1. Skull- Special methods

2. Submento-vertical
Remove any movable, radio- opaque material from the patient's skull.
Position of patient and cassette:
The patient may be imaged erect or supine. If the patient is unsteady, then a supine technique is advisable.

3. Supine:
The patient’s shoulders are raised and the neck is hyperextended to bring the vertex of the skull in contact with the table.
The head is adjusted to bring the external auditory meatuses equidistant from the cassette.
The median sagittal plane should be at right-angles to the cassette along its midline.
The IOML should be as near as possible parallel to the cassette.

4. Errect:
The patient sits a short distance away from a vertical Bucky.
The neck is hyperextended to allow the head to fall back until the vertex of the skull makes contact with the centre of the vertical Bucky.
The remainder of the positioning is as described for the supine technique

6. Central Ray
CR is perpendicular to infraorbitomeatal line
Center at 2cm anterior to level of EAMs (midway between angles of mandible)

8. Evaluation of the Image
ID and anatomical markers must be present and correct in the appropriate area of the film
Optimal exposure should penetrate all the bone structures and contrast should be low enough to visualise fully the bone and soft tissue structures. The entire skull should be visualised

9. Signs of excellence
The symmetrical structures should be projected symmetrically about the midline. (condyles of the mandible)
The mandibular symphysis is superimposed with the frontal bone
the mandibular condyles anterior to the petrous pyramids
the foramen magnum should be projected almost circular.
No motion
No tilt or rotation

10. SMV

11. PA axial projection (Haas method)
An alternative view for patients who can’t flex the neck (AP, towne view) but results in magnification of the occipital bone. This view can’t be used when the occipital bone is the area of interest

12. Patient in erect or prone position
Nose and forehead against the table
Flex neck until OML is perpendicular to the film
Midsagittal plane is perpendicular to the film (EAMs at the same distance from the table)

13. Central ray
25 degree cephaled to OML
CR: midsagittal plane at the level of EAM

14. Technical factors
24*30 cm
70-80 kVp
SID: 100 cm
Respiration: suspend respiration

15. Evaluation of the Image
ID and anatomical markers must be present and correct in the appropriate area of the film.
Optimal exposure should penetrate all the bone structures and contrast should be low enough to visualise fully the bone and soft tissue structures
The dorsum sella and posterior clinoid processes should be projected in the almost circular foramen magnum
petrous ridge is projected above the mastoid
The foramen magnum should be projected centrally within the skull outline

16. Evaluation of the Image
Equal distance from foramen magnum to the lateral margin of the skull on both sides
No motion: sharp bony margins

17. Haas method