Radiologic Eval of Foot and Ankle

Question 1

List radiologic views of the foot and ankle taken during a routine radiologic exam

Answer 1

1. Ankle
   
   1. AP
   2. AP Oblique (mortise)
   3. Lateral
   4. Stress views
2. Foot
   
   1. AP
   2. Lateral
   3. Oblique

Question 2

list the 2 different stress views of the ankle

Answer 2

1. AP Inversion and Eversion Stress View
2. Anterior Talar Drawer Stress View

Question 3

________ are typically the first study for suspected bony and soft tissue abnormalities of the foot and ankle

Answer 3

X-rays

helps with diagnosis and directs further imaging

Question 4

list/describe general indications for when other imaging techniques are used at the foot and ankle

Answer 4

1. Bone scan used for screening the skeleton for:
   
   1. metastases
   2. local CRPS
   3. potentially local radiographically occult fractures
2. CT commonly used for defining:
   
   1. complex fractures
   2. osteochondral lesions
   3. tarsal coalition
3. MRI commonly used for:
   
   1. defining soft tissue injuries
   2. stress fractures
4. USI possibly for superficial soft tissue abnormalities (e.g. tendon disorders)

Question 5

list general indications for CT of the foot and ankle

Answer 5

1. Severe trauma
2. fracture/dislocation/alignment/displacement
3. loose bodies within the joint
4. osteochondral lesions
5. tarsal coalition
6. pre-op planning
7. health conditions typically viewed with MRI, if MRI is contraindicated

Question 6

what is tarsal coalition?

Answer 6

an abnormal connection between two or more bones in the back of the foot

this can cause pain, stiffness and impact ADLs

Question 7

list general indications for MRI of the foot and ankle

Answer 7

1. tendon disorders → Achilles, posterior tibial, fibularis
2. ligament abnormalities: M/L ankle, syndesmotic
3. impingement syndromes
4. Osteochondral lesions
5. articular cartilage abnormalities
6. neurologic conditions
7. loose bodies
8. plantar fasiopathy
9. synovial disorders
10. marrow abnormaltieis
11. neoplasm
12. infection
13. congenital/developmental conditions
14. staging diseases
15. specific clinical scenarios

Question 8

what diseases at the foot and ankle may MRI be used to stage?

Answer 8

1. inflammatory arthropathies
2. bone/soft tissue tumors
3. fractures/stress fractures

Question 9

list specific clinical scenarios of the foot and ankle that MRI is indicated for

Answer 9

1. prolonged, unexplained ankle/foot pain
2. acute trauma
3. ankle and hindfoot injury among dancers and other athletes
4. ankle/subtalar instability
5. nerve entrapment
6. atrophy/mass
7. limited/painful ROM
8. planned arthroscopy
9. residual/new symptoms following surgery

Question 10

List the Ottawa Ankle Rules for an ankle x-ray series

Answer 10

1. bone tenderness at posterior edge/tip of lateral malleolus
2. bone tenderness at posterior edge/tip of medial malleolus
3. inability to bear weight both immediately and in the ED for 4 steps (unable to transfer weight twice onto each lower limb regardless of limping)

Question 11

list the Ottawa Ankle rules for foot x-rays

Answer 11

1. bone tenderness at base of 5th metatarsal
2. bone tenderness at navicular
3. inability to bear weight both immediately and in ED for 4 steps

Question 12

for an adult or child 5 years of age or older, which initial imaging procedure is most appropriate if they suffered an acute trauma to the ankle or they have persistent pain for more than 1 week but less than 3 weeks after an acute trauma to the ankle and they meet the Ottawa Ankle rules?

Answer 12

X-rays of ankle

Question 13

for an adult or child 5 years or older, what initial imaging procedure is most appropriate if they have an acute trauma to the ankle but no exclusionary criteria and do not meet the Ottawa Ankle Rules?

Answer 13

No imaging requried

Question 14

for an adult or child 5 years or older, what initial imaging procedure is most appropriate if:

• they had an acute trauma to the ankle
• exclusion criteria are present (neuro disoder, neuropathy, other)
• do not meet Ottawa Ankle Rules

Answer 14

Radiography of Ankle

Question 15

what initial imaging procedure is most appropriate for an adult/child older than 5 with an acute trauma to the foot and the Ottawa rules are positive?

Answer 15

radiography of foot

radiography of foot w/weightbearing

Question 16

what initial imaging procedure is most appropriate for an adult/child older than 5 with an acute trauma to the foot and the Ottawa rules are negative; but there is a suspected pathology in an anatomic area not addressed by Ottawa Rules?

Answer 16

radiography foot

radiography foot w/weightbearing

Question 17

what initial imaging is most appropriate for someone with chronic ankle pain?

Answer 17

X-ray ankle

Question 18

what next study is most appropriate for someone with chronic ankle pain but ankle radiographs are normal and there is suspected osteochondral lesions?

Answer 18

MRI ankle

Question 19

what next study is most appropriate for someone with chronic ankle pain and ankle radiographs are normal/nonspecific and there is a suspected tendon abnormality?

Answer 19

MRI ankle

USI ankle

Question 20

what next study is most appropriate for someone with chronic ankle pain, ankle radiographs are normal and pain is of uncertain etiology?

Answer 20

MRI ankle

Question 21

what initial study is most appropriate for chronic ankle pain with unknown etiology?

Answer 21

radiography foot