Skull - Lateral Horizontal Ray

Radiographic Positioning

Adult

Other related pages of interest Applied Radiography Radiographic Anatomy Radiographic Protocols

Name of projection	Skull - Lateral Horizontal Ray (Supine)
Area Covered	Entire skull
Pathology shown	Fractures and pathologies of the skull
Radiographic Anatomy	Skull Radiographic Anatomy
IR Size & Orientation	24 x 30 cm Landscape (with the longest side parallel to the table top)
Film / Screen Combination	Regular (CR and DR as recommended by manufacturer)
Bucky / Grid	Moving or Stationary Grid
Filter	No
Exposure	70 kVp 16 mAs
FFD / SID	100 cm
Central Ray	Directed to 5 cm superior to the EAM (External Auditory Meatus) Perpendicular to the film
Collimation	Outer skin margins of the skull
Markers	Inferior and Anterior Marker orientation AP, indicating the side of the skull closest to the film
Shielding	Gonadal (check your department's policy guidelines)
Respiration	Suspended
Positioning	The patient typically presents in a supine position in trauma cases If the patient has not been cleared of a cervical spine injury, do not reposition the patient Position the film and grid so that they are parallel to the midsaggital plane of the skull Angle the central ray so that it is Perpendicular to the film and grid (and, therefore, also the midsaggital plane) Parallel to the interpupillary line
Critique PACEMAN	Positioning No rotation is evidenced by The greater wings of sphenoid are superimposed (see notes below) No tilt is evidenced by There is superimposition of the superior orbital plates of the frontal bone Area Covered Entire skull Collimation Centre: 5 cm (2 inches) superior to the EAM Shutter A: Open to include the skin margins of the top of skull superiorly, and the base of the occiput inferiorly Shutter B: Open to include the skin margins of the anterior and posterior skull Exposure Assess for adequate penetration of the thickest part of the skull seen on the lateral view Bony trabecular patterns and cortical outlines are sharply defined Soft tissues are visualised
Special Notes	Determining the direction of head rotation Identify the greater wing of sphenoid which is closer to the film. Compared to the other greater wing of sphenoid it will appear sharper and less magnified. Look at the position of the one furthest from the film to decide how to reposition the film and grid.