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region of interest (ROI)

an area on a digital image that circumscribes a desired anatomical location. Image processing systems permit drawing of ROIs on images. The average parametric value is computed for all pixels within the ROI and returned to the operator.


Abbreviation for:
range of interest
reactive oxygen intermediate
return on investment


(re'jon) [L. regio, boundary]
A portion of the body with natural or arbitrary boundaries. Synonym: regioregional (-al), adjective
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abdominal regions

The abdomen and its external surface, divided into nine regions by four imaginary planes: two horizontal, one at the level of the ninth costal cartilage (or the lowest point of the costal arch) and the other at the level of the highest point of the iliac crest; two vertical, through the centers of the inguinal ligaments (or through the nipples or through the centers of the clavicles) or curved and coinciding with the lateral borders of the two abdominal rectus muscles.
See: illustration

chest region

Any of the three areas of the chest: anterior, posterior, and lateral. The anterior divisions (right and left) are the clavicular, infraclavicular, and supraclavicular, the mammary and inframammary, and the upper and lower sternal. The posterior divisions (right and left) are the scapular, infrascapular, interscapular, and suprascapular. The lateral divisions are the axillary and infra-axillary.

hypochondriac region


hypogastric region


iliac region

The inguinal region on either side of the hypogastrium.

inguinal region


lumbar region

That area of the abdominal surface lateral to the umbilical region, above the iliac region, and below the hypochondriac region.

region of interest

Abbreviation: ROI
In radiology, the object of a study or a treatment designed to affect a limited part of the body.

parasternal region

The area between the sternal border and parasternal line.

sternomastoid region

The wide area on the lateral region of the neck covered by sternocleidomastoid muscle.

region of interest

Abbreviation: ROI
In radiology, the object of a study or a treatment designed to affect a limited part of the body.
See also: region
References in periodicals archive ?
Second, if arbitrary ROI sharps are desired, the shape coding will consume a large number of bits, which significantly decreases the overall coding efficiency.
An asynchronous replication solution can be used for DR, but it can also be used for other things that affect ROI.
ROI benefit: The reduction of time and effort for users to access the necessary information to do their job leads to an increase in accuracy and reduction of costly errors caused by missing or limited information.
A word of caution: as with any serious initiative, this information is useless unless someone has direct, overall responsibility for tracking training's ROI.
Similarly, those professional communicators who are quick to adapt to the changing PR environment by meeting the ROI challenge will prosper.
The depth of the ROI should be to prove "how quickly" the payback is, not to determine if the payback will occur.