Pre-vertebral Fascia
This is a plane of surgical importance.  It is attached to the base of the skull, and extends over the pre-vertebral muscles (longus capitis, rectus capitis and longus colli) to attach distally at T4, just beyond the longus colli muscle.  This forms a plane down which infections can tract.  Thus cervical infections can give rise to a mediastinal abscesses.

Cranio-Vertebral Junction
Assessment of the various bony landmarks seen on lateral radiographs is important in determining normal and abnormal anatomy.  There are a number of radiographic lines used:
 
McRae’s line: from the anterior to the posterior lips of the foramen magnum.  The tip of the odontoid should not project above.

Chamberlain’s line: from the hard palate to its posterior lip and on to the posterior lip of foramen magnum.  The odontoid tip should be less than 3mm above this line.

McGregor’s line: from the posterior lip of the hard palate to the most caudal part of the occipital bone.  The odontoid tip should be less than 4.5mm above this line.