Calcarine Sulcus

The Calcarine Sulcus (CalcS) is a deep antero-posterior sulcus which starts in the temporal lobe, under the splenium of the corpus callosum, and continues in the direction of the occipital pole. The CalcS splits the mesial occipital lobe into two sectors, the superior or cuneus, and the inferior or infra-calcarine sector, a combination of lingual and fusiform gyri. The banks of the CalcS contain the primary visual cortex.

The CalcS should be traced from anterior (1) to posterior (2). The course is quite variable from subject to subject, but the main direction is always the same. It may end at the pole, on the mesial surface of the hemisphere, or even course to the lateral surface of the hemisphere, in a straight line, or curve downward (3), or split into a T (4). For the purpose of aligning brains, the lower split should be chosen (5).

Both these types of termination can take place on the dorsal surface instead of the mesial. At the posterior end there may be a real interruption of the CalcS. The CalcS should always be traced to very end, even when that end happens more dorsally.

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