midsagittal

The midsagittal plane, also called the median sagittal plane, is a vertical anatomical plane that divides the body into left and right halves. It passes through the midline, equidistant from both sides, making it the specific sagittal plane that yields equal halves.

More generally, sagittal planes are vertical planes that run from front to back; the midsagittal plane is the central member of this family. Planes parallel to it that are offset from the midline are also sagittal, but they do not bisect the body into equal halves.

Clinically, midsagittal sections are used in anatomy and imaging to study midline structures and symmetry. Imaging modalities such as MRI and CT can acquire slices along the midsagittal plane, revealing structures such as the corpus callosum in the brain and the alignment of midline spinal structures.

Individuals are not perfectly symmetrical; a true midsagittal plane is an idealization, but many structures are described with reference to the midsagittal position when assessing symmetry or pathology.

Etymology: midsagittal derives from Latin medius (middle) and sagittalis (of the arrow or of the sagittal plane).