Purpose
Observe the femur from the hip joint to the knee joint in anterior view.
Prior confirmation
Confirm the examination purpose and the affected area. If the proximal femur is of interest, an hip-joint AP view is suitable.
Determine the presence of fractures. In case of a fracture, do not internally rotate the affected side.
For adults, project the knee joint and femoral head onto the diagonal of 17×14 inch the cassette size. If it doesn’t fit within 17×14 inch the cassette size, decide whether to prioritize the hip joint or knee joint for imaging, or split it into two images.
Remove any obstructing objects.
Positioning
Supine position.
Ensure that there is no tilt in the pelvis by aligning the left and right anterior superior iliac spines and the cassette equidistantly.
Internally rotate the lower limb (knee) until the patella of the examined side is positioned at the center of the femur (approximately 5°).
Abduct the lower limb of the non-examined side and move it out of the field of view.
Align the knee joint to the corner of the irradiation field that matches the 17×14 inch cassette size. Keep in mind that the femoral head is positioned 45° inward and upward from the greater trochanter as you adjust the angle of the irradiation field. Finally, place the cassette to match the irradiation field.
Cover any unnecessary exposure areas with a lead plate.
Place the RL marker.
CR, distance, field size
CR : Perpendicular beam directed toward the center of the femur.
Distance : 100 cm.
Field size : Include the hip joint to the knee joint, and narrow it down to the skin surface. There is also a method to demonstrate anteroposterior positioning by including the obturator foramen.
Exposure condition
70kV / 10mAs
Grid ( + )
Image, check-point
Normal (Radiopaedia)
Ensure that the area from the hip joint to the knee joint is included.
The patella should be positioned at the center of the femur, both left and right.
The medial and lateral condyles of the femur should be symmetrically projected.
The head of the fibula should overlap with 1/2 to 1/3 of the tibia.
The cortex and medullary canal of the femoral shaft should be clearly visible.
Adequate tolerance to observe soft tissue.
Ensure the presence of the RL marker.
There should be no motion blur.
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