X-RAY OF PNS
Preparation: Wear cotton clothing or change into a gown before the X-ray, Remove metal objects like jewelry.
Region: maxillary sinus, pyramidal ridge, foramen rotundum
Indication/Pathology: fluid retention and inflammatory condition of maxillary sinus, sinusitis, osteomyelitis
FFD: 100 cm (40 inches)
Central Ray: perpendicular beam directed at the acanthion
Respiration: suspended
Position:
1. The patient is placed in an erect
position, in a sitting position, or in a prone position.
2. Align the midsagittal plane (MSP) of head to the vertical axis crossing the
center of the image receptor (IR).
3. Extend the cervical
vertebrae to adjust the angle of the orbitomeatal
line (OML) and the IR to 37˚.
4. Lean the chin on the IR and place the acanthion at
the center of the IR.
Evaluation:
1. Frontal
sinus and maxillary
sinus must be placed at the center of image and their contours should
be clearly demonstrated.
2. The superior margin of petrous
ridge should overlap the inferior margin of maxillary sinus.
3. Bilateral orbits
should be symmetric with nasal
septum at the center.
Factor: kVp:80, mAs:28
Tip:
1. When patient cannot be in prone
position, implement Paranasal Sinus Acanthioparietal (Reverse Waters)
Projection with patient in supine position.
2. To observe air fluid level inside of paranasal sinus, it should be taken a
period of time after changing patient's position considering movement of sticky
fluid.
3. When to observe sphenoid
sinus, implement Paranasal Sinus Open Mouth Waters (Pirie) Projection.
4. If the position is correct, the distance from apex of nose to image receptor
(IR) is usually around 2 cm.
5. It is hard to maintain the pose for patient; the inspection must be done in
a short time.
6. Cone is recommended to use for this inspection.
