MODIFIED PARIETOACANTHIAL PROJECTION: FACIAL BONE X-RAY

 

MODIFIED WATERS METHOD : FACIAL BONES

Pathology Demonstrated:

• Orbital fissures like blow out and neoplastic / inflammatory processes are shown. Foreign bodies in the eye also may be demonstrated in this position.

Technical Factors:

• IR size 18 x 24 cm (8 x 10 inches), lengthwise
• Moving or stationary grid
• 70 to 80 kV range
• Small focal spot
• mAs 18

Patient Position:

Modified Waters  OML 55 degrees

• Remove all metallic or plastic objects from the head and neck. Patient position is erect or prone but erect is preferred is patient's condition allows.

Part Position:

• Extend neck chin and nose against table or bucky surface.
• Adjust head until Lips Meatal Line (LML) is perpendicular; Orbitomeatal Line (OML) forms a 55 degree angle with the IR.
• Position Mid Sagital Plane (MSP) perpendicular to the middle of the grid or the table or upright bucky surface. Ensure no rotation ot tilt of hand.

Central Ray:

• Align Central Ray perpendicular, centered to exit at acanthion.
• Center Image receptor to Central ray

Collimation:

• Collimate to within 1 inch or 2.5 cm of facial bones.

Respiration of patient:

• Suspend respiration during exposure.

Radiographic Criteria:

Structure shown:

Modified Parietoacanthial (Waters)

• Orbital floor (plates) are visible with this projection, which also provides a less distorted view of the entire orbital rims than a parietoacanthial  (Waters Method) projection.

Position:

• Correct position / CR angulation is indicated by petrous ridges projected into the lower half on the maxillary sinuses, below the inferior orbital rim.
• No rotation of the cranium is indicated by equal distance from the midlateral orbital margin to the outer skull margin on each side.

Collimation and Central Ray:

• The inferior orbital rim should be located at the center of the image.
• The entire orbital rim and maxillary bones should be included in the collimated field.

Exposure Criteria:

• Contrast and density are sufficient to visualize the orbital floors.
• Sharp bony margins indicated no motion.