Week 12 - Femur Imaging Techniques Overview

These flashcards cover key concepts and details regarding femur imaging techniques, including patient positioning, collimation guidelines, and imaging protocols.

What is the central ray (CR) position for the AP femur examination?

Perpendicular to the mid-thigh at the midline.

How should the patient be positioned for an AP femur X-ray?

Supine on the table with no rotation of the pelvis.

What is the angle for leg rotation in the proximal femur X-ray?

15 - 20 degrees medially.

Where should the inferior collimation be placed for a distal femur X-ray?

~2 fingers widths past the patellar apex.

Why should collimation be prioritized over central ray position (CP) in femur imaging?

Collimation emphasizes the area of interest and limits unnecessary exposure.

What is necessary to ensure when imaging a long bone on two separate images?

There must be some overlap (~2” or 2-3 fingers width) between the images.

What should be included in the second image when performing a long bone study?

The other joint with some overlap of the first image.

Which object is used to demonstrate overlap in long bone imaging?

A radiopaque object such as a paperclip.

In lateral femur positioning, what alignment should be maintained?

Hip to ankle in the same plane.

What is the patient position for a distal lateral femur X-ray?

Patient lies on the affected side with the unaffected leg anterior and flexed.

What angle should the knee be flexed during a lateral femur X-ray?

~45 degrees.

What is the central ray position for a lateral proximal femur X-ray?

~5 cm (2.0”) inferior and medially to the ASIS.

What structures should be included in the proximal lateral femur X-ray?

Hip joint and as much femoral shaft as possible.

What indicates good positioning of the proximal lateral femur?

Greater Trochanter (GT) superimposed on femoral neck, lesser trochanter (LT) in profile medially.

What is recommended regarding patient action during X-ray imaging?

Suspend breathing.

What is the importance of checking for no rotation of the pelvis?

To ensure accurate imaging of the femur.

How should collimation be aligned for the AP view of the femur?

Align the top of collimation to the ASIS.

What should be included in the collimation for the distal femur positioning?

The inferior aspect includes a paperclip or indicator of overlap.

What must be ensured between projections when imaging with a paperclip?

The patient's leg must remain still.

When performing a lateral femur view, what do the femoral condyles need to be positioned relative to the table?

Perpendicular to the table.

How should the affected femur be positioned in a proximal lateral view?

Flex knee and rotate towards the affected side until it rests on the table.

What is the recommended positioning for the hip in a proximal lateral femur X-ray?

Hip should be flexed ~60-70 degrees.

How should the patient's torso be supported during the proximal lateral femur positioning?

With sponges under the pelvis and shoulders.

What is the goal when aligning the long axis of the femur to the long axis of the image receptor (IP)?

To ensure proper imaging of the femur.

What is a common practice when imaging the femur in relation to the joints involved?

It's more common to take two images: one for each joint.

In the context of femur imaging, what does 'SI’d' refer to?

Superimposed in the specified direction, indicating correct alignment.

What is the importance of ensuring that both images include the paperclip in long bone studies?

To verify that the entire bone has been imaged.

What condition should not be instructed to patients during femur imaging?

Do not tell the patient to relax; maintain position.

What structures are included in a lateral distal femur view?

Knee joint, distal femur, and as much proximal femur as possible.

How can you secure a radiopaque object like a paperclip during imaging?

Use tape to secure it to the skin edge if necessary.

What is the purpose of ensuring the femoral condyles are not SI’d in the S-I direction during the lateral view?

To confirm they are properly visualized without overlap.