Functional imaging (or physiological imaging) is a
medical imaging technique of detecting or measuring changes in
metabolism
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run c ...
, blood flow, regional chemical composition, and absorption.
As opposed to structural imaging, functional imaging centers on revealing
physiological activities within a certain tissue or organ by employing medical image modalities that very often use
tracers or probes to reflect spatial distribution of them within the body. These tracers are often
analogous
Analogy (from Greek ''analogia'', "proportion", from ''ana-'' "upon, according to" lso "against", "anew"+ ''logos'' "ratio" lso "word, speech, reckoning" is a cognitive process of transferring information or meaning from a particular subject ...
to some chemical compounds, like glucose, within the body. To achieve this, isotopes are used because they have similar chemical and biological characteristics. By appropriate proportionality, the
nuclear medicine physician
Nuclear medicine physicians, also called nuclear radiologists or simply nucleologists, are medical specialists that use tracers, usually radiopharmaceuticals, for diagnosis and therapy. Nuclear medicine procedures are the major clinical applicati ...
s can determine the real intensity of certain substance within the body to evaluate the risk or danger of developing some diseases.
Modalities
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Positron emission tomography (PET)
**
Fludeoxyglucose
18F.html" ;"title="sup>18F">sup>18Fluorodeoxyglucose ( INN), or fluorodeoxyglucose F 18 (USAN and USP), also commonly called fluorodeoxyglucose and abbreviated 18F.html" ;"title="sup>18F">sup>18FDG, 2- 18F.html" ;"title="sup>18F">sup>18FDG or ...
for Glucose metabolism
** O-15 as a flow tracer
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Single-photon emission computed tomography (SPECT)
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Computed tomography (CT) perfusion imaging
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Functional magnetic resonance imaging (fMRI)
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BOLD
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Diffusion MRI
Diffusion-weighted magnetic resonance imaging (DWI or DW-MRI) is the use of specific MRI sequences as well as software that generates images from the resulting data that uses the diffusion of water molecules to generate contrast in MR images. It ...
**
Perfusion (blood flow)
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Arterial spin labeling MRI
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Blood volume
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Hyperpolarized carbon-13 MRI
Hyperpolarized carbon-13 MRI is a functional medical imaging technique for probing perfusion and metabolism using injected substrates.
It is enabled by techniques for hyperpolarization of carbon-13-containing molecules using dynamic nuclear po ...
*
Functional photoacoustic microscopy (fPAM)
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Magnetic particle imaging Magnetic particle imaging (MPI) is an emerging non-invasive tomographic technique that directly detects superparamagnetic nanoparticle tracers. The technology has potential applications in diagnostic imaging and material science. Currently, it i ...
(MPI)
*
Optical imaging Medical optical imaging is the use of light as an investigational imaging technique for medical applications. Examples include optical microscopy, spectroscopy, endoscopy, scanning laser ophthalmoscopy, laser Doppler imaging, and optical coherence ...
**
Near-infrared spectroscopy
Near-infrared spectroscopy (NIRS) is a spectroscopic method that uses the near-infrared region of the electromagnetic spectrum (from 780 nm to 2500 nm). Typical applications include medical and physiological diagnostics and research inc ...
(NIRS)
See also
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Biomedical engineering
Biomedical engineering (BME) or medical engineering is the application of engineering principles and design concepts to medicine and biology for healthcare purposes (e.g., diagnostic or therapeutic). BME is also traditionally logical sciences ...
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Medical imaging
*
PET-CT
Positron emission tomography–computed tomography (better known as PET-CT or PET/CT) is a nuclear medicine technique which combines, in a single gantry, a positron emission tomography (PET) scanner and an x-ray computed tomography (CT) scan ...
*
Radiology
Radiology ( ) is the medical discipline that uses medical imaging to diagnose diseases and guide their treatment, within the bodies of humans and other animals. It began with radiography (which is why its name has a root referring to radiat ...
*
Functional neuroimaging
Functional neuroimaging is the use of neuroimaging technology to measure an aspect of brain function, often with a view to understanding the relationship between activity in certain brain areas and specific mental functions. It is primarily used a ...
References
{{Reflist
External links
Scholarpedia Functional imaging Medical imaging