To BEST visualize the knee joint in a lateral projection, how should the x-ray tube be angled?

To BEST visualize the knee joint in a lateral projection, how should the x-ray tube be angled?

• A. Caudad 10-15
• B. Cephalad 10-15
• C. Caudad 5-10
• D. Cephalad 5-10

Answer: (D)

A small cephalad tilt of the x-ray beam helps align the beam with the knee’s joint plane in the lateral view. About 5–10 degrees cephalad places the central ray perpendicular to the knee joint line as the knee is positioned on its side with about 20–30 degrees of flexion. This opens the joint space and keeps the femoral and tibial condyles superimposed for a true lateral image, improving visualization of the joint. Tilting caudally would move the beam away from the joint line and can obscure the joint details or distort the view.

A small cephalad tilt of the x-ray beam helps align the beam with the knee’s joint plane in the lateral view. About 5–10 degrees cephalad places the central ray perpendicular to the knee joint line as the knee is positioned on its side with about 20–30 degrees of flexion. This opens the joint space and keeps the femoral and tibial condyles superimposed for a true lateral image, improving visualization of the joint. Tilting caudally would move the beam away from the joint line and can obscure the joint details or distort the view.