ear during healing, and is eventually extruded. Called also tympanostomy tube.
Tympanostomy (ventilation) tube. Polyethylene tubes are inserted surgically into the eardrum to relieve middle ear pressure and promote drainage of chronic or recurrent middle ear infections. Tubes extrude spontaneously in 6 months to 1 year. From Jarvis, 1996.
Wangensteen tube a small nasogastric tube connected with a special suction apparatus to maintain gastric and duodenal decompression.
Whelan-Moss T-tube a t-tube whose crossbar tube is larger in diameter than the drainage tube.
x-ray tube a glass vacuum bulb containing two electrodes; electrons are obtained either from gas in the tube or from a heated cathode. When suitable potential is applied, electrons travel at high velocity from cathode to anode, where they are suddenly arrested, giving rise to x-rays.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

x-ray

(eks'rā),
1. The ionizing electromagnetic radiation emitted from a highly evacuated tube, resulting from the excitation of the inner orbital electrons by the bombardment of the target anode with a stream of electrons from a heated cathode. Synonym(s): roentgen ray Compare: glass rays, indirect rays.
2. Ionizing electromagnetic radiation produced by the excitation of the inner orbital electrons of an atom by other processes, such as nuclear delay and its sequelae.
3. Synonym(s): radiograph
Farlex Partner Medical Dictionary © Farlex 2012

x-ray tube

(rā tūb)
Vacuum tube containing electrodes that are directed onto a metal target to produce an x-ray.
See also: x-ray
Medical Dictionary for the Dental Professions © Farlex 2012
References in periodicals archive ?
The target style of the x-ray tube in an electronics x-ray system impacts magnification, resolution and flux.
"Study of a resonant converter using power transistor in a 25kW X-ray tube power supply." Proc.
In 1970, Varian EIMAC began manufacturing X-ray tubes in the Salt Lake City at its current facility on Pioneer Road.
The dose levels to the neurosurgeon were measured on both sides of the C-arm, X-ray tube (tube) or image intensifier (II).
The accelerating potential is the applied voltage between the anode and cathode of the x-ray tube. Electrons are produced at the cathode and accelerated striking the target anode creating x-rays.
Oblique viewing capability can be achieved by moving the system image-capture device, in some way, into an oblique angle relative to the plane of the x-ray tube and sample.
This position yields equivalent results without the need to angle or horizontally place the x-ray tube. This eliminates the need for an apparatus to hold the cassette.
Coauthor Timm Weitkamp of the European Synchrotron Radiation Facility in Grenoble, France, says the new gratings can handle the less intense, multiwavelength, and multidirectional beams that emerge from typical hospital X-ray tubes.
Smaller x-ray tubes have replaced traditional radioisotope sources in the analyzers, allowing not only faster measurements, but also more precise ones.
In most cases, these systems use an anticollision system (ACS), making collision between samples and the X-ray tube impossible.
Its performance for light element analysis is based on optimal excitation at a maximum of 150 mA, combined with the 75 micron ultra thin x-ray tube window, a broad selection of intensely optimised multilayer crystal and collimator combinations, and the application of super high transmission detector window materials.
Patent 6,269,144 was recently issued to NIST for a "Method and Apparatus for Diffraction Measurement Using a Scanning X-ray Source." The concept combines the high-energy X-ray diffraction technology that has been developed by NIST during the past 5 years with the unique area-scanned X-ray tube developed by a private company.