Fig. 6
From: MDCT of acute subaxial cervical spine trauma: a mechanism-based approach
Normal alignment of facet joints on parasagittal CT image (arrows). A facet joint is formed by the obliquely oriented rhomboid-shaped articular processes and overlaps like a roof shingle. The inferior articular process of the cranial vertebra is posterior to the superior articular process of the caudal vertebra. On sagittal images, a facet joint articular surface should be parallel, cranio-caudally symmetrical and congruent; the inferior articular facet should cover the entire articular surface on the superior articular facet below. The facet joint gap should be less than 2 mm