Definition - What does Region of Interest (ROI) mean?
A region of interest (ROI) is a subset of an image or a dataset identified for a particular purpose. The dataset could be any of the following:
Waveform or 1D dataset: The ROI is a time or frequency interval on the waveform (a graph of some quantity plotted against time).
Image or 2D dataset: The ROI is defined by given boundaries on an image of an object or on a drawing.
Volume or 3D dataset: The ROI is the contours or the surfaces defining a physical object.
Time-Volume or 4D dataset: Concerning the changing 3D dataset of an object changing in shape with time, the ROI is the 3D dataset during a specific time or period of time.
ROI is most commonly used for medical imaging, e.g. as a particular portion of a 2D, 3D or 4D image that is of concern during a diagnosis or of interest during research. When the movement of an organ has an ROI, how the object moves during a specific time or period of time may be the ROI for either a doctor’s diagnosis or a researcher’s study.