HORIZONTAL CENTRAL RAY

This is a unique projection where the central ray is directed horizontally towards a cassette placed vertically. It is essential to correctly align the tube to maintain perpendicularity with the plate.

Exposure Factors

55-65
Kilovoltage (kV)
10-15
Milliampere-seconds (mAs)
Broad Focus
Focal Spot Type
100-110 cm
Source-Image Distance

Equipment: Without bucky (vertical plate). Position: Standing (Orthostatic).

Cassette Size

24 × 30 cm
Longitudinally (Vertical)

Visible Anatomical Structures

Plantar Arches

Medial and lateral longitudinal arches

Hindfoot

Calcaneus and Talus profile

Midfoot

Navicular, Cuboid, and Cuneiforms

Forefoot

Metatarsals and phalanges (superimposed)

Patient Positioning

Patient standing (upright) on a radiolucent block or specialized platform
Weight distributed equally on both feet
Cassette placed vertically between the feet (for medial-lateral) or on the side
The foot of interest must be perfectly lateral to the cassette
Foot centered on the vertical plate
Ensure the patient remains stable during the exposure
The platform must allow the foot to be elevated so the ray can pass horizontally through the sole level

CENTERING POINT

Base of the 3rd Metatarsal

Level of the midfoot to include both the hindfoot and forefoot

Central Ray Direction

Horizontal and perpendicular to the cassette

HORIZONTAL PERPENDICULAR

Direction: Completely horizontal, parallel to the floor

Entry: Lateral side of the foot (Medio-lateral projection)

Exit: Medial side, towards the vertical cassette

Angulation: 0° (Strictly horizontal)

Patient Instructions

"Don't move, keep your weight on both feet"

Look straight ahead - Maintain balance without moving the feet

Clinical Indications

Flat foot (Pes Planus)
High arch (Pes Cavus)
Plantar Fasciitis
Biomechanical assessment
Bone measurements

Safety Considerations

This projection requires closer technical supervision due to the unusual position