MSK - Metabolic/Hematologic Bone Disease

Question 1

What processes can cause a pseudo-permeative pattern i.e. multiple small cortical holes? (3)

Answer 1

Osteoporosis, hemangioma and radiation

+ multiple myeloma

Question 2

Features of osteomalacia (Rickets) in children

Answer 2

Flared and irregular epiphyses, bowing long bones, Rachetic rosary

Question 3

Most common cause of osteomalacia

Answer 3

Renal osteodystrophy

Question 4

Signs of hyperparathyroidism

Answer 4

Subperiosteal resorption - most commonly radial aspect of proximal and middle 2nd and 3rd phalanges

Subchondral resorption: distal clavicle osteolysis, SI joints, proximal tibia

Osteosclerosis (spine - Rugger Jersey, or more difffuse)

Brown tumour

Salt and pepper skull

Question 5

Features of acromegaly

Answer 5

1) Neuro: Skull thickening, enlarged sinuses and enlarged sella
2) Spade appearance of terminal tufts of distal phalanges
3) Early DJD
4) Soft tissue thickening (heel pad >2.5 cm)

Question 6

List the processes associated with increased bone density (osteosclerosis)

Answer 6

Renal osteodystrophy, sickle cell, myelofibrosis, osteopetrosis, pyknodysotosis, mets, mastocytosis, paget disease, athletes, fluorosis

Question 7

Features of osteopetrosis

Answer 7

Diffuse bony sclerosis, bone-in-bone appearance of vertebrae, sandwich vertebrae (sclerosis does not extend all the way to the end of the vertebral body), extremely brittle bones = multiple fractures

Question 8

Features of pyknodysostosis (i.e. Toulouse-Lautrec)

Answer 8

Short stature, distal phalangeal and distal clavicle hypoplasia, delayed suture closure +/-Wormian bones, diffuse skeletal sclerosis including spine

Question 9

Imaging findings scurvy

Answer 9

Osteopenia
Subperiosteal hemorrhage
Dense metaphyseal calcification (Frankel) with underlying lucency (Trummerfeld)
Wimberger ring sing (opaque ring around epiphyses)
Pelkin spur (result from metaphyseal cupping)

Question 10

Imaging findings osteomalacia

Answer 10

Osteopenia
Looser zone (cortical stress fracture most commonly seen in medial proximal femur, scapula and pubic bones)

Question 11

Imaging findings acromegaly

Answer 11

• Gigantism due to longitudinal growth when growth plates still open
• Spade-like tufts, beak-like osteophytes metacarpal heads, joint space widening/narrowing
• Enlarged jaw, frontal sinuses and thick skull
• Thickening of heel-pad (~2.5 cm)

Question 12

Key imaging findings in hyperPTH

Answer 12

• Salt and pepper skull
• Subperiosteal resorption along radial aspect of 2nd/3rd middle phalanges, proximal medial tibia
• Distal clavicle osteolysis
• Brown tumours
• Diffuse osteopenia
• Soft tissue calcification (secondary hyperPTH)
• CPPD (primary hyperPTH)
• Insufficiency fractures

Question 13

What is renal osteodystrophy? Imaging findings?

Answer 13

Combined effects of abnormal Vitamin D metabolism (osteomalacia) and secondary hyperPTH from prolonged renal failure
- Pt with CKD also at risk for OM, AVN, amyloidosis

Imaging shows findings of osteomalacia and hyperPTH - including osteopenia, subperiosteal resorption, soft tissue calcifications, rugger jersey spine

Question 14

Imaging findings in hypothyroidism

Answer 14

Delayed skeletal maturity**, dental immaturity, bullet-shaped vertebral bodies, Wormian bones in skull

Question 15

Imaging findings in hypoPTH

Answer 15

Metastatic calcium deposits (in soft tissues and BG)

Question 16

Imaging findings in pseudohypoPTH

Answer 16

Defect in PTH receptors
Short stature, short metacarpals (4th, 5th or thumb)
DDx: Turner’s syndrome

Question 17

Imaging findings thyroid acropachy

Answer 17

Diaphyseal periosteal reaction, multiple long bones including metacarpals, metatarsals, phalanges

Question 18

Most common location of Pagets

Answer 18

Skull - sharply marginated geographic lytic region (osteoporosis circumscripta), cotton wool skull (mixed phase)
Vertetebral bodies - picture frame or ivory vertebra
Pelvis - trabecular coarsening, cortical thickening (look at iliopectineal and ilioischial line)
Long bones - prox to distal, lytic, blade of grass/flame shaped margins, eventual bowing and coxa vara

Question 19

Complications of Paget’s (4)

Answer 19

Pathologic fracture, malignant degeneration to osteosarcoma**, secondary GCT, secondary OA

Question 20

Imaging findings Gaucher disease (lysosomal storage disease)

Answer 20

• BONE INFARCTS
• Erlenmeyer flask deformity long bones
• H-shaped vertebral bodies
• Hepatosplenomegaly (big spleen, versus auto-infarcted spleen in sickle cell)

Question 21

Findings in Sickle Cell Disease

Answer 21

Bone infarcts
AVN
H-shaped vertebral bodies
Dactylitis in young children**
Osteomyelitis (typically Salmonella)
Marrow replacement (diffuse low T1 signal, medullary expansion)
Osteopenia + inc. risk insufficiency fracture
Hair on end striations (skull)

Question 22

Imaging findings in thalassemia

Answer 22

• Hair on end skull
• Maxillary hypertrophy
• Diffuse osteopenia in the pelvic bones (cortical thinning, medullary expansion, coarsened trabeculations)
• Extra-medullary hematopoiesis
• Expanded ribs
• Hepatosplenomegaly