Week 9 - AP Tibia/Fibula Imaging Techniques

These flashcards summarize key imaging techniques and considerations for AP and lateral tibia/fibula radiographs.

What is the central ray (CR) direction for imaging the AP tibia/fibula?

Perpendicular.

Where is the central point (CP) located for the AP tibia/fibula?

Midpoint of lower leg at the midline.

What structures should be included in an AP tibia/fibula radiograph?

Complete tibia/fibula, distal femoral condyles, proximal talus.

What is the required collimation for the AP tibia/fibula?

Open collimation 1 inch proximal to femoral condyles and 1 inch distal to malleoli.

What is the main goal for the proximal fibula during an AP tibia/fibula image?

¼ of fibular head should be superimposed (SI) on tibia.

What is the main goal for the distal fibula during an AP tibia/fibula image?

½ of fibula should be SI’d by tibia; medial mortise should be open.

What is the positioning of the patient for an AP tibia/fibula?

Patient’s leg extended, lateral aspect of leg aligned with lateral aspect of image receptor (IR).

What is a critical step for obtaining two images of a long tibia/fibula?

Ensure there is overlap of about 2 inches between the images.

What should you do with the patient's foot during the AP tibia/fibula imaging?

Dorsiflex the foot.

How should the foot be positioned for an AP tibia/fibula?

The foot should be perpendicular to the IR.

How do you ensure a true AP of the tibia/fibula?

Internally rotate the leg very slightly.

When performing a lateral view, where should the radiopaque object be placed?

Change the object to the anterior or posterior surface.

Why is it important to include the lateral malleolus in the image?

It is the most distal aspect of the tibia/fibula.

What should be done if the region of interest (ROI) won't fit on the IR?

Increase the source-to-image distance (SID) to decrease magnification and adjust the technique accordingly.

What is the positioning for the lateral tibia/fibula?

Patient lying on the affected side with the knee slightly flexed.

How should the femoral condyles be aligned for a lateral tibia/fibula?

They should be perpendicular to the table.

What should be palpated to ensure proper positioning of the knee?

The sides of the femoral condyles.

What is the importance of having mid knee and mid ankle in the same plane?

It ensures accurate alignment and positioning for the radiograph.

What can be used under the patient's ankle for better angling during a lateral view?

A sponge.

Why are femoral condyles more reliable than the patella in alignment?

The patella can shift laterally with age or due to arthropathy.

What does SI mean in the context of tibia/fibula imaging?

Superimposition.

How much of the fibula should be in the posterior half of the tibia during a lateral view?

The distal fibula should be in the posterior half of the tibia.

What is essential for obtaining accurate images of both the knee and ankle joints?

Ensuring that the joints closest to the injury are included in the images.

What should you ensure if you take two separate images of a long bone?

Demonstrate some overlap to prove the entire bone has been imaged.

In the case of injury, how should the imaging be adjusted?

Focus on the joint nearest to the injury and include overlap when performing joint imaging.

Why is it important for the patient's leg to remain still between projections?

To avoid movement artifacts and ensure image clarity.

What structures are included in a lateral tibia/fibula radiograph?

Entire tibia/fibula, distal femoral condyles, malleoli, proximal talus.