the radiology of metabolic disease

Question 1

different types of imaging

Answer 1

x-rays and CTs - white = more dense

bone densitometry

MRI - look at biochemical composition of underlying materials
radionucleotide bone scans or nucleomedicine studies - look at bone turnover, areas ofnhigh turnover eg with degenerative disease show up darker

–

x ray, ct and bone densitometry look at density

Question 2

what is pathology

Answer 2

a disease process that gives rise to symptoms, signs and biochemical disturbances and changes in imaging appearance

Question 3

what is a radiological sign

Answer 3

a change in image appearancem whether structural or functional that may point towards a pathology

Question 4

what is osteoporosis *

Answer 4

decreased quantity of bone mass - imbalance of bone structure

microstructure normal - just less of it

fragility fractures

deformity

pain

Question 5

how do you diagnose osteoporosis *

Answer 5

bone densitometry - DEXA scan

measure of BMD

compares BMD to normal reference databases and gives T-score (ref database white adult premenopausal female) - normally used, and z-score (ref database age and sex matched)

T score -1.5to-2,5 osteopenia

<-2.5 = osteoporosis

you image lumbar spine and hip

FRAX - enter parameters and it gives you liklihood of major fracture in 10yrs and guidelines

Question 6

radiology of osteoporosis *

Answer 6

(difficult to separate from malacia)

loss of cortical bone/thinning of cortex

loss of trabeculae

insufficiency fractures

bone too dark

Question 7

what are insufficiency fractures *

Answer 7

stress fractures due to normal stress on abnormal bones

common at - femoral neck, sacrum, vertebral bodies, pubic rami

Question 8

imaging of insufficiency fractures *

Answer 8

Xray/CT - initially normal, get get periosteal reaction and callus, more commonly increased sclerosis around fracture lines

MRI - bone oedema if acute setting, low signal on T1 high in T2 or STIR

bone scan - increased osteoblastic activity, ie increased uptake as bone attempts to heal

Question 9

example of an insufficiency fracture - x ray *

Answer 9

normally have dense bone in region because area of high pressure

people with osteoporosis likely to have a fracture here

Question 10

osteoporosis bone scan *

Answer 10

areas of increased uptake

honda sign in iliac region - pathonomonic of a stress fracture

Question 11

osteoporosis on MRI *

Answer 11

ileum is dark and sacrum is white - becasue of bone oedema

given right history - white is diagnostic of an insufficiency fracture

Question 12

osteoporosis on CT *

Answer 12

lucent line of fracture

increased density around fracture - attempt to rebuild

Question 13

what is osteomalacia &

Answer 13

decreased bone mineral - osteopenic bones, soft bones

too much unmineralised osteoid: looser zone

may have compensatory secondary hyperparathyroidism if ca stays low

Question 14

radiology of osteomalacia *

Answer 14

depends on age and closure of epiphysial plate

osteomalcia - mature skeleton

• osteopenia
• looser’s zones
• codfish vertebrae
• bending deformities

rickets

• before growth plate closure
• radiological signs cented mainly to growth plates
• changes of osteomalacia

Question 15

what are looser’s zones *

Answer 15

pseudo/insufficiency fractures at high tensile stress areas - femoral neck, lateral scap, pubic rami, posterior prox ulnar, ribs

radiology - short lucent lines, irregular sclerotic healing - increase in density

Question 16

x ray of looser zones *

Answer 16

insufficiecy fracture

margins white - thicker

darker the whole bone is the less dense - have osteopenia

Question 17

what are codfish vertebrae and examples &

Answer 17

biconcave deformity in vertebrae

seen in osteoporosis and osteomalacia

Question 18

progression of vertebrae in radiology *

Answer 18

1 - normal whitish

2 - osteoporotic fractures, vertebrae collapsed or lost height

3 - codfish vertebrae and less dense

4 - collapse, codfish vertebrae, v dark - porosis and malacia

Question 19

radiological signs of rickets *

Answer 19

indistinct/frayed metaphyseal margin

widened growth plate without calcification

cuppling/splaying growth metaphyses due to weight bearing

enlargement of anterior ribs

osteopenia

Question 20

hand x rays showing rickets *

Answer 20

mataphysis splayed

margin of grwoth plate frayed

Question 21

chest and leg x ray of rickets *

Answer 21

bowing of legs

enlargement or fraying of anterior ends of ribs - rosary beads sign

Question 22

3 types of hyperthyroidism *

Answer 22

primary due to parathyroid adenoma - PTH up Ca down, phos down - bone resorption

secondary - due to other systemic biochemical imbalance, chronic kidney disease, rickets/osteomalacia - PTH up, ca down, phos normal or down - bone resorption and increased density

tertiary - PTH up, ca up, phos down - PTH not responding to external stimuli (autonomous(

Question 23

where can bone resorption take place in hyperparathyroidism *

Answer 23

subperiosteal

subchondral - underneath chondroid cartilages

intracortical

can get brown tumours

Question 24

what is seen is this x-ray of hyperparathyroidism *

Answer 24

on L of bone - normal - cortex sharp

on R of bone - irregular subperiotic reaction

Question 25

what can be seen in this x-ray of hyperparathyroidism *

Answer 25

glenoid fossa - normally thick piece of bone but here really dark (low BMD)

this is subchondral resorption

Question 26

what can be seen in this skull - hyperparathyroidism *

Answer 26

salt and pepper skull

areas of lucency formed by combination of bone resorption and brown tumour formation

Question 27

what can be seen in this x-ray - hyperparathyroidism *

Answer 27

brown tumour - which is a collection of giant cells, also called osteoclastoma

Question 28

what is renal osteodystrophy and what can be seen radiologically *

Answer 28

specific bone changes in pts with renal diseases

get osteomalacia and osteoporosis - dark bones with looser zones and codfish vertebrae

secondary hyperparathyroidism - get

• subperiosteal erosions and brown tumours,
• sclerosis (of vertebral end-plates giving a rugger jersey spine, increased densitiy),
• soft tissue calcification - seen in vessels anmd cartilages (chondral calcification) - white bits in joint this is calcification of mensiscus

Question 29

image of osteomalacia and porosis - renal osteodystrophy

Question 30

image of brown tumours and subperiosteal erosions - renal osteodystrophy *

Question 31

image of soft tissue calcification - renel osteodystrophy *

Question 32

what is rugger jersey spine *

Answer 32

when edges of vertebrae have sclerosis so are white and middle has malacia so is dark - gives a stripy appearance

Question 33

what is paget’s and what are the disease stages *

Answer 33

disease of bone remodelling

affects whole bone - doesnt jump across joints

lytic phase, mixed lytic/sclerotic phase/sclerotic phase

Question 34

symptoms of paget’s disease *

Answer 34

bone pain

deformity

spontaneous fractures

nerve entrapment - bone grows in sclerotic phase

spinal stenosis

deafness

osteogenic sarcoma

Question 35

biochem features of paget’s disease *

Answer 35

raised serum alk phos, urinary hydroxyproline and pyridine cross links

Question 36

radiology of paget’s disease *

Answer 36

depend on stage of paget’s but most people catch in sclerotic or mixed lytic/sclerotic phase

cortical thickening

bone expansion

coarsening of trabeculae

osteolytic, osteosclerotic and mixed lesions

osteoporosis circumscripta - in skull

Question 37

what can be seen on this radiolgy of paget’s disease *

Answer 37

fracture on L pic

on r pic - L ileum is darker- sclerotic phase - more cotex and trabeculae

Question 38

what can be seen on this x-ray and bone uptake scan *

Answer 38

x-ray - lucency and thick cortex

bone uptake - increased up take in 1 place of bone

Question 39

what can be seen in this radiology of pagets *

Answer 39

top R - vertebral body has thick cortex adn trabeculae are course, bigger than you woild expect it to be

bottom R - thickening of long bone

L - uptake of vertebtrae increased - micky mouse sign

Question 40

what cen be seen on this radiology of pagets disease *

Answer 40

thicker scalp

large dark areas due to lytic phase

this is osteoporosis circumscripta

Question 41

what can be seen on these images - pagents *

Answer 41

L - osteoporosis circumscripta - whole area is lytic

R - widening of femer and courseness of the trabeculae