Upper Limb Positioning Procedure

Questions and Answers

What should be removed from the patient before the procedure?

Rings and watches (correct)

Clothing

Hair accessories

Makeup

The patient should be positioned at the end of the table to avoid discomfort.

True

What should be shielded during the procedure?

gonads

What is the purpose of close collimation?

To reduce exposure to radiation Signup and view all the answers

When performing a bilateral examination of the hands or wrists, it is important to radiograph each side __________ to prevent distortion.

separately Signup and view all the answers

What projection is recommended when joint injury is suspected?

AP projection Signup and view all the answers

In a PA projection for the second to fifth digits, how should the digits be positioned?

Palmar surface down Signup and view all the answers

In a lateral projection, the phalanges should show rotation.

False Signup and view all the answers

In a PA oblique projection, the thumb should be __________ rotated.

externally Signup and view all the answers

What is one advantage of medially rotating the second digit in the STREET method?

It improves recorded detail Signup and view all the answers

What is the purpose of the LEWIS modification in the AP projection of the thumb?

To show the first metacarpal free of soft tissue Signup and view all the answers

Match the following projections with their details:

PA Projection = Palmar surface down, no soft tissue overlap Lateral Projection = True lateral position, no rotation PA Oblique Projection = Thumb rotated 45 degrees STREET Method = Medial rotation for improved detail Signup and view all the answers

Study Notes

General Procedures for Upper Limb Positioning

Remove all radiopaque objects (rings, watches) prior to procedure.
Position patient at the side or end of the table to ensure comfort.
Place the imaging receptor (IR) for optimal patient comfort and accessibility.
Direct central ray perpendicular to the midpoint of the IR.
Perform bilateral examinations of hands or wrists separately to reduce distortion of joint spaces.
Use gonadal shielding to protect sensitive areas.
Employ close collimation to limit radiation exposure.
Include right or left markers for proper identification.

Positioning the Digits (Second to Fifth Digits)

PA Projection

Patient Positioning: Palmar surface down, digits slightly separated.
Central Ray: Perpendicular to PIP joint.
Required Fields:
- Entire digit visible from fingertip to distal metacarpal.
- No soft tissue overlap between adjacent digits.
- No rotation evident; concavity of phalangeal bodies should be even on both sides.
- Open interphalangeal (IP) and metacarpophalangeal (MCP) joint spaces.
Collimation: 1 inch (2.5 cm) on all sides, including proximal to the MCP joint.

Lateral Projection (Lateromedial or Mediolateral)

Patient Positioning: Hand on lateral/radial surface (2nd and 3rd digits) or medial/ulnar surface (4th and 5th digits).
Central Ray: Perpendicular to the PIP joint.
Required Fields:
- True lateral position of digit without rotation.
- Concave anterior surfaces of phalanges visible.
- Open IP joint spaces.

PA Oblique Projection (Lateral Rotation)

Patient Positioning: Hand pronated, rotated 45 degrees laterally (foam wedge may be used).
Central Ray: Perpendicular to PIP joint.
Required Fields:
- Entire digit rotated 45 degrees, concavity present on elevated side.
- No superimposition of structures.
- Open IP and MCP joint spaces.

Street Method (Medial Rotation)

Technique: Medially rotate the second digit from a prone position to enhance visibility of fractures.
Benefit: Improved recorded detail and reduced soft tissue interference.

Positioning the First Digit (Thumb)

AP Projection

Patient Positioning: Arm internally rotated, thumb in medial rotation.
Central Ray: Perpendicular to 1st MCP joint.
Required Fields:
- Entire thumb with trapezium in profile.
- No rotation (concave surfaces of phalangeal and metacarpal bodies).
- Overlap of soft tissue profile.
- Open IP and MCP joint spaces.

Lewis Modification

Adjusted Central Ray: 10-15 degrees toward the wrist along the long axis of the thumb.
Rationale: To visualize the first metacarpal free from soft tissue overlap.

PA Projection for Thumb

Patient Positioning: Thumb's dorsal surface parallel to the IR.
Central Ray: Perpendicular to 1st MCP joint.
Required Fields:
- Entire digit visible with trapezium in profile.
- No rotation evident.
- Overlap of soft tissue profile maintained.

Description

This quiz covers the essential procedures for positioning the upper limb during radiographic exams. It focuses on patient comfort, equipment setup, and proper directing of the central ray. Understanding these concepts is crucial for ensuring effective imaging and minimizing patient strain.