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1513 Ch 8 positioing
RTE 1513 Chp 8 positioning review
Question | Answer |
---|---|
Which two bony landmarks need to be palpated for hip localization | ASIS, Symphysis pubis |
To achieve a true AP position of the proximal femur, the lower limb must be rotated ________. | 15-20* internally |
Method one to locate the femoral head | Find the mid point between the ASIS and symphysis pubis. Neck 2.5 inches and the head is 1.5 inches distal at right angles |
Method two to locate the femoral head | Locate ASIS, Go 1-2 inches medial and 3-4 inches distal to the ASIS |
Which structures on an AP pelvis or hip radiograph indicate whether the proximal head and neck are in position for a true AP projection | Lesser trochanters slightly or not visible |
Which physical sign may indicate that a patient has a hip fracture | external rotation of effected leg |
Which projection should be taken first reviewed by a radiologist before attempting to write the hip into a lateral position (if trauma is suspected) | AP Pelvis |
what is the advantage of using 90kV rather than 80kV range for hip and pelvis studies on younger patients | It reduces the patient dose by 30% |
What is the disadvantage of using 90kV for hip and pelvis studies,especially on older patients with some bone mass loss | Decreases contrast, bones my appear to gray |
Common clinical indication for performing pelvic and hip exam on a pediatric patient | Developmental dsyplasia of hip (DDH) |
Which imaging modality is most sensitive in diagnosing early signs of metastatic carcinoma of the pelvis | Nuclear medicine |
A degenerative joint disease | Osteoarthritis |
Most common fracture in older patients because of high incidence of osteoporosis or avascular necrosis | Proximal hip fracture |
A malignant tumor of the cartilage hip | Chondrosarcoma |
A disease producing extensive calcification of the longitudinal ligament of the spinal column | Ankylosing spondylitis |
A fracture resulting form a severe blow to one side of the pelvis | Pelvic ring fracture |
Malignancy spread to bone via the circulatory and lymphatic systems or direct invasion | Metastatic carcinoma |
Now referred to as developmental dysplasia of the hip | Congenital dislocation |
Which of the following modalities will best demonstrate a possible pelvic ring fracture | CT |
Both joints must be included on an _____ and ____ projection of the femur even if a fracture of the proximal femur is evident | AP, lateral |
Where is the central ray placed for an AP pelvis projection | Midway between ASIS and symphysis pubis |
Which ionization chambers should be activated when using automatic exposure control for an AP pelvis projection | Upper right and left chambers |
Which specific positioning error is present when the left iliac wing is elongated on an AP pelvis radiograph | Rotation in that direction (left) |
Which positioning error is present when the left obturator foramen is more open than the right side on an AP pelvis projection | Rotation in the direction to the right |
Used for patients with traumatic or non-traumatic injuries: Danelius-miller | Traumatic |
Used for patients with traumatic or non-traumatic injuries: Unilateral frog-leg | Non-traumatic |
Used for patients with traumatic or non-traumatic injuries: Modified Cleaves (bilateral frog-leg) | Non-traumatic |
Used for patients with traumatic or non-traumatic injuries: Clements-Nakayama | Traumatic |
Used for patients with traumatic or non-traumatic injuries:Anterior pelvic bones | Traumatic |
which projection is recommended to demonstrate the superoposterior wall of the acetabulum | PA axial oblique |
How many degrees are the femurs abducted (from the vertical plane) for the bilateral frog-leg projection | 40-45* |
where is the central ray placed for a unilateral frog-leg projection | midfemoral neck |
which cassette size should be used for an adult bilateral frog-leg projection | 14x17 crosswise |
Where is the central ray placed for an AP bilateral frog-leg projection | 1 inch superior of the symphysis pubis |
Which central ray angle is required for the outlet projection (Taylor method) for a female patient | 30-40* cephalad |
Which type of pathologic feature is best demonstrated with the Judet method | Acetabular fractures |
How much obliquity of the body is required for the Judet method | 45* |
what type of CR angle is used for a PA axial oblique (Teufel) projection | 12* cephalad |
How is the pelvis (body) positioned for a PA axial oblique (Teufel) projection | PA 35*-40* toward affected side |
The axiolateral (inferosuperior) projection is designed for ______ situations | Trauma |
How is the unaffected leg positioned for the axiolateral hip projection | Flexed and thigh near vertical |
The modified axiolateral requires the CR to be angled _____ posteriorly from horizontal | 15-20* |
Which special projection of the hip demonstrates the anterior and posterior rims of the acetabulum and the ilioischial and iliopubic columns | Posterior oblique pelvis (Judet method) |
Axiolateral (inferosuperior) | Danelius-miller |
Modified axiolateral | Clements-nakayama |
Bilateral or unilateral frog-leg | Modified cleaves |
PA axial oblique for acetabulum | Teufel |
AP axial for pelvic "outlet" bones | Taylor |
Posterior oblique for acetabulum | Judet |
What is the optimal amount of hip abduction applied for the unilateral "frog-leg" protection to demonstrate the femoral neck without distortion | 20-30* from vertical |