parasagittal

Parasagittal is an anatomical term used to describe a plane, section, or structure that runs parallel to the sagittal plane and lies offset from the body’s midline. The sagittal plane extends from front to back, and the midsagittal (or median) plane divides the body into equal left and right halves. In contrast, a parasagittal plane is nearby but situated laterally, producing sections that are not exactly equal on both sides.

The term is widely used to describe orientation in various parts of the body, including the brain, spine, and abdomen. In neuroanatomy, parasagittal describes regions or slices located beside the longitudinal fissure that separates the cerebral hemispheres. In imaging and surgical contexts, parasagittal sections or landmarks refer to locations parallel to the midline but offset toward one side, which helps in diagnosing unilateral abnormalities or planning targeted interventions.

In practical use, parasagittal conveys a relative position rather than an exact distance from the midline. It is often paired with qualifiers such as left or right to specify the side. The concept is distinct from the midsagittal plane, which passes directly through the midline. Etymologically, para- means beside, and sagittal derives from sagitt-, meaning arrow or. The term thus indicates proximity to the sagittal plane without being on it.