ARRT Upper Extremity Procedures 2 — Questions and Answers
Question 1: Which projection of the elbow best demonstrates the radial head free of superimposition?
- AP projection
- Lateral projection
- Medial oblique projection
- Lateral oblique (external rotation) projection (Correct answer)
Correct answer: Lateral oblique (external rotation) projection
The lateral oblique (external rotation) projection rotates the forearm outward to project the radial head free of the ulna.
Question 2: For an AP projection of the humerus, the epicondyles should be:
- Perpendicular to the image receptor
- Parallel to the image receptor (Correct answer)
- Rotated 15 degrees internally
- Rotated 15 degrees externally
Correct answer: Parallel to the image receptor
In the AP humerus projection, the epicondyles are parallel to the IR so both the medial and lateral aspects are seen in profile.
Question 3: A Norgaard method (ball-catcher's position) radiograph is primarily used to evaluate:
- Carpal tunnel syndrome
- Early rheumatoid arthritis changes in the MCP joints (Correct answer)
- Scaphoid fractures
- Acromioclavicular separation
Correct answer: Early rheumatoid arthritis changes in the MCP joints
The Norgaard (ball-catcher's) position places both hands in partial supination to detect early erosive changes of rheumatoid arthritis at the MCP joints.
Question 4: What is the recommended central ray angulation for the carpal canal (Gaynor-Hart) projection?
- Perpendicular to the IR
- 25–30° toward the fingers (Correct answer)
- 25–30° toward the wrist
- 15° toward the elbow
Correct answer: 25–30° toward the fingers
The carpal canal projection angles the CR 25–30° toward the fingers to project the palmar surface of the carpal bones and tunnel structures.
Question 5: Which carpal bone is most commonly fractured and is best demonstrated in the scaphoid (ulnar deviation) position?
- Lunate
- Triquetrum
- Scaphoid (Correct answer)
- Hamate
Correct answer: Scaphoid
The scaphoid is the most frequently fractured carpal bone; ulnar deviation elongates it and removes foreshortening for better visualization.
Question 6: For a lateral projection of the wrist, proper positioning requires that the:
- Radius and ulna are superimposed (Correct answer)
- Radius and ulna are separated by at least 1 cm
- Hand is pronated
- Elbow is fully extended
Correct answer: Radius and ulna are superimposed
A true lateral wrist has the radius and ulna directly superimposed, confirming no rotation.
Question 7: When radiographing a digit in the PA oblique position, the finger is typically rotated:
- 90° from PA
- 45° from PA (Correct answer)
- 30° from PA
- 60° from PA
Correct answer: 45° from PA
The PA oblique digit projection uses a 45° rotation from PA to open the joint spaces and show both cortices of the phalanges.
ARRT Upper Extremity Procedures 2
Which projection of the elbow best demonstrates the radial head free of superimposition?