Exam 3: Toes, Foot, Ankle, Calcaneus, Tib/Fib, Knee, & Patella

Label 6

third metatarsal, right foot

AP Oblique foot medial rotation criteria

• Tuberosity of the fifth metatarsal

• = amount of space between shafts of 2nd-5th metatarsals

• Closed joint space b/w medial and intermediate cuneiforms

• Open joint spaces around cuboid and the sinus tars

Degree of rotation of the toes for an AP oblique medial rotation projection? 

30-45 degrees

Degree of tube angulation for an AP axial projection of the foot

10 degrees posterior

label 18

lateral cuneiform

Centering point for plantodorsal projection of the calcaneus

entering plantar surface near the base of the third metatarsal

Which tarsal bone articulates with the distal tibia and fibula to form the mortise joint?

talus

Ankle positioning in this image

right leg/foot obliqued medially 45 degrees

AP oblique ankle rotation

15-20 degree medial rotation

An AP oblique ankle rotation with 15-20 degree medial rotation will place the intermalleolar plane of the ankle ______ with the plane of the IR.

parallel

The AP ankle stress view is useful in verifying: 

ligamentous tears

Degree of tube angulation for an AP axial projection of the toes to best demonstrate the joint spaces?

15 degrees CR angulation

How much foot rotation is needed for an AP oblique projection of the foot with medial rotation?

30 degrees medial rotation

Label 1

Talus

CR for an AP oblique projection, medial rotation of the toes (to include all toes)? 

 

perpendicular to IR, entering the 3rd MTP joint

What tube angle will reduce foreshortening in the phalanges and metatarsals of the foot?

angling tube 10 degrees towards the heel

How was the central ray set up to produce this image?

40 degree angle towards the heel

What projection and anatomy is this?

Calcaneus axial (plantodorsal), Harris view

What projection and anatomy is this?

AP oblique ankle

What positioning is used to achieve this image?

the lower extremity rotated medially 45 degrees

the lower extremity rotated medially 45 degrees best demonstrates the _____

 

Distal tibiofibular joint open

What projection and anatomy is this?

AP oblique projection

This AP oblique projection of the right ankle was performed with what rotation of the lower leg?

 

15-20 degrees medial

The standard projection for a lateral ankle is the: 

mediolateral

Where should the CR be placed for the routine lateral calcaneus? 

 

1" inferior to medial malleolus

Each foot consists of ________ bones.

26

What portion of the 5th metatarsal is frequently fractured? (Jones Fracture) 

proximal/base

Gout

condition that appears radiographically as uric acid and deposits in joint space (leading to destruction of joint space)

Centering point for an AP axial foot projection?

base of 3rd MT (metatarsal) 

degree and direction of CR angle for the AP axial foot 

 10 degrees posterior ( towards the heel)

What is the direction of rotation for the AP Oblique foot projection? 

medial/internal rotation

Which is the preferred lateral projection of the foot?

mediolateral

SID for a lateral weight-bearing foot projections?

40'“

benefit of doing an AP axial toe projection instead of an AP toe projection?

opens up IP joint spaces and reduces foreshortening

What is the (1) degree of tube angulation, (2) the direction of the central ray, and (3) centering point for an AP axial toe projection?

15 degrees posteriorly, centered to the MTP joint

Name tarsal bones in the midfoot that are less superimposed when doing an AP oblique medial rotation projection of the foot versus an AP foot

navicular, lateral cuneiform, cuboid

With which projection are the cuboid and its articulations best demonstrated

 

AP oblique foot in medial rotation position

What special projection of the lower extremity is demonstrated?

Tangential projection (Holly method), sesamoid bones

What part of the foot should be perpendicular to the IR on a lateral projection of the foot?

 

plantar surface

Centering point for each toe 2-5 in a lateral projection?

 

perpendicular to PIP of interest

Which joint spaces are demonstrated open on the AP axial projection of the toes?

IP joints and MTP joints

To evaluate the sesamoid bones in the toes, the tangential sesamoids projection requires the CR to be:

 

perpendicular to IR, directed to posterior aspect of 1st MTP joint

What type of leg/foot rotation is done routinely with AP oblique ankles? (medial rotation or lateral rotation) 

medial rotation

How much rotation is required on the AP oblique Mortise projection of the ankle?

15-20 degrees medial rotation

How should the patient's foot & ankle be positioned for an axial projection of the calcaneus?

dorsiflexed

CR angle for an axial projection of the calcaneus?

40 degrees, towards the heel

Under what circumstances might you perform a (less common) lateromedial ankle projection?

trauma, patent can't move from supine, image will be a crosstable projection

centering point for an axial projection of the calcaneus?

base of third metatarsal

Which projection of the ankle will place the intermalleolar plane of the ankle parallel with the plane of the IR?

AP oblique mortise (15-20 degrees medial rotation)

When looking at images, what is one way you can tell the mediolateral lateral projections of the calcaneus vs the ankle?

Centering: The calcaneus will be 1" distal to the medial malleolus whereas the ankle centering will be on the medial malleolus. 

Collimation: The calcaneus should be more closely collimated.

How do you get the mortise joint "open" on an image?

medially rotate the foot/leg 15-20 degrees

What type of fracture is commonly seen at the base of the 5th metatarsal?

Jones fracture

What 2 tarsal bones make up the hindfoot?

talus and calcaneus

What joint should be well visualized on a properly positioned axial calcaneus projection?

talocalcaneal (subtalar) joint

CR for a lateral projection of the calcaneus?

1" distal to the medial malleolus

For the mortise joint to be demonstrated, the lower limb must be positioned in

 

15-20 degree medial oblique

Which clothing items might cause an artifact during imaging of the lower extremity?

socks, shoes, jeans, jewlery

Which name is given to a fracture at the fifth metatarsal base?

Jones Fracture

Which tarsal bone articulates with the distal tibia and fibula to form the mortise joint?

Talus

Which positioning maneuver was required to produce this image?

Dorsiflexion to place plantar surface perpendicular to IR

What projection and anatomy is this

plantodorsal axial calcaneus projection

What was the CR orientation for this projection?

40 degrees toward the heel

Which malleolus is more posterior?

lateral

Which projection will open the tibiofibular joint space?

AP oblique 45 degree internal rotation

SID for the AP axial calcaneus? 

 

40"

A grid should always be used for AP and Lateral projections of the ankle

false

The CR is directed ____ to the IR for the AP oblique Mortise ankle projection

perpendicular

The joint space highlighted in the image below is the: 

 

talofibular joint

The joint space highlighted in the image below is the: 

 

tibiotalar joint

The joint space highlighted in the image below is the: 

 

mortise joint

The joint space highlighted in the image below is the: 

distal tibiofibular joint

CR angle when radiographing the knee joint space in the AP projection on  patient whose ASIS – tabletop measurement distance is 23.5 cm ?

perpendicular

This is a ____________ projection of the _______________

AP; left knee

Which of the following structures serves as a shock absorber within the knee joint?

 

Meniscus

3

fibular head

1

medial epicondyle

2

patella

4

intercondylar tubercles

7

 

right lateral tibial plateau

8

right femoral intercondylar fossa

9

right medial femoral condyle

Why is a long SID recommended for the Merchant’s Method?

 

to decrease magnification

1

Patella

3

lateral femoral condyle

4

medial femoral condyle

5

Fibula

How much will you oblique the patient knee for an AP oblique with medial or lateral rotation?

 

45 degrees

What anatomy is indicated by the white line?

 

Medial tibial condyle

For a lateral projection of the knee, the plane through the femoral epicondyles is positioned in what orientation to the plane of the IR?

perpendicular

What of the following options will best place the knee in true AP position?

 

rotate lower limb internally 3-5 degrees

What projection best reveals narrowing of the joint space at the knee (tibiofemoral) joint?

 

AP weight-bearing method of the knees

What projection and position are demonstrated?

AP oblique projection of the knee, lateral rotation position

anatomy & positioning for a Camp-Coventry method image?

PA axial projection of the intercondylar fossa

what method is this

camp-coventry

1

 

left medial femoral epicondyle

The PA projection of the patella provides improved spatial resolution over the AP projection because:

it uses a smaller OID on the PA projection

Which statement best describes the correct central ray for this projection?

angle of 5-7 degrees cepahlic

Describe the location of the apex and base on the patella.

the apex is pointed inferior and base is the superior border of the patella

Must gonadal shielding always be used for all pelvis and hip images?

False. Shielding is used only when it does not compromise the exam objectives.

How are the lower limbs positioned for an AP pelvis?

Medially rotate 15–20 degrees.