How To Tell If A Skull Radiograph is Acceptable!

PA or AP

1. Are the exposure factors correct? (frontal bone should be properly penetrated without excessive density at lateral borders of skull, proper contrast)

2. Is the entire cranial perimeter included? (all of mandible is not necessary- that is another exam!)

3. Is there rotation? (distance from lateral border of skull to lateral border of orbit should be equal on both sides)

4. Is there tilt? (Head leaning to left or right side)

5. Proper extension/flexion? (petrous ridges should fill orbit)

PA AXIAL (Caldwell) (This is just a PA with 15 degree caudad angle of CR)

Same criteria as PA or AP above except #5 -petrous ridges should lie in lower 1/3 of orbit!

Lateral

1. Are exposure factors correct? (Proper contrast and density)

2. Is the whole cranium on image? (all of mandible is not necessary!)

3. Is there rotation? (Rami of mandible should be superimposed, TMJ Superimposed, sella in profile) EAM,& mastoids superimosed

4. Is there tilt? (Orbital roofs must be superimposed, sella in profile)

5. Proper extension/Flexion? (Mandible should not overlap C-spine) (technically, IOML should be parallel with long-axis of image) Page 2 How to tell if the Radiograph is Acceptable

Towne (AP Axial)

1. Are the exposure factors correct?

2. Is the entire cranium on image? (Again, Mandible not necessary!)

3. Rotation? (Distance from lateral border of skull to lateral border of foramen magnum should be equal on both sides. Petrous pyramids should be symmetrical)

4. Tilt? (Does head look like its cocked to one side or the other?

5. Flex/Extension? (Dorsum sellae and post. Clinoid processes should be seen in foramen magnum. Too flexed, C-1 is seen in foramen, too extended- don’t see sellae and processes in foramen, may not even see foramen magnum!)

SMV (Basal)

1. Are exposure factors correct?

2. Is entire cranium on image?

3. Rotation? (Midsagital plane should be parallel with lengthwise axis of film)

4. Tilt? (Distance from lateral border of skull to mand. Condyles should be equal on both sides)

5. Flex/extention? (too flexed- mental protuberance won’t super-impose anterior frontal bone. Too extended-never have this problem on real pt., on phantom-mental protuburance will over-extend frontal bone.

6/7/08