Radiography is an imaging technique using X-rays, gamma rays, or similar radiation to view the internal form of an object. To create the image, a beam of X-rays or other form of electromagnetic radiation is produced by an X-ray generator and is projected toward the object. A certain amount of the X-rays or other radiation is 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 detector. The generation of flat two dimensional images by this technique is called projectional radiography. In computed tomography an X-ray source and its associated detectors rotate around the subject which itself moves through the conical X-ray beam produced. Any given point within the subject is crossed from many directions by many different beams at different times. Information regarding attenuation of these beams is collated and subjected to computation to generate two dimensional images in three planes which can be further processed to produce a three dimensional image.
Radiology is the medical specialty that uses medical imaging to diagnose and treat diseases within the human body.
Medical physics is, in general, the application of physics concepts, theories, and methods to medicine or healthcare. Medical physics departments may be found in hospitals or universities.
Medical imaging is the technique and process of creating visual representations of the interior of a body for clinical analysis and medical intervention, as well as visual representation of the function of some organs or tissues (physiology). Medical imaging seeks to reveal internal structures hidden by the skin and bones, as well as to diagnose and treat disease. Medical imaging also establishes a database of normal anatomy and physiology to make it possible to identify abnormalities. Although imaging of removed organs and tissues can be performed for medical reasons, such procedures are usually considered part of pathology instead of medical imaging.
Radiation protection, also known as radiological protection, is defined by the International Atomic Energy Agency (IAEA) as "The protection of people from harmful effects of exposure to ionizing radiation, and the means for achieving this". The IAEA also states "The accepted understanding of the term radiation protection is restricted to protection of people. Suggestions to extend the definition to include the protection of non-human species or the protection of the environment are controversial". Exposure can be from a radiation source external to the human body or due to the bodily intake of a radioactive material.
A coronary catheterization is a minimally invasive procedure to access the coronary circulation and blood filled chambers of the heart using a catheter. It is performed for both diagnostic and interventional (treatment) purposes.
Radiocontrast agents are substances used to enhance the visibility of internal structures in X-ray-based imaging techniques such as computed tomography, projectional radiography, and fluoroscopy. Radiocontrast agents are typically iodine, barium-sulphate or gadolinium based compounds. They absorb external X-rays, resulting in decreased exposure on the X-ray detector. This is different from radiopharmaceuticals used in nuclear medicine which emit radiation.
An x-ray image intensifier (XRII) is an image intensifier that converts x-rays into visible light at higher intensity than the more traditional fluorescent screens can. Such intensifiers are used in x-ray imaging systems to allow low-intensity x-rays to be converted to a conveniently bright visible light output. The device contains a low absorbency/scatter input window, typically aluminum, input fluorescent screen, photocathode, electron optics, output fluorescent screen and output window. These parts are all mounted in a high vacuum environment within glass or more recently, metal/ceramic. By its intensifying effect, It allows the viewer to more easily see the structure of the object being imaged than fluorescent screens alone, whose images are dim. The XRII requires lower absorbed doses due to more efficient conversion of x-ray quanta to visible light. This device was originally introduced in 1948.
A radiation burn is damage to the skin or other biological tissue as an effect of radiation. The radiation types of greatest concern are thermal radiation, radio frequency energy, ultraviolet light and ionizing radiation.
Radiographers, also known as radiologic technologists, diagnostic radiographers and medical radiation technologists are healthcare professionals who specialise in the imaging of human anatomy for the diagnosis and treatment of pathology. Radiographers are infrequently, and almost always erroneously, known as x-ray technicians. In countries that use the title radiologic technologist they are often informally referred to as techs in the clinical environment; this phrase has emerged in popular culture such as television programmes. The term radiographer can also refer to a therapeutic radiographer, also known as a radiation therapist.
Industrial radiography is a method of non-destructive testing where many types of manufactured components can be examined to verify the internal structure and integrity of the specimen. Industrial Radiography can be performed utilizing either X-rays or gamma rays. Both are forms of electromagnetic radiation. The difference between various forms of electromagnetic energy is related to the wavelength. X and gamma rays have the shortest wavelength and this property leads to the ability to penetrate, travel through, and exit various materials such as carbon steel and other metals.
Dental radiographs are commonly called X-rays. Dentists use radiographs for many reasons: to find hidden dental structures, malignant or benign masses, bone loss, and cavities.
CT pulmonary angiogram (CTPA) is a medical diagnostic test that employs computed tomography (CT) angiography to obtain an image of the pulmonary arteries. Its main use is to diagnose pulmonary embolism (PE). It is a preferred choice of imaging in the diagnosis of PE due to its minimally invasive nature for the patient, whose only requirement for the scan is an intravenous line.
Patients are exposed to ionizing radiations when they undergo diagnostic examinations using x-rays or radiopharmaceuticals, therapy of cancer or benign lesions using radiations emitted by radioisotopes or those by radiation generators; and in interventional procedures using fluoroscopy. There has been a tremendous increase in the use of ionizing radiation in medicine during recent decades. Health professionals and patients are concerned about the harmful effects of radiation. International Atomic Energy Agency (IAEA) has established a programme on radiological protection of patients in recognition of the increasing importance of this topic. The emphasis in the past had been on radiation protection of staff and this emphasis has helped to reduce radiation doses to staff to levels much below the dose limits prescribed by the International Commission on Radiological Protection (ICRP) and accepted by most countries. The recent emphasis on radiation protection of patients is helping in developing strategies to reduce radiation doses to patient without compromising on diagnostic or therapeutic purpose.
A panoramic radiograph is a panoramic scanning dental X-ray of the upper and lower jaw. It shows a two-dimensional view of a half-circle from ear to ear. Panoramic radiography is a form of focal plane tomography; thus, images of multiple planes are taken to make up the composite panoramic image, where the maxilla and mandible are in the focal trough and the structures that are superficial and deep to the trough are blurred.
Paediatric radiology is a subspecialty of radiology involving the imaging of fetuses, infants, children, adolescents, and young adults. Many paediatric radiologists practice at children's hospitals.
Cone beam computed tomography is a medical imaging technique consisting of X-ray computed tomography where the X-rays are divergent, forming a cone.
A hybrid operating room is a surgical theatre that is equipped with advanced medical imaging devices such as fixed C-Arms, CT scanners or MRI scanners. These imaging devices enable minimally-invasive surgery. Minimally-invasive surgery is intended to be less traumatic for the patient and minimize incisions on the patient and perform surgery procedure through one or several small cuts.
