Study of the Thumb (First Digit)

PA Projection

1. Seat the patient at the end of the table;
2. Lower limbs away from the radiation;
3. Hand in profile position;
4. The remaining digits away from the thumb.

Central ray is perpendicular to the interphalangeal joint or metacarpophalangeal.

 

Evaluation Criteria:

• No rotation of the thumb;
• View all the digit including the metacarpophalangeal (MCP) joint;
• Open interphalangeal and MCP joint spaces without overlap of the bones;
• Digit centered and aligned in the center of collimation;
• Not visualization the soft tissue of adjacent fingers;
• Appropriate exposure values (visualization of the all bony trabeculation and soft tissue).

 

Lateral Projection

1. Seat the patient at the end of the table;
2. Lower limbs remote from the radiation;
3. Support the forearm and arm;
4. The side of the thumb resting on the IP;
5. Flexion of the fingers.

Central ray is perpendicular to the interphalangeal joint or metacarpophalangeal.

 

Evaluation Criteria:

• Thumb strictly in profile;
• View all the digit including the metacarpophalangeal joint;
• Open interphalangeal and MCP joint spaces;
• Finger centered and aligned in the center of collimation;
• Not visualization the soft tissue of adjacent fingers;
• Appropriate exposure values (visualization of the all bony trabeculation and soft tissue).