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 ...
, blood flow, regional chemical composition, and absorption.
As opposed to structural imaging, functional imaging centers on revealing
physiological
Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemica ...
activities within a certain tissue or organ by employing medical image modalities that very often use
tracers
Tracer may refer to:
Science
* Flow tracer, any fluid property used to track fluid motion
* Fluorescent tracer, a substance such as 2-NBDG containing a fluorophore that is used for tracking purposes
* Histochemical tracer, a substance used for ...
or probes to reflect spatial distribution of them within the body. These tracers are often
analogous 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 physicians can determine the real intensity of certain substance within the body to evaluate the risk or danger of developing some diseases.
Modalities
*
Positron emission tomography (PET)
**
Fludeoxyglucose for Glucose metabolism
** O-15 as a flow tracer
*
Single-photon emission computed tomography (SPECT)
*
Computed tomography (CT) perfusion imaging
*
Functional magnetic resonance imaging
Functional magnetic resonance imaging or functional MRI (fMRI) measures brain activity by detecting changes associated with blood flow. This technique relies on the fact that cerebral blood flow and neuronal activation are coupled. When an area o ...
(fMRI)
**
BOLD
**
Diffusion MRI
**
Perfusion (blood flow)
**
Arterial spin labeling MRI
**
Blood volume
**
Hyperpolarized carbon-13 MRI
*
Functional photoacoustic microscopy (fPAM)
*
Magnetic particle imaging (MPI)
*
Optical imaging
**
Near-infrared spectroscopy (NIRS)
See also
*
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 ...
*
Medical imaging
*
PET-CT
*
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
References
{{Reflist
External links
Scholarpedia Functional imaging Medical imaging