ARRT Spine and Pelvis Procedures 4 — Questions and Answers
Question 1: For the AP projection of the coccyx, the CR is directed:
- 10 degrees cephalad
- 10 degrees caudad (Correct answer)
- Perpendicular to the IR
- 20 degrees cephalad
Correct answer: 10 degrees caudad
The AP coccyx requires a 10-degree caudad CR angulation to project the coccyx free of the pubic symphysis.
Question 2: The Fuchs method is used to demonstrate which structure?
- Sacroiliac joints
- Dens (odontoid process) in extension (Correct answer)
- Lumbar pars interarticularis
- C7-T1 junction
Correct answer: Dens (odontoid process) in extension
The Fuchs method is an AP axial projection with the neck hyperextended, projecting the dens through the foramen magnum.
Question 3: A patient with suspected cervical spine trauma is brought in on a backboard. The first radiograph obtained should be:
- AP projection
- Open-mouth odontoid view
- Cross-table lateral projection (Correct answer)
- Swimmers lateral view
Correct answer: Cross-table lateral projection
The cross-table lateral projection is the first and most critical view in trauma because it can be obtained without moving the patient and demonstrates alignment, fractures, and foreign bodies.
Question 4: To reduce the gonadal dose during AP spine radiography on a female patient, the technologist should:
- Use a higher kVp technique
- Apply gonadal shielding over the symphysis pubis
- Collimate tightly and position shield inferior to the area of interest (Correct answer)
- Increase the SID to 72 inches
Correct answer: Collimate tightly and position shield inferior to the area of interest
Tight collimation and proper contact shielding placed just inferior to the primary beam field reduces scatter and primary beam dose to the ovaries.
Question 5: The swimmers lateral (Twining method) is used to demonstrate which region?
- Lumbar spine
- Sacroiliac joints
- C7-T1 junction (Correct answer)
- Upper cervical spine
Correct answer: C7-T1 junction
The Twining (swimmers) lateral is specifically designed to demonstrate the C7-T1 cervicothoracic junction when it is obscured by the shoulders on a standard lateral view.
Question 6: For an AP oblique projection of the sacroiliac joints, the body is rotated:
- 10-15 degrees from supine
- 25-30 degrees from supine (Correct answer)
- 45 degrees from supine
- 60 degrees from supine
Correct answer: 25-30 degrees from supine
A 25-30 degree body rotation from the supine position places the sacroiliac joint parallel to the IR, opening the joint space for the AP oblique projection.
Question 7: Which positioning error is indicated when the spinous processes appear off-center (to one side) on an AP lumbar spine projection?
- Excessive lordosis
- Patient rotation (Correct answer)
- Insufficient CR angulation
- Excessive collimation
Correct answer: Patient rotation
On an AP lumbar projection, displacement of the spinous processes to one side of the vertebral midline indicates patient rotation.
ARRT Spine and Pelvis Procedures 4
For the AP projection of the coccyx, the CR is directed: