The coronal curve refers to the spinal curvature observed in the coronal plane, which is the vertical plane dividing the body into front (anterior) and back (posterior) halves.

In scoliosis:

A coronal curve describes the side-to-side (lateral) deviation of the spine as seen on a frontal X-ray.

It is quantified by the Cobb angle, measured between the most tilted vertebrae above and below the curve apex.