Spillover effect can be defined as an apparent gain in activity for small objects or regions, as opposed to the
partial volume effect. It occurs often in
biological imaging Biological imaging may refer to any imaging technique used in biology.
Typical examples include:
* Bioluminescence imaging, a technique for studying laboratory animals using luminescent protein
* Calcium imaging, determining the calcium status of a ...
modalities such as
positron emission tomography
Positron emission tomography (PET) is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in Metabolism, metabolic processes, and in other physiological activities including bl ...
(PET) and
single-photon emission computed tomography
Single-photon emission computed tomography (SPECT, or less commonly, SPET) is a nuclear medicine tomographic imaging technique using gamma rays. It is very similar to conventional nuclear medicine planar imaging using a gamma camera (that is, ...
(SPECT) because of their limited spatial resolution. Although partial volume effect and spillover refer to essentially the same physical problem, it is important to distinguish the outcome of these two different effects. For
partial volume effect, the apparent loss of activity in the object is distributed across adjacent
voxels
In 3D computer graphics, a voxel represents a value on a regular grid in three-dimensional space. As with pixels in a 2D bitmap, voxels themselves do not typically have their position (i.e. coordinates) explicitly encoded with their values. Ins ...
, which are considered outside the object, resulting in increase in activity in these voxels. This increase in activity is referred to as spillover, whereas loss in activity is referred to as partial volume loss.
See also
*
Partial volume (imaging) The partial volume effect can be defined as the loss of apparent activity in small objects or regions because of the limited resolution of the imaging system. It occurs in medical imaging and more generally in biological imaging such as positron ...
References
Cardiac imaging
Neuroimaging
{{med-imaging-stub