AP elbow X-ray positioning
One of the routine elbow views. The patient sits, the beam passes front to back (AP), straight on to the receptor, and the centring point is the elbow joint, 2 cm below the epicondyles.
By the ScanFlo Editorial Team · Updated
In this section · X-ray positioning
- X-ray positioning guides
- Skull positioning
- Face & sinuses positioning
- Soft tissue neck positioning
- C-spine positioning
- Chest positioning
- Shoulder positioning
- Humerus positioning
- Elbow positioning
- Forearm positioning
- Wrist positioning
- Hand positioning
- T-spine positioning
- Abdomen positioning
- L-spine positioning
- Sacrum & SI joints positioning
- Pelvis positioning
- Hip positioning
- Femur positioning
- Knee positioning
- Tibia & fibula positioning
- Ankle positioning
- Foot positioning
Still being checked: a radiographer is reviewing this guide. If your department does it differently, follow your department.
Patient position
Sitting. Sit the patient at the end of the holder, arm resting on the detector at shoulder height. Elbow fully extended, palm up. A short-armed child: raise the detector on a 10–12 cm support.
Centring & collimation
Central ray
APCentre: the elbow joint, 2 cm below the epicondyles.
Beam: AP, perpendicular to the receptor.
Collimate: the joint with a third of humerus and forearm
Distance, receptor & grid
| Setting | Value | Notes |
|---|---|---|
| SID | 100 cm | |
| Receptor | 18 × 24 cm | portrait |
| Placement | On the holder | No grid |
| Angulation | None | Perpendicular to the receptor |
Marker & breathing
- Marker: R or L marker on the side nearest the detector
- Breathing: No breathing instruction needed.
Exposure by patient size
Treat these as a starting point. Your detector, your generator and the patient in front of you will all move the numbers.
| Patient size | kV | mAs (chart) | mAs (DR default) |
|---|---|---|---|
| XS | 53 | 0.5 | 0.5 |
| S | 53 | 0.63 | 0.5 |
| M | 53 | 0.8 | 0.5 |
| L | 53 | 1.25 | 0.5 |
These start from a classic film-screen chart (53 kV, 10 mAs at 140 cm) and are adjusted for a digital detector at 100 cm. The DR column is what ScanFlo's console suggests; each step up or down changes the mAs by about a quarter.
Image quality checklist
- The joint space is open.
- Epicondyles parallel to the detector.
- The anatomical side marker is visible, correct and clear of the anatomy.
- Collimation borders are visible on all sides, no wider than the area requested.
Faults & how to fix them
| Fault | Cause | Fix |
|---|---|---|
| Joint closed | Elbow flexed | Use the semiflexed views. |
Common questions
- Where do you centre for an elbow AP X-ray?
- The centring point is the elbow joint, 2 cm below the epicondyles.
- What distance and beam angle does an elbow AP need?
- 100 cm from the tube to the receptor. The beam passes front to back (AP), straight on to the receptor.
- What size receptor, and do you need a grid?
- Use an 18 × 24 cm receptor, portrait, on the holder. No grid is needed.
- Where does the lead marker go?
- R or L marker on the side nearest the detector.
- What goes wrong most often on an elbow AP?
- Joint closed. Usual cause: elbow flexed. The fix: use the semiflexed views.
Try it in ScanFlo: the ScanFlo XR X-ray Room, coming soon, lets you set up a elbow ap in a 3D room and score your positioning. See ScanFlo XR →
Written by the ScanFlo team from everyday radiographic practice.