MBD - Radiology

Question 1

Summarise the MBD

Answer 1

Osteoporosis - decreased bone mass
Osteomalacia - decreased malaria
Hyperparathyroidism -
Secondary hyperparathyroidism and renal osteodystrophy
Osteopenia (reduced mineral content of bone)
Osteosclerosis - abnormal hardening of bone and increased bone density

Question 2

Describe the function of the radiology tool

Answer 2

X-rays: density
Bone densitometry: density and attenuation
CT scans: density and attenuation
MRI scans: chemical and water content

Question 3

Describe in the features of osteoporosis

Answer 3

Decreased quaintly of bone mass and but normal microstructure, normal biochemistry, fragility fractures, deformity and pain common

Question 4

Describe the features of osteomalacia

Answer 4

De to vitamin D deficiency, biochemistry: low Vit D, low/ normal Ca2+, high PTH. Inadequate/ delayed mineralisation of bone.

Radiology is proportional to age/ growth plate closure, too little mineral - osteopenia and soft bones bend and deform. Too much osteoid the losers zone (and pseudo fractures - occurs in pubic, femur, scapula, loser ribs). If Ca2+ stay low then secondary hyperparathyroidism may occur.

Codfish veterbrae

Question 5

Compare osteomalacia vs osteoporosis

Answer 5

Osteomalacia - less mineral, osteopenia, bend and bow before breaking, feature of codfish veterbrae

Osteoporosis: less bone, osteopenia, break bone, anterior wedging.

Question 6

Compare osteomalacia and rickets ( and describe the feature of rickets )

Answer 6

Osteomalacia: changes in mature bone, osteopenia, looters zone, codfish veterbrae, bending deformities.

Rickets: changes before growth plate closure, changes related to growth plates dominate, changes of osteomalacia co-exist.

Rickets: metaphysis (area between the epiphysis and diaphysis) has the most rapid growth and thus shows the obvious chnages: frayed metaphyseal plate, widened growth plate, splaying due to weight bearing, rickets rosary, bowing of weight bearing legs, osteopenia.

Question 7

Describe the features of hyperparathyroidism

Answer 7

1. Primary: PTH adenoma (high PTH, high Ca, low phosphate)
2. Secondary: vitamin D deficiency (renal failure, low light, impaired liver - high PTH, low normal Ca, low/ normal Phosphate).
3. Tertiary: autonomous production of PTH (high PTH, high Ca, low phosphate)

Radiology: primary (high Ca) > bone resorption, secondary (low/normal Ca) osteodystrophy, resorption/increased density (due to PTH features)

Bone resorption: sub periosteal (affects radius and middle ring fingers), subchondral, intracortical, brown tumours,

Question 8

Describe renal osteodystrophy

Answer 8

Radiology: osteomalacia, osteoporosis, and secondary hyperparathyroidism features.