Medical imaging

Medical imaging refers to the techniques and processes used to create images of the human body (or parts thereof) for clinical purposes (medical procedures seeking to reveal, diagnose or examine disease) or medical science (including the study of normal anatomy and physiology).

As a discipline and in its widest sense, it is part of biological imaging and incorporates radiology (in the wider sense), radiological sciences, endoscopy, (medical) thermography, medical photography and microscopy (e.g. for human pathological investigations).

Measurement and recording techniques which are not primarily designed to produce images, such as electroencephalography (EEG) and magnetoencephalography (MEG) and others, but which produce data susceptible to be represented as maps (i.e. containing positional information), can be seen as forms of medical imaging.

In the clinical context, medical imaging is generally equated to radiology or "clinical imaging" and the medical practitioner responsible for interpreting (and sometimes acquiring) the images is a radiologist. Diagnostic radiography designates the technical aspects of medical imaging and in particular the acquisition of medical images. The radiographer or radiologic technologist is usually responsible for acquiring medical images of diagnostic quality, although some radiological interventions are performed by radiologists.

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 (e.g. radiography), modelling 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 (neuroscience, cardiology, psychiatry, psychology, etc) under investigation. Many of the techniques developed for medical imaging also have scientific and industrial applications.

Medical imaging is often perceived to designate of the set of techniques that noninvasively produce images of the internal aspect of the body. In this restricted sense, medical imaging can be seen as the solution of mathematical inverse problems. This means that cause (the properties of living tissue) is inferred from effect (the observed signal). In the case of ultrasonography the probe consists of ultrasonic pressure waves and echoes inside the tissue show the internal structure. In the case of projection radiography, the probe is X-ray radiation which is absorbed at different rates in different tissue types such as bone, muscle and fat.
from : http://en.wikipedia.org/wiki/Diagnostic_radiology

Areas of specialty

Medical imaging
* Diagnostic radiology, including x-rays, fluoroscopy, mammography, Dual energy X-ray absorptiometry, angiography and Computed tomography
* Ultrasound, including intravascular ultrasound
* Non-ionising radiation (Lasers, Ultraviolet etc.)
* Nuclear medicine, including SPECT and positron emission tomography (PET)
* Magnetic resonance imaging (MRI), including functional magnetic resonance imaging (fMRI) and other methods for functional neuroimaging of the brain.
o For example, nuclear magnetic resonance (often referred to as magnetic resonance imaging to avoid the common concerns about radiation), uses the phenomenon of nuclear resonance to image the human body.
* Magnetoencephalography
* Electrical impedance tomography
* Diffuse optical imaging
* Optical coherence tomography


Treatment of disease

* Defibrillation
* High intensity focussed ultrasound, including lithotripsy
* Interventional radiology
* Non-ionising radiation Lasers, Ultraviolet etc. including photodynamic therapy and Lasik
* Nuclear medicine, including unsealed source radiotherapy
* Photomedicine, the use of light to treat and diagnose disease
* Radiotherapy
o TomoTherapy
o Cyberknife
o Gamma knife
o Proton therapy
o Brachytherapy
o Boron Neutron Capture Therapy
* Sealed source radiotherapy
* Terahertz radiation


Physiological measurement techniques

Used to monitor and measure various physiological parameters. Many physiological measurement techniques are non-invasive and can be used in conjunction with, or as an alternative to, other invasive methods.

* Electrocardiography
* Electromyography
* Electroencephalography
* Electronystagmography
* Endoscopy
* Medical ultrasonography
* Non-ionising radiation (Lasers, Ultraviolet etc.)
* Near infrared spectroscopy
* Pulse oximetry
* Blood gas monitor
* Blood pressure measurement


Radiation protection

* Background radiation
* Radiation protection
* Dosimetry
* Health Physics
* Radiological Protection of Patients


Medical computing and mathematics

* Medical informatics
* Telemedicine
* Picture archiving and communication systems (PACS)
* DICOM
* Tomographic reconstruction, an ill-posed inverse problem
* Advanced Digital Imaging Solutions Laboratory[ADISL]