ARRT Lower Extremity Procedures 4

Question 1

When imaging the entire femur in one projection, the standard AP requires the central ray to be directed to:

Accepted Answer

The mid-femur, with the IR centered accordingly

Answer

The CR is directed to the mid-femur with the IR placed to include both hip and knee joints on a single long image.

Question 2

For the AP projection of the knee, the CR is typically angled how many degrees cephalad in an average patient?

Accepted Answer

5-7 degrees cephalad

Answer

A 5–7 degree cephalad CR angulation parallels the tibial plateau slope, opening the joint space on an average knee AP.

Question 3

For an AP weight-bearing projection of the foot, the patient stands with the foot flat and the CR is directed:

Accepted Answer

Perpendicular to the IR

Answer

For weight-bearing AP foot projections, the CR is perpendicular to the IR to evaluate the arches under physiologic load.

Question 4

Which of the following best describes the position for the lateral projection of the knee?

Accepted Answer

Patient lateral recumbent, affected side down, knee flexed 20-30 degrees

Answer

For a lateral knee, the patient lies with the affected side down, knee flexed 20–30 degrees, and the CR perpendicular to the joint space.

Question 5

For an AP projection of the lower leg (tibia-fibula), which anatomical landmarks should be included on the image?

Accepted Answer

Both the knee and ankle joints

Answer

A complete AP lower leg image must include both the knee and ankle joints to assess the full length of the tibia and fibula.

ARRT - American Registry of Radiologic Technologists Practice Test