Region of Interest | ROI

A Region of Interest (ROI) refers to a specific area or volume within a medical imaging examination that is selectively chosen for detailed analysis. This ROI can be manually designated by the user or automatically identified through specific algorithms. A histogram, i.e., graph showing the distribution of pixel values and frequency within the ROI can be shown from which various measurements can be derived, such as the maximum, minimum, mean, and standard deviation of particular properties, such as Hounsfield Units, signal intensity, FDG avidity, etc., depending on the imaging modality used. These measurements offer valuable insights into the properties of the structures encompassed within the ROI. For instance, they can be used to analyze the characteristics of a tumor or other anatomical structures.