CAMRT Radiography Practice Exam

In the AP projection of the knee, what is true?

1. Femoral condyles are superimposed

2. CR is directed 1.5 cm distal to the patellar apex

3. Patella is visualized through the femur

4. All of the above

The correct answer is: CR is directed 1.5 cm distal to the patellar apex

In the AP projection of the knee, the central ray (CR) is indeed directed 1.5 cm distal to the patellar apex. This positioning ensures that the area of interest, specifically the knee joint space, is optimally visualized. Accurate beam placement is critical in radiography to achieve the best possible image quality and to avoid misinterpretation of the anatomy. While the other statements may seem plausible, they do not contain the key details relevant to the AP projection of the knee. For instance, in this projection, while the femoral condyles should ideally demonstrate some degree of superimposition, the typical positioning does not guarantee complete superimposition due to individual anatomy and positioning variances. Additionally, the patella is not typically visualized through the femur in an AP view; instead, it is located in front of the femur, providing a different radiographic appearance. Therefore, the correct understanding aligns closely with the proper technique for CR placement in the AP projection of the knee.