Indications for imaging
Trauma, But see RCR recommendations.
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Anatomy Demonstrated
Frontal bone, orbits, frontal and ethmoid sinuses
Skull 20 degree Occipito Frontal Anatomy
Meschan, I. 1955 An Atlas of Normal Radiographic Anatomy
Saunders, London
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Basic Patient Position
The patient lies supine on the trolley or x-ray table, the midsaggital
plane central.
The patients head is positioned so that the interpupilary line
is parallel to the film.
*The neck is flexed depressing the chin until the radiographic
baseline (RBL) is at 90 degrees to the film, * Not possible if
there is a possible cervical injury)
A small pad may be needed under the occiput or beneath the
cassette.
Skull 20 degree Occipito Frontal
Patient Position
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Radiation protection
Avoid irradiation of the thyroid region, direct lead rubber
protection my be used.
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Central Ray
The vertical central ray is angled 20 degrees cranially and centered
to the glabella.
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Exposure Factors
| Kv |
mAS |
FFD (cm) |
Grid |
Focus |
AEC |
Cassette |
| 85 |
25 |
100 |
Yes Stationary |
Fine |
No |
24 x 30 cm |
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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 cranial vault should be visible.
The orbital margins should be equidistant from the cranial
margins laterally (no rotation)
The petrous ridges should be projected into the lower quarter or
below the inferior orbital margins.
Skull 20 degree Occipito Frontal Radiograph
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Related Projections
Skull Fronto Occipital 30
Skull Lateral Horizontal Ray
Skull Sub Mento Vertical
Facial Bones,
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Additional modalities
CT
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