Femur 2 (frog leg) Flashcards
What is the clinical indication for the unilateral frog-leg projection?
To assess the hip joint and proximal femur for nontrauma hip situations.
What size image receptor is used for the unilateral frog-leg projection?
24 × 30 cm (10 × 12 inches), crosswise.
What is the kV range for analog systems in this projection?
80 ± 5 kV.
Which tissues should be shielded during the unilateral frog-leg projection?
Radiosensitive tissues outside the region of interest.
How should the patient be positioned for the unilateral frog-leg projection?
With the patient supine, align the affected hip area to the central ray and midline of the table and/or image receptor.
How should the knee and hip be positioned for the affected side?
- Flex the knee and hip,
- The sole of the foot against the inside of the opposite leg, near the knee if possible.
To what angle should the femur be abducted?
45° from vertical for general proximal femur region.
Where should the affected femoral neck be centered?
To the central ray and midline of the image receptor and tabletop distal to ASIS).
Where is the CR directed in the unilateral frog-leg projection?
Perpendicular to the image receptor, directed to the midfemoral neck.
How should collimation be adjusted for this projection?
Collimate on four sides to the anatomy of interest.
What is the optimum femur abduction for demonstrating the femoral neck without foreshortening?
20° to 30° from vertical.
How should respiration be managed during this projection?
Suspend respiration during exposure.
What is the Lauenstein-Hickey method?
- A modified position where the patient rotates onto the affected side until the femur is in contact with the tabletop and parallel to the image receptor,
- foreshortening the neck region but potentially demonstrating the head and acetabulum well if the leg can be sufficiently abducted.
