Foot & HW 1
Failure to rotate the patient's entire leg and foot when obtaining an AP oblique ankle might result in: Repeat radiograph Poorly positioned leg Poorly demonstrated anatomical structures Well defined ankle mortise
1, 2, and 3
When radiographing the lower leg, what structures should be clearly demonstrated? Ankle joint Knee joint Tarso metatarsal joint Bony trabeculae
1, 2, and 4
When taking an AP oblique of the toes how should the foot be rotated?
1-2 toes medially, 4-5 toes laterally, third ormiddle toe doesn't matter
CR for AP axial
10 degrees towards heel entering base at 3rd metatarsal
Film size for AP, AP axial, medial oblique foot
10x12 or 11x14 LW
How many phalanges are in the foot?
14
Direction of CR for AP toes when joint spaces need to be seen
15 degrees posteriorly through 3rd MCP or elevate the foot on a 15 degree foam wedge with no angulation on CR
The joint between the proximal and distal phalanges
1st interphalangeal joint
Proximally the metatarsals articulate with
1st, 2nd, 3rd cuneiform and cuboid
How many bones are in the foot and ankle?
26
In the AP oblique projection with medial rotation of the foot, the plantar surface surface of the foot should form an angle of____________ with the cassette.
30 degrees
In order to BEST demonstrate the distal ends of the tibia and fibula, how much should the leg and foot be rotated when performing the AP oblique ankle with medial rotation?
45 degrees
When radiographing a foot the central ray is directed 10 degrees posterior (towards the os calcis) and enters the base of the 3rd metatarsal. What image is obtained?
AP Axial of the foot
On the calcaneus superiorly there are 3 _______, called anterior, middle, and posterior that join with the talus.
Articular facets
Alternative term for talus
Astragalus
Where the Achilles' tendon attaches
Calcaneal posterior tuberosity
The largest of the tarsals
Calcaneous
Heel bone
Calcaneus
Which of the following bones articulate with the talus inferiorly?
Calcaneus
When is the lateromedial projection of the ankle recommended? Erect for weight-bearing ankle Cross-table for trauma For patient comfort It is not recommended
Cross-table for trauma
Midfoot
Cuneiforms, navicular, and cuboid
In order to best demonstrate the joint spaces when radiographing toes in the AP projection, how should the CR be directed and where should it enter?
Direct the CR 15 degrees posteriorly entering the 3rd MTP with the toes resting directly on the cassette Direct the CR perpendicular entering the 3rd MTP if the toes are placed on a 15 degree angle sponge.
(T/F)When demonstrating the 1st and 2nd toes in the oblique position, the foot should be obliqued laterally.
False
Purpose of AP foot
Foreign body
Cuneiforms
Identified medial to lateral; anterior to navicular and posterior to 1st, 2nd, 3rd metatarsals
Foot AP oblique with medial rotation position structures demo'd
Interspaces (between cuboid & calcaneus/between cuboid & 4th and 5th metatarsals/ between talus & navicular/ between cuboid & lateral cuneiform) Tuberosity of the 5th metatarsal Cuboid shown in profile Sinus tarsi well shown
The Method used to demonstrate congenital club foot is known as:
Kite
When performing the mediolateral projection of the foot, which side of the foot will the technologist instruct the patient to place on the IR?
Lateral side
Navilicular
Lies on medial aspect/ between talus posteriorly/ between cuneiforms anteriorly
Which projections is most commonly used in clinics to obtain a lateral image of the foot?
Mediolateral
Structures demonstrated for AP and AP axial
Metatarsals, phalanges, and tarsals anteriorly to talus
eval criteria for AP oblique with medial rotation
No superimposition of bases 3-5th metatarsals Bases of the 1st and 2nd metatarsals superimposed Bases of 4th and 5th clearly demonstrated Sinus tarsi & tuberosity of 5th metatarsal
Alternative term for calcaneus
Os calcis
Foot AP eval criteria
Overlap of 2-5 metatarsal bases, no rotation
Foot AP axial eval criteria
Overlap of 2-5 metatarsal bases, no rotation, open joint spaces
Are the IP joint spaces better seen on AP or PA toes and why?
PA, less beam divergence
CR for all foot positions EXCEPT LATERAL:
Perpendicular to IR entering base of 3rd metatarsal
When radiographing the foot in the AP projection for possible localization of a foreign body, the CR should be directed:
Perpendicular, entering the base of the 3rd metatarsal
How should the CR be directed and where should it enter for the AP oblique projection with medial rotation of a foot?
Perpendicular, to the base of the 3rd metatarsal
Forefoot
Phalanges and metatarsals
Which of the following would NOT be demonstrated in the axial plantodorsal projection of the calcaneus? Answers: Subtalar joint Cuboid calcaneal joint space Sustaculum tali Sinus tarsi
Sustaculum tali
Shelf like process on the medial body of the calcaneus
Sustentaculum tali
The shelf-like overhang structure on the medial aspect of the calcaneus is the ___________.
Sustentaculum tali
Congenital clubfoot is also known as ________ .
Talipes equinovarus
2nd largest and most superior tarsal bone
Talus
Articulates with the tibia, fibula, calcaneous, and navicular
Talus
The ankle mortise is formed by:
Talus Fibula Tibia
Hindfoot
Talus and calcaneus
When performing an AP oblique ankle, the technologist rotates the patients entire leg and foot together 15-20 degrees. What will be the result of this image?
The Ankle Mortise joint will be best demonstrated
The CR is directed 40 degrees cephalic and enters at the base of the 3rd metatarsal, what image is produced?
The axial plantodorsal projection of the calcaneus
f you were requested to do an AP oblique projection of a foot in lateral rotation, which of the following structures would be demonstrated?
The interspaces between the medial and intermediate cuneiforms AND the interspaces between the 1st and 2nd metatarsals
While performing the AP oblique foot with medial rotation the technologist rotates the foot so the plantar surface forms a 45 degree angle to the plane of the IR. How will this visually effect the image?
The lateral cuneiform will be superimposed over the other cuneiforms.
What type of joint is distal between the proximal row of phalanges and metatarsals
The metatarsophalangeal joints
What type of joint is proximal between the metatarsals and tarsals
The tarsometatarsal joints (TMT)
The medial malleolus is located on the:
Tibia
Which bones form the ankle
Tibia and talus forming the talotibial joint
What is the purpose of dorsiflexing the foot when performing the lateral ankle?
To prevent lateral rotation of the ankle
(T/F) The routine projections for a lower leg consist of AP and Lateral
True
(T/F) When demonstrating the 4th and 5th toes in the oblique position ,the foot should be obliqued medially.
True
the lateromedial demonstates
a true lateral of the foot
eval criteria AP oblique foot with lateral rotation
all necessary anatomy may include portions of talus & calcaneus proper rotation (1st and 2nd bases free from superimposition, minimal superimposition between medial and intermediate cuneiforms, navicular seen with less foreshortening than medial rotation)
CR for calcaneus axial plantodorsal
angled 40 degrees cephalad or to the long axis of the foot; entering at base of 3rd metatarsal
structures demo'd lateral calcaneus
ankle joint and calcaneus in profile
structures demo'd in mediolateral kite method
anterior talar subluxation and degree of plantar flexion
structures demonstrated in axial plantodorsal
axial projection of calcaneus (os calcis); including calcaneal tuberosity and sustentaculum tali
where is the sinus tarsi located?
between the calcaneous and talus
eval criteria for lateral calcaneus
calcaneal tuberosity, sustenaculum tali, sinus tarsi, ankle joint
eval criteria for axial plantodorsal
calcaneus and subtalar joint, calcaneal tuberosity, trochlear process, lateral process, sustentaculum tali, talocalcaneal joint, cuboid calcaneal joint
structures demo'd for lateral mediolateral foot
entire foot in profile, distal ends of tibia & fibula, ankle joint
purpose of axial plantodorsal?
for demonstration of fxs and spurs
foot AP oblique with lateral rotation structures demo'd
interspaces between 1st and 2nd metatarsals, 1st and 2nd cuneiforms Navicular clearly demonstrated
why is the lateromedial not done routinely
it's uncomfortable for the patient
part position of lateral calcaneus
lie on affected size, place calcaneus on IR and doriflex foot
which side of the patient is placed on the IR for lateromedial
medial side
what type of projection is the kite method?
mediolateral
eval criteria for lateral mediolateral foot
metatarsals nearly superimposed, sustentaculum tali, sinus tarsi, fibula overlapping posterior part of tibia, distal tibia & fibula, talotibial joint
position of part and patient for mediolateral kite method
patient: lateral on side, flex uppermost limb bend knee and draw it forward part: place foam under knee (on leg of foot being imaged) to prevent angling of foot and ensure lateral position
CR lateral calcaneus
perpendicular to mid calcaneus (os calcis)
CR for kite method
perpendicular to midtarsal area
part position for mediolateral foot
place injured foot on lateral side, dorsiflex foot (foot should be 90 degrees to the leg), plantar surface parallel to long axis of IR
what is the function of the longitudinal arch of the foot?
shock absorber, distributes weight, and permits smooth walking
which joint space is not always open in the toe oblique?
the 1st MCP joint
which foot position shows the cuboid in profile?
the AP oblique projection with medial rotation
hallux valgus
the angulation of the 1st toe towards the other toes