Film: 8×10 in (18×24 cm)

Position of Patient:
-Patient in prone or seated position with arm along the side shoulder lie on the same transverse plane to prevent rotation

Position of Part:
-Affected orbit is center to the cassette with the superciliary ridge and nose rest on table
-IOML is perpendicular to the plane of the film
-MSP is turned 20˚ toward the side being examined
-Immobilize head, respiration suspended for the exposure

Central Ray:
Directed to exit in the affected orbit to the center of the film at an angle of 7˚ caudad

Structure Shown:
-An obstructed and undistorted sphenoid strut at the center of the orbital shadow and separate the optic canal from the superior orbital fissure
-Sphenoid strut lie between sphenoid sinus and combined shadows of the adjacent anterior clinoid process and lesser wing of sphenoid bone
-Superior root of lesser wing of sphenoid bone that forms the roof of optic canal and can be traced medially to the limbus sphenoidalis and lateral to the sphenoid ridges

Evaluation Criteria
-Sphenoid strut should be in the center of the orbit between optic canal and superior orbital fissure
- Entire orbital shadow should be included
-Close beam restriction of orbital region is needed

Film: 8×10 in (18×24 cm)

Position of Patient:
-Patient on seated-erect or prone position, MSP is center to the midline of the table with arm along the side and shoulders lie on the same transverse plane

Position of Part:
-Orbit of interest is center to the midline of the cassette
-Forehead and nose rest on the table
-MSP forms 20˚ angle from the vertical
-IOML is perpendicular to the plane of the film
-Immobilize head, respiration suspended for the exposure

Central Ray:
Exit in the affected orbit at the following angle:
1. 20˚ caudad- demonstrate optic canal and anterior clinoid process
2. 30˚ caudad- demonstrate superior orbital fissure

Structure Shown:
-20˚ caudad demonstrate anterior clinoid process and slightly oblique image of the optic canal at the canter of the orbital shadow
-30˚ caudad demonstrate superior orbital fissure

Evaluation Criteria
-Optic canal lie in the center of the orbit with 20˚ angulation
-Superior orbital fissure is lateral to the optic canal with 30˚ angulation
-Entire orbital shadow should be included
-Close beam restriction of orbital region is needed

Note:
Originally describe which used a double-tube angulation and have been modified by rotating the MSP 20˚. However, basic geometry has remained unchanged.