Cranium Exam

How many bones make up the cranium? The facial bones region?

Cranium is 8 bones, facial is 14 bones

What is the name of the suture that separates the parietal bones from the occipital?

Lambdoidal Suture

What structure is located within the sella turcica?

Pituitary gland

Which cranial bone contains the EAM?

Temporal

What is the joint classification of the cranial sutures in the adult?

Synarthrodial

Which aspect of the cranium contains the orbital plates?

Frontal Bone

What is another, formal term for the inion?

External occipital protuberance

Part one: Calculate the cephalic index for the following measurements: 15 cm breath ; 20 cm length.

Part two: What is the skull classification of the skull?

C.I. of 75.0 ; Dolichocephalic

What are the two cortical bone layers of cranium termed? What is the layer of medullary bone between them termed?

The outer and inner tables. Diploe.

For an SMV projection of the cranial base, the central ray should always be perpendicular to the _____ line.

infraorbitomeatal

The central ray and center of the image receptor position for a lateral projection of the cranium is _____ inch(es) _____ the EAM.

2; above

The central-ray angle for the PA axial (Caldwell) projection of the skull is:

15 degrees caudad.

Which of the following cranial landmarks (structures) are most accurate to determine rotation on a lateral skull projection?

Greater wings of sphenoid

Which of the following is true regarding the lateral projection of the skull?

1. The midsagittal plane of the head is parallel to the image receptor.

2. The interpupillary line is perpendicular to the image receptor.

3. The mentomeatal line is parallel with the bottom edge of the image receptor.

1 and 2

What specific positioning error produces asymmetry of the petrous bones as seen on an AP axial projection of the cranium?

Rotation

Which positioning plane is placed parallel to the edge of the IR to control flexion and extension for a lateral projection of the cranium?

GAL

How many degrees difference is there between the OML and IOML positioning lines?

7

Which region of the skull is fractured with a tripod fracture?

Malar or zygomatic bone

A TIA refers to:

a mild form of a stroke

Which radiographic position could provide an indication of a basilar skull fracture?

Horizontal beam lateral

Which form of pathology often requires an interventricular shunt to relieve intracranial pressure?

Hydrocephalus

How much and the direction is the CR angle for an AP axial projection with the OML perpendicular to IR?

30 degrees caudad

Where is the CR centered for an AP axial projection (Modified Townes) of the cranium?

2 1/2 " above glabella

Which skull suture is found between the frontal and parietal bones?

Coronal

Which of the following positioning lines is parallel to the image receptor for a lateral projection of the skull?

Mid-sagittal plane

Which bone has condyles that articulate with the atlas of the cervical spine?

Occipital

Which line should be placed perpendicular to the plane of the image receptor for the PA Caldwell projection?

Orbitomeatal line

For a PA Caldwell method, which of following factors would lead to the petrous ridges being projected at the level of the infraorbital margin?

Excessive extension

What is the C.I. equation?

(Breath x 100)/ Length

Dociocephalic

75.9 or below

Mesocephalic

76.0 to 80.9

Brachiocephalic

81.0 or above

What stroke is more common?

Ischemic instead of hemmoragic

Blowout fracture?

Bottom of Orbit

Comminuted Fracture?

Inner and Outer Table