Lateral Thoracic is a radiography positioning projection of the Spine. Lateral recumbent, CR perpendicular to T7. Breathing technique. The centering point is located t7 vertebra, mid-chest level.. The central ray is perpendicular to ir at t7 level.. Image-quality criteria include all thoracic vertebrae t1-t12 clearly visualized., intervertebral disc spaces open symmetrically.. Standard exposure ranges from 80 to 90 kVp, 50 to 100 mAs, at an SID of 40 inches (102 cm).
Anatomy demonstrated
- Thoracic vertebral bodies T1-T12.
- Intervertebral disc spaces.
- Thoracic spinous processes.
- Facet joints of thoracic spine.
- Thoracic kyphotic curve.
Patient preparation
- Verify patient identity using two identifiers.
- Remove jewelry and radiopaque breast devices.
- Lateral recumbent position, true lateral alignment.
- Hips and shoulders perpendicular to table.
- Head supported comfortably in alignment.
Position & centering point
T7 vertebra, mid-chest level.
Central ray
Perpendicular to IR at T7 level.
Exposure / technique
- kVp
- 80–90
- mAs
- 50–100
- SID
- 40" (102 cm)
- Notes
- Use breathing technique to blur ribs. Slow, even breathing.
Image-quality criteria
- All thoracic vertebrae T1-T12 clearly visualized.
- Intervertebral disc spaces open symmetrically.
- Vertebral bodies superimposed without rotation.
- Spinous processes aligned posteriorly.
- Thoracic kyphosis demonstrated.
Common errors / ARRT traps
- 1 Rotation shifts vertebral bodies creating illusion of offset.
- 2 Insufficient breathing blur leaves rib superimposition.
- 3 Arms held up shift shoulders into the field and obscure T1.
- 4 CR not at T7 misses mid-thoracic structures.
Clinical indications
- Thoracic spine trauma evaluation in lateral patient.
- Assessment of vertebral alignment and disc degeneration.
- Evaluation of kyphotic deformity.
- Post-operative thoracic fusion follow-up.
Aligned to the 2025 ARRT Content Specifications.