See ROI.

A user-defined area of the spectrum which contains data of particular interest, such as a peak.

User-defined, rectangular exposure area on the CCD.

the area of anatomy being scanned that is of particular importance in the image.

Target area.

An area of the patient's anatomy encompassing the target (tumor) and/or any surrounding sensitive structures (Regions at Risk, or RARs).

In imaging terms, this is the portion of the image in which the processing is applied.

Localised part of an image defined by the operator which is of particular interest at a given time.