Radiological Anatomy: Calcarine Sulcus

OVERVIEW

This page is dedicated to covering how the calcarine sulcus will appear across different radiological studies. It is an important anatomical structure in the brain.

The calcarine sulcus is an important anatomical landmark in the brain (image source)
FINDING THE CALCARINE SULCUS ON SAGITTAl CROSS SECTIONS: Y-SIGN

Often times on sagittal sections near the midline of the brain, the parieto-occipital sulcus will join with the calcarine sulcus to form what looks like a “Y”. The image below depicts shows this characteristic “Y-sign”.

The images above are from a T1 weighted MRI of the head without contrast. One image is shown in the axial plane (top left) and two identical images are shown in the sagittal plane (middle, right). Both sagittal images are identical, except the right sided image has been annotated to show the location of the parieto-occipital sulcus (red line) and the calcarine sulcus (blue line). The axial section shown demonstrates the level at which the sagittal sections are found anatomically (white line). At this level, the parieto-occipital sulcus and the calcarine sulcus join together to form a characteristic “Y” shape.

HERE ARE SOME EXAMPLES OF THIS SIGN SEEN ON A NON-CONTRAST HEAD CT-SCAN. CLICK THE THUMBNAILS TO VIEW THEM.

HERE ARE SOME EXAMPLES OF THIS SIGN SEEN ON A T1 WEIGHTED HEAD MRI WITHOUT CONTRAST. CLICK THE THUMBNAILS TO VIEW THEM.

APPEARANCE OF THE CALCARINE SULCUS ON AXIAL CROSS SECTIONS

The calcarine sulcus can be seen on axial sections of the brain, however there is not a clear characteristic appearance of this structure on this section. Looking at the sagittal cross sections of the brain will help to locate this sulcus on axial images. An example of how this sulcus looks on axial imaging is shown below.

The images above are from a T1 weighted MRI of the head without contrast. One image is shown in the sagittal plane (top left) and two identical images are shown in the axial plane (middle, right). Both axial images are identical, except the right sided image has been annotated to show the location of the calcarine sulcus (blue line). The sagittal section shown demonstrates the level at which the axial sections are found anatomically (white line). At this level, the calcarine sulcus can be visualized, but does not necessarily have any characteristic appearance that allows it to be identified without looking at the sagittal view of the brain.

HERE ARE SOME EXAMPLES OF THIS SULCUS SEEN ON A NON-CONTRAST HEAD CT-SCAN (AXIAL ORIENTATION). CLICK THE THUMBNAILS TO VIEW THEM.

HERE ARE SOME EXAMPLES OF THIS SULCUS SEEN ON A T1 WEIGHTED HEAD MRI WITHOUT CONTRAST (AXIAL ORIENTATION). CLICK THE THUMBNAILS TO VIEW THEM.

ACKNOWLEDGEMENTS

A very special thanks goes to Dr. Pierre Sasson who made this page possible with his expertise and insight.

 

Page Updated: 11.25.2017