Medical imaging data typically involves medical photography that catalogs the anatomy and physiology of different body areas, usually for diagnostic purposes. This data may come from non-invasive visible light picture-taking or from invisible light techniques that occur inside the body. Input may be compiled using a variety of techniques, such as radiation, body temperature, and sound waves. Resulting data compiled from these technique include X-rays, magnetic resonance imaging (MRI) scans, ultrasounds, thermographs, and tomography scans.
Two main methods are used to generate medical imaging data: invisible light and visible light technology. The latter variety produces more traditional medical photography images via still photographs or digital video. Pictures of outer skin wounds are one example of visible light techniques. Invisible light, on the other hand, usually requires special equipment to produce endoscopic images from inside the body.
One of the primary means of medical imaging is through radiation absorption by body tissues. Traditional radiology technique produces X-ray films, or projection radiographs, that are readouts of electromagnetic radiation. X-ray technology allows development of inner bodily images that can detect abnormalities in a given area, particularly in the skeletal system. When lower amounts of radiation are pulsed more frequently through the body, the physician can use an image receptor to create fluoroscopic images of inner body regions. These real-time images are typically conveyed on a digital screen.
Nuclear medicine has produced its own set of medical imaging data. For one, a magnetic resonance imaging (MRI) scanner can magnetize the interior of water cells in tissue, which creates a signal. This signal is then converted into a digital image via an MRI scan readout. Other forms of nuclear imaging that can produce two-dimensional or three-dimensional images are known as single-photon emission computed tomography (SPECT) and positron emission tomography (PET). These data images result from the injection of radioisotopes into the body.
SPECT and PET scans are forms of tomography, since images are gathered in sections via the reading of wave signals. Other data that may result from tomography are computed tomography (CT) scans and computed axial tomography (CAT) scans. These methods often involve placing a patient in a tube where x-rays are taken from several directions. Tomography methods are useful for hard-to-access areas of the body.
Another medical imaging method uses sound waves to create pictures. When body tissues reflect these sound waves, three-dimensional images can be created and seen. The data yielded by these imaging techniques can be produced as an ultrasound that is viewable on a screen or as a still image. Fetal and abdominal regions are common areas in which ultrasonography is used.
Body heat can also be useful in creating medical imaging data. Thermograms result when infrared cameras trace body temperature changes on the surface of the skin. A wide range of potential disorders ranging from metabolic abnormalities to breast cancer have been detected via thermography data-yielding techniques.
In addition, some forms of medical imaging data are not actual images, but rather consist of maps that catalog bodily functions. Electroencephalography (EEG) and electrocardiography (EKG) are two such examples. These visual outputs show charts of brain wave activity and heart rate, respectively.