in P.A skull:
- a- O.M.L perpendicular to the cassette
- b- O.M.Lparallel to the cassette
- c- M.S.P parallel to the cassette
- d- M.S.P perpendicular to the cassette
- e- a&d are correct.
The correct answer is e) a & d are correct.
Here's why:
- PA skull:
This refers to a posteroanterior projection of the skull. In this position, the patient stands facing the X-ray machine with their head turned slightly upwards.
- O.M.L.:
This stands for orbitomeatal line, an imaginary line running from the inner corner of the eye (orbit) to the external auditory meatus (ear canal).
- M.S.P.:
This stands for midsagittal plane, an imaginary plane that divides the body into left and right halves.
Analysis of options:
a) O.M.L perpendicular to the cassette:
This is correct. In a PA skull, the O.M.L should be perpendicular to the cassette (film or detector) to adequately visualize the facial bones and sphenoid sinus.
b) O.M.L parallel to the cassette:
This is incorrect. In a PA skull, a parallel O.M.L would result in poor visualization of the facial bones and sphenoid sinus.
c) M.S.P parallel to the cassette:
This is incorrect. In a PA skull, the M.S.P should be perpendicular to the cassette to properly align the skull and visualize the midline structures.
d) M.S.P perpendicular to the cassette:
This is correct. As mentioned earlier, the M.S.P should be perpendicular to the cassette for proper alignment and visualization.
Therefore, both options a & d are correct, making e) a & d are correct the answer.
It's important to note that these are general guidelines for PA skull radiographs. Specific positioning techniques may vary depending on the clinical indications and the equipment used.
