Inferior Frontal Sulcus

INFERIOR FRONTAL SULCUS

The Inferior Frontal Sulcus (IFS) separates the middle frontal from the inferior frontal gyrus. It is also a sulcus running posterior to anterior, in the lower dorsolateral sector of the hemisphere. It also starts at the preCS with which it can merge. It ends anteriorly, most often with a downturn towards the orbital surface of the frontal lobe (1). This downturn, however, is very variable and on occasion, the IFS does not have an anterior downturn and ends as a straight line in the continuation of the main sector (2). It actually terminates in the direction of the Lateral Orbital Sulcus (see below).

Drop the first point of the curve at the posterior end, immediately in front of the preCS, even if the IFS reaches the preCS or crosses it (3). Then proceed to the end of the straight segment (4) and end the tracing there even if the sulcus curves down. We do this for consistency in alignment.

USC Biomedical Imaging Research Lab © 2009, designed by Dimitrios Pantazis