Lower Extremity Flashcards
For the mediolateral lateral projection of the calcaneus, where is the central ray directed?
1 inch distal to the medial malleolus
For the axial plantodorsal projection of the calcaneus, what angle is adjusted on the x-ray tube?
40 degrees
In a lateral projection of the third toe, where should the central ray be directed?
third proximal interphalangeal joint
In the AP oblique projection of the foot, what angle should the sole of the foot be rotated to?
30 degrees
In the axial plantodorsal projection of the calcaneus, where does the central ray enter?
the base of the 3rd metatarsal
For an AP projection of the foot, where is the central ray directed?
base of the 3rd metatarsal
What does a frontal projection of the ankle evaluate when the foot is in an inverted (pulled medially) position?
(Ankle stress view)
lateral collateral ligament
In an AP projection of the toes, how many degrees should the central ray be directed to best demonstrate the joint spaces?
15 degrees cephalic
What are the tangential projections (Lewis and Holly) of the foot used for?
evaluation of sesamoid bones
What specific part of the foot is evaluated with weight bearing lateral projections?
longitudinal arch
In the anteroposterior projection of the foot, how should the central ray be directed to demonstrate the joint spaces?
10 degrees posteriorly
What is the degree of central ray angulation for the axial plantodorsal projection of the os calcis?
40 degrees
What is another term for an AP projection of the foot?
dorsoplantar
What is the SID used for an AP axial projection weight bearing method of the foot?
48 inches
For a lateromedial projection of the ankle, where is the CR directed?
½ inch superior to the lateral malleolus
How do you check for rotation on an AP axial projection of the calcaneus?
the first or fifth metatarsals are not projected to the sides of the foot
What are the two bones of the lower leg and their positions?
- tibia - medial side
- fibula - lateral side
Where is the CR directed for the medial oblique (lateral rotation) projection of the foot?
base of the 3rd metatarsal
Where is the CR directed for an AP projection of the ankle?
at the ankle joint midway between the malleoli
How many degrees is the lower leg rotated for an oblique projection of the tibia and fibula?
45 degrees
How many degrees is the ankle obliqued to show the tibiofibular articulation?
45 degrees
How many degrees is the ankle obliqued to best demonstrate the ankle mortise joint?
15-20 degrees
How is your patient positioned for the Lewis method of the sesamoid bones?
prone
How is the central ray directed for an AP projection of the lower leg?
perpendicular
For the Holly method of the sesamoid bones, the plantar surface of the foot should form an angle of how many degrees with the plane of the IR?
75 degrees
Which projection of the foot will best demonstrate the longitudinal arch?
lateral weight-bearing
In which projection of the foot are the sinus tarsi, cuboid, and tuberosity of the fifth metatarsal best demonstrated?
medial oblique foot
What are the purposes of AP stress studies of the ankle?
1) to demonstrate fractures of the distal tibia and fibula
2) following inversion and eversion injuries
3) to demonstrate a ligament tear
2 and 3 only
What is the angle used on the CR for the first and second projection in the weight bearing composite method AP axial projection of the foot?
1st - 15 degrees, 2nd - 25 degrees
Which of the two projections of the weight bearing composite method requires an increase in exposure factors?
The second image (coming in from the back of the patient)
What is the routinely done lateral projection of the lower leg?
Mediolateral
Where is the central ray directed for an AP projection of the lower leg?
To the center of the leg
For an AP projection of the knee, where is the CR directed?
½” inferior to the apex of the patella
In the AP projection of the knee, what is the central ray angle if the patient measures 22 cm from ASIS to Table Top?
0 degrees (perpendicular)
For the lateral projection of the knee, how many degrees should the knee be flexed?
20-30
How is the CR directed for the lateral projection of the knee?
5-7 degrees cephalad
Where does the CR enter for the lateral projection of the knee?
1” inferior to the medial epicondyle
