Criteria for assessing image quality
Sharp image demonstrating the soft tissue margins, bony cortex and trabeculae of tibia, fibula, femur and patella, with sufficient penetration to visualise the bony trabeculae and cortical outline of the patella over the femur. Demonstration of the knee joint space in contrast to bony areas.
The patella appears medially in relation to the femur and the proximal tibiofibular joint is demonstrated. The joint space may appear narrowed or obscured, unilaterally or bilaterally. Part, or all, of the tibial plateau does not appear to be seen in profile | The leg is excessively internally rotated; ensure the tibial condyles are equidistant from the IR and the patella is centralised. However, take care to note whether the patient has a naturally medially positioned patella or knock knees before attempting repeat projection. If the tibiofibular joint appears to be demonstrated correctly, and joint space shown clear, then it is likely that the patient’s patella does not naturally lie centrally positioned; an example of this is shown in Figure 9.1C |
The patella is projected laterally in relation to the femur and the proximal tibiofibular joint is obscured by the tibia. The joint space may appear narrowed or obscured, unilaterally or bilaterally. Part or all of the tibial plateau does not appear to be seen in profile | There is excessive external rotation of the leg. Patellae are less likely to naturally lie on the more lateral aspect over the femur than medially, as above, but note should still be made to check if this is the case |
There is no bony detail of the patella demonstrated – pale image of patella but femur may show trabecular detail outside the periphery of the patella | The radiograph is under-penetrated; increase kVp |
The neck of the femur projects anteriorly at an angle of
In order to accurately position the patient for hip radiographs, one must localize two bony points on the pelvis called
superior margin of the symphysis, anterior superior iliac spine
The iliac articulates with the sacrum posteriorly at the
how many degrees should the feet and lower limbs be inter ally rotated for an AP pelvis radiograph?
the CR for an AP pelvis is directed perpendicular to the center of the IR. The CR entrance pt. will be about
2 inches superior to the pubic symphysis
which of the following will be shown "in profile" if the lower limbs are in correct position for an AP pelvis
Which method will demonstrate the femoral necks in the AP oblique projection?
for the Ap oblique femoral necks (modified cleaves method), the CR is directed
How much should the thighs be abducted for the AP oblique projection of the femoral necks (modified Cleaves method)
Where does the CR enter the patient for an AP hip?
2.5" distal on a line drawn perp to the midpt of a line btw ASIS & pubic symphysis
How many degrees is the lower limb and foot rotated internally for an AP hip?
What is the CR angle for an AP projection of the hip?
Which method will demonstrate the hip in a lateral projection
Unless contraindicated, the lower limb and leg should be internally rotated for an axiolateral projection of the hip (Danelius-Miller). How many degrees of rotation are required?
What is the respiration phase for the AP projection of the pelvis?
The strongest bone in the body
where is the IR centered for an AP pelvis
midway between the ASIS and pubic symphysis
How much is the knee flexed for a lateral projection of the patella?
The knee is in the correct position for a lateral projection of the patella if the
epicondyles are superimposed, patella is perpendicular to the IR
What is the CR angle for a lateral projection of the patella?
Where does the CR enter the knee for a lateral projection of the patella?
through the patellofemoral joint space
what is the CR angle for an Ap projection of the femur?
how many degrees should the limb be internally rotated for an AP projection of the femur?
How far should the IR/collimated field extend below the knee for a lateral projection of the femur?
If a lateral projection of the femur will include the hip joint, where should the top of the IR/collimated field be placed?
anterior superior iliac spine (ASIS)
How far should the patient be rolled posteriorly from the lateral position, for a lateral projection of the hip that will include the proximal femur?
Posteriorly, the femoral condyles are separated by a deep depression called the
Which devices are necessary to perform an axiolateral projection of the hip (Danelius-Miller)?
sandbags, leg support device, vertical IR holder
Which is important and frequently used radiographic positioning reference point?
anterior superior iliac spine
How far apart should the heel she placed in order to internally rotate the lower limbs for an AP pelvis
which best describes the female pelvis
the angle of the SI joints is ___ degrees relative to the midsaggital plane