Other: Imaging

Question 1

How can a bone scan be used to monitor arthritis activity?

Answer 1

Can show increased vascularity around joints which accompanies synovitis

Question 2

What is an avulsion fracture?

Answer 2

Avulsion of soft tissue fragments cause fracture of the bone

Question 3

How could you tell the difference between a 5th MT base fracture in an adolescent and the normal anatomical accessory ossification centre?

Answer 3

Ossification centre is longitudinal, 5th MT base fractures are transverse

Arrow = normal apophysis, arrowheads are other ossification centres

Question 4

What is bone sclerosis?

Answer 4

Increased bone density

Question 5

What is an impacted fracture?

Answer 5

Axial force through the bone impacts the two bone ends together, so the bone appears sclerotic

Question 6

What does cortical involvement indicate when imaging a potential bone tumour?

Answer 6

Aggressive tumour and surgery should be considered before the tumour causes a pathological fracture

Question 7

What causes the loss of joint space in osteoarthritis?

Answer 7

Aymmetric cartilage wear leads to asymmetric joint space reduction

Question 8

What is the fabella?

Answer 8

Sesamoid within the lateral head of gastrocnemius, often visible posterior to the distal femur

Question 9

What does Codman triangle indicate when imaging a potential bone tumour?

Answer 9

Periosteal reaction which suggests a more slow-growing tumour

Question 10

Which joints are commonly affected in Reiter’s syndrome?

Answer 10

Scattered large lower limb joints, lower limb entheses

Question 11

What is the mechanism of injury in a spiral fracture?

Answer 11

Occur due to torsional (twisting) forces

Question 12

What causes subchondral cysts in osteoarthritis?

Answer 12

Synovial fluid dissects into bone, forming cysts

Question 13

What might be mistaken for a fracture of the posterior calcaneus in a child?

Answer 13

Fragmented accessory ossification centre

Question 14

How can US be used to monitor arthritis activity?

Answer 14

Colour Doppler US can show thickening of synovium and increased blood flow within it

Question 15

Name the x-ray views used to image the cervical spine

Answer 15

AP, lateral, odontiod peg (mouth open)

Question 16

What is the mechanism of injury in a comminuted fracture?

Answer 16

Generally a reflection of a higher energy injury (or poor bone quality)

Question 17

What is the mechanism of injury in an oblique fracture?

Answer 17

Occur with a shearing force

Question 18

What causes osteopenia in rheumatoid arthritis?

Answer 18

Hyperaemia causes bone demineralisation resulting in periarticular osteoporosis

Question 19

What is a segmental fracture?

Answer 19

Very unstable fracture that occurs when the bone is fractured in two separate places

Question 20

What are technetium bone scans useful for in imaging trauma?

Answer 20

Can be useful to detect stress fractures (e.g. hip, femur, tibia, fibula, 2nd metatarsal) as these may fail to show up on x-ray until hard callus begins to appear

Question 21

If a bony ring e.g. pelvis is injured, what should you be looking for on x-ray?

Answer 21

Two or more disruptions (fractures/dislocations)

Question 22

What is the best modality for imaging sciatica?

Answer 22

MRI - shows all disc prolapses, and even the preceeding disc dehydration

Question 23

What causes subchondral sclerosis in osteoarthritis?

Answer 23

Increase in subchondral bone vascularity and cellularity drives new bone formation, leading to sclerosis of subchondral bone

Question 24

What is the mechanism of injury in a transverse fracture?

Answer 24

Occur with pure bending force where the cortex on one side fails in compression and the cortex on the other side in tension

Question 25

Rounded sesamoid bones always present on the medial and lateral plantar aspect of which digit of the foot?

Answer 25

1st metatarsal head

Question 26

Which joints are commonly affected in ankylosing spondylitis?

Answer 26

Scattered large lower limb joints

Question 27

What is the ostrigonum?

Answer 27

Accessory ossification centre commonly seen posterior to the tallus

Question 28

What is the angulation of a fracture?

Answer 28

Describes the direction in which the distal fragment points towards, and the degree of this deformity

Question 29

Why should you always check for joint involvement when imaging trauma?

Answer 29

If not reduced properly patient will be predisposed to OA of that joint

Question 30

What is an x-ray used for in imaging trauma?

Answer 30

Can show fracture

Question 31

What is an CT used for in imaging trauma?

Answer 31

Used when fracture shown on x-ray but more detail is needed, or if x-ray is normal but there is high clinical suspicion of fracture

Question 32

What causes deformity in rheumatoid arthritis?

Answer 32

Erosion 'shortens' the bones, so the ligaments and capsule surrounding the joint becomes lax Inflammation softens ligaments, which stretch further Joint subluxation and deformity develop

Question 33

Name the radiographic features of rheumatoid arthritis

Answer 33

Soft tissue swelling, osteopenia, erosion, deformity

Question 34

What does a sunburst appearance indicate when imaging a potential bone tumour?

Answer 34

Periosteal reaction which suggests a more aggressive tumour

Question 35

Is a poorly defined zone of transition on imaging of a bone tumour is suggestive of a benign or malignant tumour?

Answer 35

Malignant

Question 36

How would you assess a potential acromioclavicular dislocation?

Answer 36

Assess bony alignment

Question 37

What is a displaced fracture?

Answer 37

Bone ends are no longer in contact

Question 38

How can MRI be used to monitor arthritis activity?

Answer 38

Can show periarticular bone marrow oedema - often precedes significant joint erosion/damage so provides early evidence of inflammatory joint disease

Question 39

What causes erosion in rheumatoid arthritis?

Answer 39

Inflamed thickend synovium (pannus) destroys bone, initially at the joint margins (marginal erosion is the hallmark of RA) With time bone erosion progresses, spreading across the joint

Question 40

What causes the formation of osteophytes in osteoarthritis?

Answer 40

Periosteal stimulation

Question 41

What is the rotation of a fracture?

Answer 41

Describes one type of fracture displacement where there has been a rotation of the distal fracture fragment in relation to the proximal portion

Question 42

What is a posterior fat pad sign indicative of?

Answer 42

Elbow trauma

Question 43

What causes soft tissue swelling in rheumatoid arthritis?

Answer 43

Synovial proliferation and reactive joint effusion

Question 44

What is a comminuted fracture?

Answer 44

Fractures with 3 or more fragments

Question 45

Which is the only modality to adequately show the spinal cord?

Answer 45

MRI

Question 46

What is the translation of a fracture?

Answer 46

Describes the movement of fractured bones away from each other

Question 47

Which joints are commonly affected in psoriatic arthritis?

Answer 47

Small joints of hands and feet (DIP joints, IP of great toe)

Question 48

What is an MRI used for in imaging trauma?

Answer 48

Undisplaced fractures as shows bone marrow in detail, also can show soft tissue damage

Question 49

Name the radiographic features of osteoarthritis

Answer 49

Loss of joint space, osteophytes, subchondral sclerosis, synovial cysts

Question 50

Name the x-ray views used to image the scaphoid

Answer 50

AP, lateral, two obliques