Radiology of Metabolic Bone Disease

Question 1

Name two types of fractures seen in osteoporosis

Answer 1

Insufficiency fracture

Compression fracture

Question 2

What are insufficiency fractures?

Answer 2

Stress fractures resulting from normal stress on abnormal bone

Question 3

What are the common sites of fractures in osteoporosis?

Answer 3

Vertebral bodies
Sacrum
Pubic rami
NOF

Question 4

What changes are seen on an x-ray of an osteoporotic fracture?

Answer 4

Initially, nothing, but later:

Periosteal reaction
Callus formation
Sclerosis around fracture line
Codfish vertebrae

Question 5

What is seen on an MRI in osteoporosis and which type of MRI is this seen in?

Answer 5

Bone oedema - especially on T2 and STIR

On T1 you don’t see much

Question 6

What is seen in bone scans e.g. DEXA in osteoporosis and why?

Answer 6

Increased uptake due to osteoblastic activity

Question 7

State four radiological signs of osteomalacia

Answer 7

Osteopenia (looks more black than white due to low mineralisation)
Codfish vertebrae
Bending deformities
Looser’s zones

Question 8

What are Looser’s zones?

Answer 8

Insufficiency fractures in areas of high tensile stress

Question 9

State five areas where Looser’s zones occur in osteomalacia

Answer 9

Lateral scapula
Ribs
Posterior proximal ulna
Pubic rami
Medial proximal femur

Question 10

Describe the appearance of Looser’s zones

Answer 10

Short lucent lines, perpendicular to the bone’s edge, often surrounded by irregular sclerotic margins in white as the bone tries to repair itself

Question 11

State five radiological signs of Rickets

Answer 11

Frayed metaphyseal margin
Widened, splayed growth plate (due to weight bearing)
Enlargement of anterior ribs (Rachitic Rosary)
Osteopenia
Bending of bones

Question 12

What is a common sign of hyperparathyroidism?

Answer 12

Brown tumours especially at the skull (‘salt and pepper skull’)

Question 13

What are brown tumours and where do they commonly occur in hyperparathyroidism?

Answer 13

Bone resorption, commonly at:
Subperiosteal regions (around bone)
Subchondral regions (e.g. glenoid fossa)
Intracortical regions

Question 14

What do you call brown tumours in the skull?

Answer 14

Salt and pepper skull

Question 15

State three signs (and their common names) seen in secondary hyperparathyroidism, such as in renal osteodystrophy.

Answer 15

Brown tumours
Soft tissue calcification (e.g. in between knees)
Sclerosis, especially at vertebral end plates (increased bone density at top and bottom of each vertebra = rugger jersey spine)

Question 16

State the signs and conditions seen in renal osteodystrophy

Answer 16

Osteoporosis & osteomalacia

• osteopenic bone
• looser’s zones
• codfish vertebrae

Secondary hyperparathyroidism

• Brown tumours
• Soft tissue calcification
• increased sclerosis

Question 17

State five signs of Paget’s disease

Answer 17

Cortical thickening 
Bone expansion 
Coarsening of trabeculae 
Osteolytic regions (lucency) 
Osteosclerotic regions (too white)

Question 18

Paget’s disease of a vertebrae shows up as what on a DEXA scan?

Answer 18

Mickey mouse sign

Question 19

Paget’s disease lucency of the skull is called?

Answer 19

Osteoporosis circumscripta