Ribs Anterior PA is a radiography positioning projection of the Thorax. PA anterior ribs, erect. SID 40". Full inspiration. The centering point is located level of t7 (mid-sternum). patient erect, anterior chest against ir.. The central ray is perpendicular to ir, horizontal at the level of t7.. Image-quality criteria include anterior ribs clearly demonstrated with full costochondral junctions visible., costochondral junctions projected clear of the rib shafts.. Standard exposure ranges from 65 to 75 kVp, 12 to 20 mAs, at an SID of 40 inches (102 cm).
Anatomy demonstrated
- Anterior aspects of ribs 1-12.
- Costochondral junctions.
- Costal cartilages.
- Sternum and sternal articulations.
- Mediastinal contours.
- Clavicles and shoulder girdle.
Patient preparation
- Verify patient identity using two identifiers.
- Remove all radiopaque objects from the chest and trunk.
- Position patient erect facing away from tube, anterior chest against IR.
- Instruct patient to take a deep breath in and hold for the exposure.
- Ensure shoulders are relaxed and posterior surface of chest flat against IR.
Position & centering point
Level of T7 (mid-sternum). Patient erect, anterior chest against IR.
Central ray
Perpendicular to IR, horizontal at the level of T7.
Exposure / technique
- kVp
- 65–75
- mAs
- 12–20
- SID
- 40" (102 cm)
- Notes
- Grid required. Full inspiration held throughout the exposure.
Image-quality criteria
- Anterior ribs clearly demonstrated with full costochondral junctions visible.
- Costochondral junctions projected clear of the rib shafts.
- Ribs projected parallel without foreshortening.
- Sternum superimposed by the vertebral column.
- No rotation of the thorax; symmetric rib pairs on both sides.
- Full lung expansion demonstrated.
Common errors / ARRT traps
- 1 Rotation tilts the ribs and obscures the costochondral junctions.
- 2 Inadequate inspiration flattens the diaphragm and reduces space.
- 3 Patient not positioned with anterior chest flush against IR.
- 4 Shoulders forward or upward foreshorten the upper ribs.
- 5 CR aimed above or below T7 clips anatomical structures.
Clinical indications
- Evaluation of costochondritis or costochondral junction tenderness.
- Assessment of anterior rib fractures.
- Follow-up of known anterior rib pathology.
- Detailed costochondral junction anatomy evaluation.
Aligned to the 2025 ARRT Content Specifications.