A modern fluoroscope.

Fluoroscopy is an imaging technique commonly used by physicians to obtain real-time images of the internal structures of a patient through the use of a fluoroscope. In its simplest form, a fluoroscope consists of an x-ray source and fluorescent screen between which a patient is placed. However, modern fluoroscopes couple the screen to an x-ray image intensifier and CCD video camera allowing the images to be played and recorded on a monitor. The use of x rays, a form of ionizing radiation, requires that the potential risks from a procedure be carefully balanced with the benefits of the procedure to the patient. While physicians always try to use low dose rates during fluoroscopy procedures, the length of a typical procedure often results in a relatively high absorbed dose to the patient. Recent advances include the digitization of the images captured and flat-panel detector systems which reduce the radiation dose to the patient still further. Image File history File links A modern fluoroscope. ... Image File history File links A modern fluoroscope. ... The word physician should not be confused with physicist, which means a scientist in the area of physics. ... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz... An X-ray image intensifier (XRII) refers to a special image intensifier device used in medical imaging involving x rays. ... A specially developed CCD used for ultraviolet imaging in a wire bonded package. ... A video camera can be classified two ways: Professional video cameras, such as those used in television production Camcorders used by amateurs This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz... Ionizing radiation has many practical uses, but it is also dangerous to human health. ... Dose can refer to several things: An amount of medication to be taken at one time. ... Absorbed dose is a measure of the energy deposited in a medium by ionising radiation. ...

History

The beginning of fluoroscopy can be traced back to 8 November 1895 when Wilhelm Röntgen noticed a barium platinocyanide screen fluorescing as a result of being exposed to what he would later call x rays. Within months of this discovery, the first fluoroscopes were created. Thomas Edison quickly discovered that calcium tungstate screens produced brighter images and is credited with designing and producing the first commercially available fluoroscope. In its infancy, many incorrectly predicted that the moving images from fluoroscopy would completely replace the still x-ray radiographs, but the superior diagnostic quality of the earlier radiographs prevented this from occurring. November 8 is the 312th day of the year (313th in leap years) in the Gregorian Calendar, with 53 days remaining. ... 1895 (MDCCCXCV) was a common year starting on Tuesday (see link for calendar) of the Gregorian calendar (or a common year starting on Thursday of the 12-day-slower Julian calendar). ... Wilhelm Röntgen Wilhelm Conrad Röntgen (March 27, 1845 – February 10, 1923) was a German physicist, of the University of Würzburg, who, on November 8, 1895, produced wavelengths of electromagnetic radiation that are now known as x-rays or Röntgen Rays. ... General Name, Symbol, Number barium, Ba, 56 Chemical series alkaline earth metals Group, Period, Block 2, 6, s Appearance silvery white Atomic mass 137. ... In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz... Thomas Alva Edison (February 11, 1847 – October 18, 1931) was an American inventor and businessman who developed many devices which greatly influenced life in the 20th century. ... Scheelite is a calcium tungstate mineral with the chemical formula CaWO4. ... Radiography is the creation of radiographs, photographs made by exposing a photographic film or other image receptor to X-rays. ...

Ignorance of the harmful effects of x rays resulted in the absence of standard radiation safety procedures which are employed today. Scientists and physicians would often place their hands directly in the x-ray beam resulting in radiation burns. Trivial uses for the technology also resulted, including the Shoe-Fitting Fluoroscope used by shoe stores in the 1930s-1950s.[1] In the NATO phonetic alphabet, X-ray represents the letter X. An X-ray picture (radiograph) taken by Röntgen An X-ray is a form of electromagnetic radiation with a wavelength approximately in the range of 5 pm to 10 nanometers (corresponding to frequencies in the range 30 PHz... A radiation burn is damage to the skin or other biological tissue caused by exposure to ionizing radiation. ... Shoe-Fitting Fluoroscopes were X-ray machines installed in shoe stores from the early 20th century up until about 1960 in the USA by which time they had been prohibited, and into the mid-1970s in the UK. In the UK, they were known as Pedoscopes, after the company... 1930 (MCMXXX) was a common year starting on Wednesday (link is to a full 1930 calendar). ... 1950 (MCML) was a common year starting on Sunday (link will take you to calendar). ...

Due to the limited light produced from the fluorescent screens, early radiologists were required to sit in a darkened room, in which the procedure was to be performed, accustomizing their eyes to the dark and thereby increasing their sensitivity to the light. The placement of the radiologist behind the screen resulted in significant radiation doses to the radiologist. Red adaptation goggles were developed by Wilhelm Trendelenburg in 1916 to address the problem of dark adaptation of the eyes, previously studied by Antoine Beclere. The resulting red light from the goggles' filtration correctly sensitized the physician's eyes prior to the procedure while still allowing him to receive enough light to function normally. Radiology is the branch of medical science dealing with the medical use of x-ray machines or other such radiation devices for the purpose of obtaining visual information as part of medical imaging. ... Absorbed dose is a measure of the energy deposited in a medium by ionising radiation. ... Red adaptation goggles were first invented by Wilhem Trendleenburg in 1916 for early radiologists to use to adapt their eyes to view the light produced by fluorescent screens during fluoroscopic procedures. ... 1916 (MCMXVI) was a leap year starting on Saturday (link will take you to calendar). ... The Purkinje effect (sometimes called the Purkinje shift, or dark adaptation) is the tendency for the peak sensitivity of the human eye to shift toward the blue end of the color spectrum at low illumination levels. ...

The development of the X-ray image intensifier and the television camera in the 1950s revolutionized fluoroscopy. The red adaptation goggles became obsolete as image intensifiers allowed the light produced by the fluorescent screen to be amplified, allowing it to be seen even in a lighted room. The addition of the camera enabled viewing of the image on a monitor, allowing a radiologist to view the images in a separate room away from the risk of radiation exposure. An X-ray image intensifier (XRII) refers to a special image intensifier device used in medical imaging involving x rays. ... A professional video camera (often called a television camera even though the use has spread) is a high-end device for recording electronic moving images (as opposed to a movie camera, that records the images on film). ... 1950 (MCML) was a common year starting on Sunday (link will take you to calendar). ... Red adaptation goggles were first invented by Wilhem Trendleenburg in 1916 for early radiologists to use to adapt their eyes to view the light produced by fluorescent screens during fluoroscopic procedures. ... A camera is a device used to capture images, usually photographs, either singly or in sequence such as with video cameras. ... The radiation warning symbol (trifolium). ...

More modern improvements in screen phosphors, image intensifiers and even flat panel detectors have allowed for increased image quality while minimizing the radiation dose to the patient. Modern fluoroscopes use CsI screens and produce noise-limited images, ensuring that the minimal radiation dose results while still obtaining images of acceptable quality. A phosphor is a substance that can exhibit the phenomenon of fluorescence (glowing during absorption of radiation of another kind) or phosphorescence (sustained glowing without further stimulus). ... Caesium iodide is an ionic compound often used as the input phosphor of an x-ray image intensifier tubes found in Fluoroscopy equipment. ...

Risks

Because fluoroscopy involves the use of x rays, a form of ionizing radiation, all fluoroscopic procedures pose a potential health risk to the patient. Radiation doses to the patient depend greatly on the size of the patient as well as length of the procedure, with typical skin dose rates quoted as 20-50 mGy/min. Exposure times vary depending on the procedure being performed, but procedure times up to 75 minutes have been documented. Because of the long length of some procedures, in addition to standard cancer-inducing stochastic radiation effects, deterministic radiation effects have also been observed ranging from mild erythema, equivalent of a sun burn, to more serious burns. Ionizing radiation has many practical uses, but it is also dangerous to human health. ... The gray (symbol: Gy) is the SI unit of absorbed dose. ... Cancer is a class of diseases or disorders characterized by uncontrolled division of cells and the ability of these cells to invade other tissues, either by direct growth into adjacent tissue through invasion or by implantation into distant sites by metastasis. ... Erythema is an abnormal redness of the skin caused by capillary congestion. ... A sunburn is a radiation burn to the skin produced by overexposure to ultraviolet (UV) light, commonly from the suns rays. ...

A study has been performed by the Food and Drug Administration (FDA) entitled Radiation-induced Skin Injuries from Fluoroscopy[2] with an additional publication to minimize further fluoroscopy-induced injuries, Public Health Advisory on Avoidance of Serious X-Ray-Induced skin Injuries to Patients During Fluoroscopically-Guided Procedures[3]. The Food and Drug Administration (FDA) is an agency of the United States Department of Health and Human Services and is responsible for regulating food (humans and animal), dietary supplements, drugs (human and animal), cosmetics, medical devices (human and animal) and radiation emitting devices (including non-medical devices), biologics, and...

While deterministic radiation effects are a possibility, radiation burns are not typical of standard fluoroscopic procedures. Most procedures sufficiently long in length to produce radiation burns are part of necessary life-saving operations. A radiation burn is damage to the skin or other biological tissue caused by exposure to ionizing radiation. ...

Fluoroscope design

The first fluoroscopes consisted of an x-ray source and fluorescent screen between which the patient would be placed. As the x rays pass through the patient, they are attenuated by varying amounts as they interact with the different internal structures of the body, casting a shadow of the structures on the fluorescent screen. Images on the screen are produced as the unattenuated x rays interact with atoms in the screen through the photoelectric effect, giving their energy to the electrons. While much of the energy given to the electrons is dissipated as heat, a fraction of it is given off as visible light, producing the images. Early radiologists would adapt their eyes to view the dim fluoroscopic images by sitting in darkened rooms, or by wearing red adaptation goggles. Attenuation is the decrease in intensity of electromagnetic radiation due to absorption or scattering of photons. ... Shadows on a pavement A shadow is a region of darkness where light is blocked. ... The photoelectric effect is the emission of electrons from matter upon the absorption of electromagnetic radiation, such as ultraviolet radiation or x-rays. ... Properties The electron (also called negatron, commonly represented as e−) is a subatomic particle. ... The Electron is a fundamental subatomic particle that carries an electric charge. ... In physics, heat, symbolized by Q, is defined as energy in transit. ... Radiology is the branch of medical science dealing with the medical use of x-ray machines or other such radiation devices for the purpose of obtaining visual information as part of medical imaging. ... Red adaptation goggles were first invented by Wilhem Trendleenburg in 1916 for early radiologists to use to adapt their eyes to view the light produced by fluorescent screens during fluoroscopic procedures. ...

X-ray Image Intensifiers

The invention of X-ray image intensifiers in the 1950s allowed the image on the screen to be visible under normal lighting conditions, as well as providing the option of recording the images with a conventional camera. Subsequent improvements included the coupling of, at first, video cameras and, later, CCD cameras to permit recording of moving images and electronic storage of still images. An X-ray image intensifier (XRII) refers to a special image intensifier device used in medical imaging involving x rays. ... 1950 (MCML) was a common year starting on Sunday (link will take you to calendar). ... A specially developed CCD used for ultraviolet imaging in a wire bonded package. ...

Modern image intensifiers no longer use a separate fluorescent screen. Instead, a cesium iodide phosphor is deposited directly on the photocathode of the intensifier tube. On a typical general purpose system, the output image is approximately 10⁵ times brighter than the input image. This brightness gain is comprised of a flux gain (amplification of photon number) and minification gain (concentration of photons from a large input screen onto a small output screen) each of approximately 100. This level of gain is sufficient that quantum noise, due to the limited number of x-ray photons, is a signficant factor limiting image quality. Caesium iodide is an ionic compound often used as the input phosphor of an x-ray image intensifier tubes found in Fluoroscopy equipment. ... Shot noise consists of random fluctuations of the electric current in an electrical conductor, which are caused by the fact that the current is carried by discrete charges (electrons). ...

Image intensifiers are available with input diameters of up to 45 cm, and a resolution of approximately 2-3 line pairs mm^-1.

Flat-panel detectors

The introduction of flat-panel detectors allows for the replacement of the image intensifier in fluoroscope design. Flat panel detectors offer increased sensitivity to X-rays, and therefore have the potential to reduce patient radiation dose. Temporal resolution is also improved over image intensifiers, reducing motion blurring. Contrast ratio is also improved over image intensifiers: flat-panel detectors are linear over a very wide latitude, whereas image intensifiers have a maximum contrast ratio of about 35:1. Spatial resolution is approximately equal, although an image intensifier operating in 'magnification' mode may be slightly better than a flat panel.

Flat panel detectors are considerably more expensive than image intensifiers, so their uptake is primarily in specialties that require high-speed imaging, e.g., vascular imaging and cardiac catheterization. Angiography or arteriography is a medical imaging technique in which an X-ray picture is taken to visualize the inner opening of blood filled structures, including arteries, veins and the heart chambers. ... Cardiac catheterization (heart cath) is the insertion of a catheter into a chamber or vessel of the heart. ...

Imaging concerns

In addition to spatial blurring factors that plague all x-ray imaging devices, caused by such things as Lubberts effect, K-fluorescence reabsorption and electron range, fluoroscopic systems also experience temporal blurring due to system lag. This temporal blurring has the effect of averaging frames together. While this helps reduce noise in images with stationary objects, it creates motion blurring for moving objects. Temporal blurring also complicates measurements of system performance for fluoroscopic systems. Lubberts effect refers to the non-uniform response of an imaging system to x-rays that are absorbed at different depths within the input phosphor. ... The Electron is a fundamental subatomic particle that carries an electric charge. ... Lag often refers to delays experienced in computing communications, however it may also apply to written or other forms of communication. ... This section needs to be cleaned up to conform to a higher standard of quality. ...

Common procedures involving the use of fluoroscopy

• Investigations of the gastrointestinal tract, including Barium enemas, barium meals and barium swallows, and enteroclysis.
• Orthopaedic surgery to guide fracture reduction and the placement of metalwork.
• Angiography of the leg, heart and cerebral vessels.
• Urological surgery – particularly in retrograde pyelography.
• Implantation of Cardiac Rhythm Management devices (Pacemakers, Implantable Cardioverter Defibrillators and Cardiac Resynchronization Devices)

The gastrointestinal tract or digestive tract, also referred to as the GI tract or the alimentary canal, (nourishment canal) or the gut, is the system of organs within multicellular animals which takes in food, digests it to extract energy and nutrients, and expels the remaining waste. ... A barium enema, also called a lower gastrointestinal series, is a medical procedure used to examine and dignose problems with the human large intestines. ... Preprepared Barium Sulfate suspension for oral consumption A barium meal is a procedure in which barium sulfate is ingested by a patient and, in conjunction with X-rays, images depicting the digestive system: the distal esophagus, stomach and duodenum, are obtained. ... A barium meal is a procedure in which barium barium sulfate is ingested by a patient and, in conjunction with X-rays, images depicting the the distal esophagus, stomach and duodenum can be obtained digestive system. ... Enteroclysis is a fluoroscopic X-ray of the small intestine. ... Orthopedic surgery or orthopedics (BE: orthopaedics) is the branch of surgery concerned with acute, chronic, traumatic and recurrent injuries and other disorders of the locomotor system, its musclular and bone parts. ... Angiography or arteriography is a medical imaging technique in which an X-ray picture is taken to visualize the inner opening of blood filled structures, including arteries, veins and the heart chambers. ... Urology is the field of medicine that focuses on the urinary tracts of males and females, and on the reproductive system of males. ... It has been suggested that this article or section be merged with Urography. ... A pacemaker (sometimes called a pacer) is a competitor who enters an athletics race with little or no intention of winning, but purely to set a fast pace for other competitors to follow. ...

See also

• Absorbed dose
• X-ray image intensifier
• Ionizing radiation
• Medical Imaging
• X Ray
• Radiology
• Radiography

Another common procedure performed under fluoroscopy is the modified barium swallow study during which thin liquids, nectar and honey thick liquids, puree and regular solid consistencies are impregnated with barium and ingested by the patient. A speech language pathologist in conjunction with the radiologist records and interprets the resulting images to definitively diagnose oral and pharyngeal swallowing dysfunction, determine safest and most efficient diet consistencies, and plan a direct treatment program for the patient in order to improve outcomes. Absorbed dose is a measure of the energy deposited in a medium by ionising radiation. ... An X-ray image intensifier (XRII) refers to a special image intensifier device used in medical imaging involving x rays. ... Ionizing radiation has many practical uses, but it is also dangerous to human health. ... It has been suggested that this article or section be merged into Radiology. ... An X-ray picture (radiograph), taken by Wilhelm Röntgen, of Albert von Köllikers hand. ... Image A: A normal chest X-ray. ... Radiography is the creation of images by exposing a photographic film or other image receptor to X-rays. ...

External links

• "Were those old shoe store fluoroscopes a health hazard?" at Straight Dope, 27 November 1987

• - Fluoroscopy Equipment and Information from Siemens Medical