The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. The positron has an electric charge of +1 e, a spin of 1/2, and has the same mass as an electron. When a positron collides with an electron, annihilation occurs. If this collision occurs at low energies, it results in the production of two or more gamma ray photons.
Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, and also has similarities to arsenic. It rarely occurs in its elemental state or as pure ore compounds in the Earth's crust. Selenium was discovered in 1817 by Jöns Jacob Berzelius, who noted the similarity of the new element to the previously discovered tellurium.
X-rays make up X-radiation, a form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz (3×1016 Hz to 3×1019 Hz) and energies in the range 100 eV to 100 keV. X-ray wavelengths are shorter than those of UV rays and typically longer than those of gamma rays. In many languages, X-radiation is referred to as Röntgen radiation, after the German scientist Wilhelm Röntgen who discovered it on November 8, 1895. He named it X-radiation to signify an unknown type of radiation. Spelling of X-ray(s) in the English language includes the variants x-ray(s), xray(s), and X ray(s).
A beta particle, also called beta ray or beta radiation, is a high-energy, high-speed electron or positron emitted by the radioactive decay of an atomic nucleus during the process of beta decay. There are two forms of beta decay, β− decay and β+ decay, which produce electrons and positrons respectively.
Mammography is the process of using low-energy X-rays to examine the human breast for diagnosis and screening. The goal of mammography is the early detection of breast cancer, typically through detection of characteristic masses or microcalcifications.
Digital radiography is a form of radiography that uses x-ray–sensitive plates to directly capture data during the patient examination, immediately transferring it to a computer system without the use of an intermediate cassette. Advantages include time efficiency through bypassing chemical processing and the ability to digitally transfer and enhance images. Also, less radiation can be used to produce an image of similar contrast to conventional radiography.
Xeromammography is a photoelectric method of recording an x-ray image on a coated metal plate, using low-energy photon beams, long exposure time, and dry chemical developers.
A fold of peritoneum, the phrenicocolic ligament is continued from the left colic flexure to the thoracic diaphragm opposite the tenth and eleventh ribs; it passes below and serves to support the spleen, and therefore has received the name of sustentaculum lienis.
Breast cancer screening is the medical screening of asymptomatic, apparently healthy women for breast cancer in an attempt to achieve an earlier diagnosis. The assumption is that early detection will improve outcomes. A number of screening tests have been employed, including clinical and self breast exams, mammography, genetic screening, ultrasound, and magnetic resonance imaging.
In oncology, a spiculated mass is a lump of tissue with spikes or points on the surface. It is suggestive but not diagnostic of malignancy, i.e. cancer. It's a common mammography finding in carcinoma breast.
Stereotactic biopsy, also known as stereotactic core biopsy, is a biopsy procedure that uses a computer and imaging performed in at least two planes to localize a target lesion in three-dimensional space and guide the removal of tissue for examination by a pathologist under a microscope. Stereotactic core biopsy makes use of the underlying principle of parallax to determine the depth or "Z-dimension" of the target lesion.
A Mammotome device is a vacuum assisted breast biopsy device that uses image guidance such as x-ray, ultrasound and/or MRI to perform breast biopsies. A biopsy using a Mammotome device can be done on an outpatient basis with a local anesthetic. Mammotome is a registered trademark of Devicor Medical Products, Inc., part of Leica Biosystems.
A double-contrast barium enema is a form of contrast radiography in which x-rays of the colon and rectum are taken using two forms of contrast to make the structures easier to see. A liquid containing barium is put into the rectum. Barium is a silver-white metallic compound that outlines the colon and rectum on an x-ray and helps show abnormalities. Air is also put into the rectum and colon to further enhance the x-ray.
Scintimammography is a type of breast imaging test that is used to detect cancer cells in the breasts of some women who have had abnormal mammograms, or for those who have dense breast tissue, post-operative scar tissue or breast implants.
Fatty-replaced breast tissue is a term used in mammography that refers to the replacement of breast tissue with fatty tissue. This commonly occurs as a woman ages.
Flat panel detectors are a class of solid-state x-ray digital radiography devices similar in principle to the image sensors used in digital photography and video. They are used in both projectional radiography and as an alternative to x-ray image intensifiers (IIs) in fluoroscopy equipment.
Positron emission mammography (PEM) is a nuclear medicine imaging modality used to detect or characterise breast cancer. Mammography typically refers to x-ray imaging of the breast, while PEM uses an injected positron emitting isotope and a dedicated scanner to locate breast tumors. Scintimammography is another nuclear medicine breast imaging technique, however it is performed using a gamma camera. Breasts can be imaged on standard whole-body PET scanners, however dedicated PEM scanners offer advantages including improved resolution.
X-ray detectors are devices used to measure the flux, spatial distribution, spectrum, and/or other properties of X-rays.
Dynamic angiothermography (DATG) is a technique for the diagnosis of breast cancer. This technique, though springing from the thermography of old conception, is based on a completely different principle. DATG records the temperature variations linked to the vascular changes in the breast due to angiogenesis. The presence, change, and growth of tumors and lesions in breast tissue change the vascular network in the breast. Consequently, measuring the vascular structure over time, DATG effectively monitors the change in breast tissue due to tumors and lesions. It is currently used in combination with other techniques for diagnosis of breast cancer. This diagnostic method is a low cost one compared with other techniques.
In medicine, breast imaging is the representation or reproduction of a breast's form. There are various methods of breast imaging.
