Length (L): Distance from the tip of the
dorsum sellae to that of the tuberculum sellae.
Those tumours related to the most rostral extension of the notochord in the
dorsum sellae will present as sellar and parasellar chordomas.
Dorsum sellae (DS): A square portion of bone on the body of the sphenoid posterior to the sella turcica or hypophysial fossa.
According to this method, the ITA was outlined by dorsum sellae cranially, internal table of the occipital bone dorsally, the clivus ventrally and the McRae line caudally, whereas, STA was the area between dorsum sellae and the internal tables of the bones in the supratentorial compartment, excluding the sella turcica.
Its limits are the superior orbital fissure (anterior), the dorsum sellae (posterior), the superior margin of the maxillary nerve (inferior), and the diaphragma sellae (superior).
The posterior petroclinoid dural fold (superior), the dura of the medial edge of the trigeminal porus (lateral), the upper margim of petroclival fissure (inferior) and the lateral edge of the dorsum sellae (medial).
If BA lies lateral to the margin of the cavus or
dorsum sellae or it bifurcates above the plane of the superasellar cisternae, it may be considered elongated (from the Greek dolichas) and an ectasy means distention and is considered when the diameter of the artery is greater 4.
His cranial radiographs revealed an enlarged sellae turcica and destruction of
dorsum sellae.
The posterior boundary of the pituitary fossa is formed by the
dorsum sellae, the supero-lateral angles of which are raised to form the posterior clinoid process.
It slopes backward and downward from the
dorsum sellae to the foramen magnum in the occipital bone.
The
dorsum sellae were eroded, but posterior and anterior extension of the tumor was minimal (Figure 1, A).
These variations are oblique Anterior wall, double contour of floor, sella turcica bridging, irregularity in posterior part of
dorsum sellae, pyramidal shape of the dorsum and double contour of the floor.
