Medical imaging

Medical imaging is the technique and process used to produce images of the human body or its internal aspects for medical or clinical purposes. This may include the medical study of normal anatomy and physiology or medical procedures seeking to reveal, diagnose, or examine disease. Though the process is often thought of as being non-invasive from the standpoint medical imaging modalities do not penetrate the skin physically, on the electromagnetic and radiation level, they are quite invasive. From the high energy photons in x-ray computed tomography to the Tesla coils of an MRI device, these modalities alter the physical and chemical environment of the body in order to obtain data.^[1] In 2006, radiation exposure from computed tomography (CT) and nuclear medicine contributed 36 percent of the total radiation exposure in the United States.^[2]

In 2010 an estimated five billion medical imaging studies had been conducted worldwide.^[3] Consulting company Pell Research found as of October 2012 the majority of diagnostic imaging centers in the United States are located in California, followed by Texas and Florida.^[4]

What constitutes medical imaging

In its widest sense, this discipline is considered part of biological imaging and incorporates radiology, nuclear medicine, investigative radiological sciences, endoscopy, medical thermography, and medical photography.^[1]

In the clinical context, "invisible light" medical imaging is generally equated to radiology or "clinical imaging," and the medical practitioner responsible for interpreting and/or acquiring the images is a radiologist. "Visible light" medical imaging involves digital video or still pictures that can be seen without special equipment.^[1] Dermatology and wound care are two modalities that utilize visible light imagery. Diagnostic radiography designates the technical aspects of medical imaging and in particular the acquisition of medical images.^[1] The radiographer or radiologic technologist is usually responsible for acquiring medical images of diagnostic quality, although some radiological interventions are performed by radiologists. Note while radiology is an evaluation of anatomy, nuclear medicine provides functional assessment.

As a field of scientific investigation, medical imaging constitutes a sub-discipline of biomedical engineering, medical physics, or medicine, depending on the context. Research and development in the area of instrumentation, image acquisition, modeling, and quantification are usually the preserve of biomedical engineering, medical physics, and computer science; research into the application and interpretation of medical images is usually the preserve of radiology and the medical sub-discipline relevant to medical condition or area of medical science under investigation.

Measurement and recording techniques which are not primarily designed to produce images such as electroencephalography (EEG), magnetoencephalography (MEG), and electrocardiography (EKG), but which produce data susceptible to be represented as maps (i.e., containing positional information), can be seen as forms of medical imaging. Note, however, that while imaging of removed organs and tissues can be performed for medical reasons, such procedures are typically not referred to as medical imaging, but rather as pathological study.