Week 12 - Femur Imaging Techniques

A collection of flashcards covering key concepts, terms, and positioning details for femur imaging techniques.

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

Perpendicular to the midthigh at the midline, varying depending on the image being taken and the height of the patient.

How should the patient be positioned for an AP femur image?

Patient should be supine on the table with no rotation of the pelvis.

Which way should the leg be rotated for a true AP of the proximal femur?

15-20 degrees medially.

Where should the superior collimation be placed for a proximal femur image?

At the level of ASIS.

Where should the inferior collimation be placed for a distal femur image?

Approximately 2 fingers widths past the apex of the patella.

What should be included when imaging the femur?

Both joints must be included, with more common practice doing two images rather than one.

When imaging long bones on two separate images, what is necessary to demonstrate?

Some overlap of approximately 2 inches or 2-3 fingers width.

What is the purpose of placing a radiopaque object (like a paperclip) during imaging?

To prove the entire bone has been imaged and assist in ensuring proper overlap.

What position should the patient be in for a lateral distal femur imaging?

Patient lying on the affected side.

How should the unaffected leg be positioned during a lateral distal femur imaging?

Positioned anterior and flexed on the table for support.

What are the structures included in a lateral distal femur image?

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

What is the required positioning for the femoral condyles during lateral femur imaging?

They should be positioned to be superimposed in the A-P direction.

What is the central ray (CR) location for a lateral proximal femur image?

Approximately 5 cm (2 inches) inferior and medially to ASIS.

What should be included in the image of the lateral proximal femur?

The hip joint and as much femoral shaft as possible.

What is the knee positioning for a lateral femur image?

Lateral and flexed at ~45 degrees.

How should you manage the position of the patient's femur for a lateral proximal femur image?

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

What indicates good positioning of the femur in a lateral view?

Greater Trochanter (GT) superimposed on Femoral neck, Lesser Trochanter (LT) in profile medially, and Femoral neck perpendicular to the image receptor.

What should you ensure concerning the femur and the table?

The femur should be parallel to the table.

Why should breathing be suspended during femur imaging?

To reduce motion artifact due to proximity to the abdomen and ensure a clear image.

What two positions can the paperclip be placed in for lateral images?

On the lateral margin of the collimation for AP images and on the anterior surface for lateral images.

What should be avoided during the positioning of the patient?

Instructing the patient to relax, as they must maintain position.

In imaging protocols, how is the planning for overlapping images done?

The joint closest to the injury is included first, then the opposing joint for completion.

Where should the superior collimation be aligned for proper imaging?

Aligned with the ASIS.

How can sponges assist during femur imaging?

Used for support to ensure the hip and knee are in the same plane.

What is the significance of including a paperclip in the overlap of images?

It is used to ensure both images include the paperclip, confirming proper overlap.

What positioning technique helps with ensuring the hip to ankle is in the same plane?

Using sponges as required.

What should be included in the inferior collimation for a lateral femur image?

Collimate approximately 2 fingers widths distal to the patella apex.