SKULL X RAY ( Cranium) PA PROJECTION
SKULL X RAY ANATOMIC STRUCTURES
Posterior ethmoidal air cells
Petrous portions of temporal bones
SUITABLE FILM SIZE FOR SKULL X RAY
10 X 12 in. (24 X 30 cm), lengthwise
PATIENT POSITION OF SKULL X RAY
Place patient prone (face down) on table Or Have patient stand or sit facing vertical grid device
For support, place patient’s hands beside head (far enough away to prevent superimposition) on table or grid device.
Align midsagittal plane of body to midline of table Adjust shoulders in same transverse plane.
Place lead shield over patient to protect gonads.
PART POSITION OF SKULL X RAY
Place patient’s forehead and nose on table or grid device Align midsagittal plane of head perpendicular to plane of film and in midline of table or grid device.
Adjust head to place orbitomeatal line perpendicular to planc of film.
*To prevent rotation of the head, place fingertips on mastoid processes and lateral rims of orbits, and be sure they are the same distance from table top or grid device on each side.
Direct central ray perpendicular to plane of film to exit at nasion. cnter cassette (in Bucky tray) to central ray
Instruct patient to suspend respiration for exposture
Anterior and lateral walls of cranium should be demonstrated Petrous bones should completely fill orbit
Distance from lateral orbital margin to lateral margin of skull should be equal on both sides Posterior ethmoidal ear cells should be seen
Crista galli should be visualized
SKULL X RAY LATERAL PROJECTION
Anterior and posterior clinoid processes
Squamous portions of parietal and temporal bone
10 x 12 in. (24 X 30 cm), crosswise
Place patient in semiprone scated or crect position with affected side closer to table or vertical grid device.If semiprone, have patient rest on forearm and
knee of elevated side.
If patient in semiprone position for a lefl lateral projection, the right side of the patient is elevated
when we place patient in semiprone for cranial lateral view patient’s right side demonstrated
and the patient is resting on the right forcarm and knee, for a right lateral projection, the left side of the patient is elevated and the patient is resting on
the left forearm and knee. If seated or erect, rotate patient 15 from PA position Placc head in lateral position with external auditory meatus in midline of table or grid de.
vice.Place lead shield over patient to protect gonads
Adjust head to place midsagittal plane parallel to plane of film
Adjust head to place interpupillary line perpendicular to plane of film.
NOTE: For skull x ray Radiolucent support may be placer” side of mandible in semiprone position to prevent it from sagging djust degree of flexion of head to place
infraorbitomcatal line-parallal to transverse axis of table or grid device.to prevent rotation feel for inion(external occipital protubarance ) with one hand and glabella with other hand and adjust head so that these two point are same distance from table top or grid device
Direct central ray perpendicular to plane of film nat a point 2 in. (5 cm) superior to external auditory meatus. If sella turcica is area of interest, direct central
ray 3/4 in. anterior and 3/4 in. superior to external auditory meatus. Center cassette (in Bucky tray) to central ray.
Instruct patient to suspend respiration for exposure.
Lateral walls of cranium should be demonstrated There should be superimposition of orbital roofs, mandibular rami, external auditory meati, and temporomandibular joints.
Sella turcica, anterior and posterior clinoid processes, and dorsum sellae should be demonstrated without rotation
Sphenoid sinuses should be visualized