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Xeromammography
Xeromammography is a photoelectric method of recording an x-ray image on a coated metal plate, using low-energy photon beams, long Shutter speed, exposure time, and dry Photographic developer, chemical developers. It is a form of xeroradiography. This process was developed in the late 1960s by Jerry Hedstrom, and used to image soft tissue, and later focused on using the process to detect breast cancer. References External linksA Demonstration of Xeromammography [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xeroradiography
Xeroradiography is a type of X-ray imaging in which a picture of the body is recorded on paper rather than on film. In this technique, a plate of selenium, which rests on a thin layer of aluminium oxide, is charged uniformly by passing it in front of a scorotron. The process was developed by engineer Dr. Robert C. McMaster in 1950. As X-ray photon impinges on this amorphous coat of selenium, charges diffuse out, in proportion to energy content of the X-ray. This occurs as a result of wikt:photoconduction, photoconduction. The resulting imprint, in the form of charge distribution on the plate, attracts toner particles, which is then transferred to reusable paper plates. In contrast to conventional X-rays, photographic developers are not needed. Hence the term xeroradiography; 'xero' meaning dry in Greek. It requires more radiation exposure. Historically used in mammography prior to the advent of digital mammography. Xeromammography is a form of xeroradiography. References Ext ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photoelectric
The photoelectric effect is the emission of electrons from a material caused by electromagnetic radiation such as ultraviolet light. Electrons emitted in this manner are called photoelectrons. The phenomenon is studied in condensed matter physics, solid state, and quantum chemistry to draw inferences about the properties of atoms, molecules and solids. The effect has found use in electronic devices specialized for light detection and precisely timed electron emission. The experimental results disagree with classical electromagnetism, which predicts that continuous light waves transfer energy to electrons, which would then be emitted when they accumulate enough energy. An alteration in the intensity of light would theoretically change the kinetic energy of the emitted electrons, with sufficiently dim light resulting in a delayed emission. The experimental results instead show that electrons are dislodged only when the light exceeds a certain frequency—regardless of the light's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-ray
An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ranging from 10 Nanometre, nanometers to 10 Picometre, picometers, corresponding to frequency, frequencies in the range of 30 Hertz, petahertz to 30 Hertz, exahertz ( to ) and photon energies in the range of 100 electronvolt, eV to 100 keV, respectively. X-rays were discovered in 1895 in science, 1895 by the German scientist Wilhelm Röntgen, Wilhelm Conrad Röntgen, who named it ''X-radiation'' to signify an unknown type of radiation.Novelline, Robert (1997). ''Squire's Fundamentals of Radiology''. Harvard University Press. 5th edition. . X-rays can penetrate many solid substances such as construction materials and living tissue, so X-ray radiography is widely used in medical diagnostics (e.g., checking for Bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photon
A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are massless particles that can move no faster than the speed of light measured in vacuum. The photon belongs to the class of boson particles. As with other elementary particles, photons are best explained by quantum mechanics and exhibit wave–particle duality, their behavior featuring properties of both waves and particles. The modern photon concept originated during the first two decades of the 20th century with the work of Albert Einstein, who built upon the research of Max Planck. While Planck was trying to explain how matter and electromagnetic radiation could be in thermal equilibrium with one another, he proposed that the energy stored within a material object should be regarded as composed of an integer number of discrete, equal-sized parts. To explain the pho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shutter Speed
In photography, shutter speed or exposure time is the length of time that the film or digital sensor inside the camera is exposed to light (that is, when the camera's shutter (photography), shutter is open) when taking a photograph. The amount of light that reaches the Photographic film, film or image sensor is proportional to the exposure time. of a second will let half as much light in as . Introduction The camera's shutter speed, the lens's aperture or f-stop, and the scene's luminance together determine the amount of light that reaches the film or sensor (the exposure (photography), exposure). Exposure value (EV) is a quantity that accounts for the shutter speed and the f-number. Once the sensitivity to light of the recording surface (either film or sensor) is set in numbers expressed in "Film speed#ISO, ISOs" (e.g. 200 ISO, 400 ISO), the light emitted by the scene photographed can be controlled through aperture and shutter-speed to match the film or sensor sensitivit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photographic Developer
In the Photographic processing, processing of photographic films, plates or papers, the photographic developer (or just developer) is one or more chemicals that convert the latent image to a visible image. Developing agents achieve this conversion by Redox, reducing the silver halides, which are pale-colored, into silver metal, which is black when in the form of fine particles.Karlheinz Keller et al. ''Photography'' in ''Ullmann's Encyclopedia of Industrial Chemistry'', 2005, Wiley-VCH, Weinheim. . The conversion occurs within the gelatine matrix. The special feature of photography is that the developer acts more quickly on those particles of silver halide that have been exposed to light. When left in developer, all the silver halides will eventually be reduced and turn black. Generally, the longer a developer is allowed to work, the darker the image. Chemical composition of developers The developer typically consists of a mixture of chemical compounds prepared as an aqueous solut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jerry Hedstrom
Jerry may refer to: Animals * Jerry (Grand National winner), racehorse, winner of the 1840 Grand National * Jerry (St Leger winner), racehorse, winner of 1824 St Leger Stakes Arts, entertainment, and media * Jerry (play), a 1914 American play * "Jerry", a song from the album ''Young and Free'' by Rock Goddess * "Jerry" (''Adventure Time: Fionna and Cake''), an episode of the animated television series '' Adventure Time: Fionna and Cake'' * Tom and Jerry (other) ** Jerry Mouse * Jerry, a fictional character who is The Lich BMO named of another universe from ''Adventure Time'' * Jerry (The Walking Dead), a fictional character from The Walking Dead People * Jerry (given name), including a list of people and fictional characters with the name * Harold A. Jerry, Jr. (1920–2001), New York politician * Thomas Jeremiah (d. 1775), commonly known simply as "Jerry", a free Negro in colonial South Carolina * Tyson Jerry (born 1983), a Canadian Guinness World Record holder *Jerr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soft Tissue
Soft tissue connective tissue, connects and surrounds or supports internal organs and bones, and includes muscle, tendons, ligaments, Adipose tissue, fat, fibrous tissue, Lymphatic vessel, lymph and blood vessels, fasciae, and synovial membranes. Soft tissue is Tissue (biology), tissue in the body that is not hard tissue, hardened by the processes of ossification or calcification such as bones and teeth. It is sometimes defined by what it is not – such as "nonepithelial, extraskeletal mesenchyme exclusive of the reticuloendothelial system and glia". Composition The characteristic substances inside the extracellular matrix of soft tissue are the collagen, elastin and ground substance. Normally the soft tissue is very hydrated because of the ground substance. The fibroblasts are the most common cell responsible for the production of soft tissues' fibers and ground substance. Variations of fibroblasts, like chondroblasts, may also produce these substances. Mechanical character ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breast Cancer
Breast cancer is a cancer that develops from breast tissue. Signs of breast cancer may include a Breast lump, lump in the breast, a change in breast shape, dimpling of the skin, Milk-rejection sign, milk rejection, fluid coming from the nipple, a newly inverted nipple, or a red or scaly patch of skin. In those with Metastatic breast cancer, distant spread of the disease, there may be bone pain, swollen lymph nodes, shortness of breath, or yellow skin. Risk factors for developing breast cancer include obesity, a Sedentary lifestyle, lack of physical exercise, alcohol consumption, hormone replacement therapy during menopause, ionizing radiation, an early age at Menarche, first menstruation, having children late in life (or not at all), older age, having a prior history of breast cancer, and a family history of breast cancer. About five to ten percent of cases are the result of an inherited genetic predisposition, including BRCA mutation, ''BRCA'' mutations among others. Breast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiography
Radiography is an imaging technology, imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical ("diagnostic" radiography and "therapeutic radiography") and industrial radiography. Similar techniques are used in airport security, (where "body scanners" generally use backscatter X-ray). To create an image in conventional radiography, a beam of X-rays is produced by an X-ray generator and it is projected towards the object. A certain amount of the X-rays or other radiation are absorbed by the object, dependent on the object's density and structural composition. The X-rays that pass through the object are captured behind the object by a X-ray detector, detector (either photographic film or a digital detector). The generation of flat two-dimensional images by this technique is called Projection radiography, projectional radiography. In computed tomography (C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
