Towne's view of the skull X-ray positioning (occiput)
An extra skull view, used when a routine one is not enough. The patient lies on their back, the beam passes front to back (AP), tilted 30° towards the feet, and the centring point is 7–8 cm above the nasion on the midline.
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
Supine. Remove dentures, earrings, hair clips and anything in the hair. Supine, head flat on a thin pad, orbitomeatal line perpendicular to the table.
Centring & collimation
Central ray
APCentre: 7–8 cm above the nasion on the midline.
Beam: AP, angled 30° caudad.
Collimate: the occiput and the whole vault
Distance, receptor & grid
| Setting | Value | Notes |
|---|---|---|
| SID | 100 cm | |
| Receptor | 24 × 30 cm | portrait |
| Placement | Table bucky | Grid in |
| Angulation | 30° | caudad |
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 | 70 | 10 | 4 |
| S | 70 | 16 | 6.3 |
| M | 70 | 20 | 8 |
| L | 70 | 32 | 12.5 |
These start from a classic film-screen chart (70 kV, 40 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 dorsum sellae is projected within the foramen magnum.
- Occipital bone and petrous ridges symmetric.
- 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 |
|---|---|---|
| Dorsum sellae above the foramen magnum | Too little caudal angle or chin up | Tuck the chin and check 30° caudad. |
Common questions
- Where do you centre for a skull (occiput) Towne's X-ray?
- The centring point is 7–8 cm above the nasion on the midline.
- What distance and beam angle does a skull (occiput) Towne's need?
- 100 cm from the tube to the receptor. The beam passes front to back (AP), tilted 30° towards the feet.
- What size receptor, and do you need a grid?
- Use a 24 × 30 cm receptor, portrait, in the table bucky. A 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 a skull (occiput) Towne's?
- Dorsum sellae above the foramen magnum. Usual cause: too little caudal angle or chin up. The fix: tuck the chin and check 30° caudad.
Try it in ScanFlo: the ScanFlo XR X-ray Room, coming soon, lets you set up a skull (occiput) towne's in a 3D room and score your positioning. See ScanFlo XR →
Written by the ScanFlo team from everyday radiographic practice.