Medical imaging seeks to reveal internal structures hidden by the skin and bones, as well as to diagnose and treat disease.

[citation needed] Measurement and recording techniques that are not primarily designed to produce images, such as electroencephalography (EEG), magnetoencephalography (MEG), electrocardiography (ECG), and others, represent other technologies that produce data susceptible to representation as a parameter graph versus time or maps that contain data about the measurement locations.

When the RF pulse is turned off, the protons "relax" back to alignment with the primary magnet and emit radio-waves in the process.

Modern MRI instruments are capable of producing images in the form of 3D blocks, which may be considered a generalization of the single-slice, tomographic, concept.

However, there are well-identified health risks associated with tissue heating from exposure to the RF field and the presence of implanted devices in the body, such as pacemakers.

In MRI, while any nucleus with a net nuclear spin can be used, the proton of the hydrogen atom remains the most widely used, especially in the clinical setting, because it is so ubiquitous and returns a large signal.

Images are acquired after collimated photons are detected by a crystal that gives off a light signal, which is in turn amplified and converted into count data.

Medical ultrasound uses high frequency broadband sound waves in the megahertz range that are reflected by tissue to varying degrees to produce (up to 3D) images.

While it may provide less anatomical detail than techniques such as CT or MRI, it has several advantages which make it ideal in numerous situations, in particular that it studies the function of moving structures in real-time, emits no ionizing radiation, and contains speckle that can be used in elastography.

The concepts of ultrasound differ from other medical imaging modalities in the fact that it is operated by the transmission and receipt of sound waves.

[16] In the last decade, a steady increase of activities in the field of elastography is observed demonstrating successful application of the technology in various areas of medical diagnostics and treatment monitoring.

Echocardiography is widely used in an array of patients ranging from those experiencing symptoms, such as shortness of breath or chest pain, to those undergoing cancer treatments.

Transthoracic ultrasound has been proven to be safe for patients of all ages, from infants to the elderly, without risk of harmful side effects or radiation, differentiating it from other imaging modalities.

In emergency situations, echocardiography is quick, easily accessible, and able to be performed at the bedside, making it the modality of choice for many physicians.

[20] Projectional radiography, CT scan and nuclear medicine imaging result some degree of ionizing radiation exposure, but have with a few exceptions much lower absorbed doses than what are associated with fetal harm.

Some of the data that radiologists discard could save patients time and money, while reducing their exposure to radiation and risk of complications from invasive procedures.

[22][23] Volume rendering techniques have been developed to enable CT, MRI and ultrasound scanning software to produce 3D images for the physician.

It was a key resource for the famous, but ultimately unsuccessful attempt by Singaporean surgeons to separate Iranian twins Ladan and Laleh Bijani in 2003.

Neuroimaging has also been used in experimental circumstances to allow people (especially disabled persons) to control outside devices, acting as a brain computer interface.

In most scenarios, a frame grabber is used in order to capture the video signal from the medical device and relay it to a computer for further processing and operations.

"[32] Medical imaging has become a major tool in clinical trials since it enables rapid diagnosis with visualization and quantitative assessment.

Trials that rely solely on clinical endpoints are very costly as they have long durations and tend to need large numbers of patients.

[40] An imaging-based trial will usually be made up of three components: Medical imaging can lead to patient and healthcare provider harm through exposure to ionizing radiation, iodinated contrast, magnetic fields, and other hazards.

[43] While there has not been any definitive legal decision in the matter, at least one study has indicated that medical imaging may contain biometric information that can uniquely identify a person, and so may qualify as PHI.

As such, one should be particularly careful about the anonymity of a recordings of an X-ray image before using or publishing them without consent in journals and other learning materials, whether they are printed or in an electronic format.

[47][48] Notable manufacturers as of 2012 included Fujifilm,GE HealthCare, Siemens Healthineers, Philips, Shimadzu, Toshiba, Carestream Health, Hitachi, Hologic, and Esaote.

Copyright Office Practices, "the Office will not register works produced by a machine or mere mechanical process that operates randomly or automatically without any creative input or intervention from a human author" including "Medical imaging produced by X-rays, ultrasounds, magnetic resonance imaging, or other diagnostic equipment.

The literature seems to uniformly consider the medical doctor, dentist or veterinary physician as the rights holder, which may result from the circumstance that in Germany many X-rays are performed in ambulatory settings.

Medical images created in the United Kingdom will normally be protected by copyright due to "the high level of skill, labour and judgement required to produce a good quality X-ray, particularly to show contrast between bones and various soft tissues".

Physicians employed at the hospital will, in their contracts, be given the right to publish patient information in journal papers or books they write (providing they are made anonymous).