Thumb Lateral
Position the Patient
- Seated at table
- Place hand on IR
- Make a loose fist to move fingers out of the way
- Position thumb in true lateral
Words That Work
“Make a loose fist—like gently holding a small ball—but leave your thumb out. I’ll move your hand until your thumb is resting on its side. Keep your thumb straight and relaxed.”
Lateral thumb positioning
Set Up the Shot
- Center here
- Central ray
- MCP joint
- Include this in the field
- Collimation
- Entire thumb and full metacarpal
- Set the distance
- SID
- 40"
- Check the technique
- Technique
- 55-60 kVp
- Follow facility protocols
Common Pitfalls
- •Not true lateral (thumbnail not in profile)
- •Finger overlap
- •Joints not open
Evaluate the Image
What should be visible?
- Entire thumb
- IP and MCP joints
- Full metacarpal
Does the image pass?
- ✓True lateral (thumbnail seen in profile)
- ✓No finger overlap
- ✓Joints open
- ✓Entire thumb and metacarpal included