X-RAY OF ORBIT

X-ray Orbit P/A View ((Caldwell))

Orbit PA (Caldwell)

Region: orbit, superior orbital fissure, inferior orbital rim

Pathology: orbital fracture, tumor

SID: 100 cm (40 inches)

Central Ray: beam directed at the nasion with 25˚ caudal angulation

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. Flex the cervical vertebrae enough to make the orbitomeatal line (OML) perpendicular to the IR
4. Lean forehead and nose on the IR to place the nasion at the center of the IR.

Collimation: Include the entire structure of orbit.

Evaluation:

1. All bones constructing the orbit must clearly observed in the image.
2. The bilateral orbits should have symmetrical shapes and sizes with the nasal septum in the center.
3. Petrous ridge should be observed below the superior orbital margin or overlap with the inferior orbital margin.

kVp: 75, mAs: 20

Tip:

1. It is hard to maintain the pose for patient; the inspection must be done in a short time.