Radioloy of metabolic bone disease

Question 1

Imaging used in bone

Answer 1

X ray 
CT
Bone densitometry 
MRI 
radionuclide bone scans

Question 2

Which scans are based on density

Answer 2

X ray
CT
Bone densitometry

Question 3

What is MRI bone scan based on

Answer 3

Biochemical composition

Question 4

What are radionuclide scans based on

Answer 4

Bone turnover (bone formation, purely osteoclastic resorption won’t show up)

Question 5

What colour would fat show up as on mri

Answer 5

white

Question 6

Why would the inside of a vertebral bone be dark on MRI

Answer 6

Should be white (to show bone marrow which is fatty….) if dark… oedema or soft tissue lesion e.g. tumour

Question 7

What can happen on the bone marrow following radiotherapy

Answer 7

`Fatty changes to bone marrow

Question 8

In radionuclide bone scans, which areas appear dark

Answer 8

Increased bone turnover regions

Question 9

Which areas might have increased bone turnover and thus show up dark on nuclear medicine scan

Answer 9

Joints (bit of wear and tear)
Metabolic bone disorders
Fractures
Tumours

Question 10

Differentiate radiological sign with pathology

Answer 10

Pathology: A disease process that gives rise to symptoms, signs, biochemical disturbances and changes in imaging appearance.

Radiological sign  A change in imaging appearance, whether structural or functional, that may point towards a pathology

Question 11

What does microstructure of osteoporotic bone look like

Answer 11

Completely normal, just a lot less of it

Question 12

What happens to bones in osteoporosis

Answer 12

Fragility fractures, deformity otr pain

Question 13

Differentiate T score and Z score in dexa scans

Answer 13

▪ T-score (ref database white adult premenopausal females) ▪ Z-score (ref database age and sex matched)

Question 14

T score range for osteoporosis and osteopenia

Answer 14

T-score -1.5 to -2.5 = osteopenia; less than -2.5 = osteoporosis

Question 15

Which areas are commonly assessed on DEXA

Answer 15

Vertebrae and pelvis

look specifically at L2-L4

Question 16

T/F how low the BMD is (t score) is reflective of fracture risk and severity of osteoporosis

Answer 16

F

Question 17

What is used to assess risk of fracture

Answer 17

FRAX, BMD put in along with other risk factors, gives 10 year fracture risk

then look at nogg guidelines

Question 18

Radiology signs for osteoporosis (not DEXA but imaging)

Answer 18

Loss of cotical bone/thinning of cortex
Loss of trabeculae
Insufficiency fracture

Question 19

What is insufficiency fractures

Answer 19

Stress fractures: normal stress on absormal bone

Question 20

Common site for insufficiency fractures

Answer 20

Sacrum, underside of femoral head, vertebral bodies, pubic rami

Question 21

What is seen in insufficiency fractures:
XR/CT

MRI

BONE SCAN

Answer 21

XR/CT = normal initially, periosteal reaction/callus, increased sclerosis around fracture line (major)

MRI= Bone oedema i.e. low signal on T1, high signal on T2 and STIR

Bone scan= osteoblastic activity as bones try to heal

Question 22

Sign for insufficiency fracture at back of pelvis

Answer 22

Honda sign

Question 23

What is the pathology in osteomalacia

Answer 23

Unmineralised bones

osteopaenic and soft bones

Question 24

What zones do you get in osteomalacia

Answer 24

looser’s zones

Question 25

Radiology for osteomalacia depends on what

Answer 25

 Biochemistry: vit d low, calc: N/low, PTH up  Inadequate or delayed mineralisation  Radiology depends on age and closure of growth plate

Question 26

What may be found in osteomalacia

Answer 26

- looser's zone - osteopenia - mature skeleton - codfish vertebrae - bending deformity

Question 27

What might be seen in rickets

Answer 27

Before growth plate closure  Radiological signs centred mainly to growth plates  Changes of osteomalacia

Question 28

What are Looser's zone where do they occur

Answer 28

Pseudofractures Are also types of insufficiency fracture Medial proximal femur  Lateral scapula  Pubic rami  Posterior proximal ulna  Ribs

Question 29

What do looser zones look like

Answer 29

At right angle do the bone Irregular sclerotic margins Bone may be osteopaenic/expanded

Question 30

When are codfish vcertbrae seen AND WHAT IS IT

Answer 30

Osteoporosis and ostoepaenia Biconcave vertebrae

Question 31

Ricket what is seen on imaging

Answer 31

Frayed metaphyseal margin Widened growth plate without calcification Cupping/splaying metaphyses due to weight bearing Enlargement of anterior ribs  Osteopenia

Question 32

What is seen on imaging with primary and secondary HPT

Answer 32

Primary - increased bone resopriton Secondary- increased bone resorption and increased density

Question 33

Types of bone resorption

Answer 33

Subperiosteal  Subchondral  Intracortical  Brown tumours (if large)

Question 34

What does sub-periosteal resorption look like

Answer 34

No straightened edge to the bone (not like wavey but just not a definitive line)

Question 35

What do circular lucencies or small speckles of black on skull bone represent What is the name for lots of little spckles on skull

Answer 35

Intracortical Pepper pot sign

Question 36

Give an example of a lytic bone lesion found in primary HPT

Answer 36

Brown tumour

Question 37

t/f radiology can easily identify the cause of a lytic bone lesion

Answer 37

F.... look like infection, malignancy or brown tumour

Question 38

Outline pathogenesis of renal osteodrystrophy

Answer 38

Cannot excrete phosphate due to renal failure Phosphate can bind calcium (i.e. anion bound) so low free (ionised) calcium High phosphate and the low free calcium increases PTH which increases bone resorption Vit D decreases due to renal failure also increasing PTH Therefore you get 1. Osteoporosis due to increased bone resorption 2. Osteomalacia due to reduced bone mineralisation due to vit D decificiency SECONDARY HPT

Question 39

Which lesions could be seen in renal osteodystroph u

Answer 39

Subperiosteal erosions, brown tumours, Sclerosis – vertebral endplates giving a rugger jersey spine,  Soft tissue calcification (vessels, cartilages)

Question 40

What is rugger jersey sign

Answer 40

Occuring in renal osteodystrophy due to secondary HPT Increased density at the end plates and then increased lucency in between

Question 41

Giver an example of soft tissue calcification in secondary HPT

Answer 41

Menisci in the knee are white

Question 42

Differentiate density of sclerotic vs lytic lesions

Answer 42

Sclerotic is hardened and dense Lytic is not

Question 43

Outline the stages of pagets

Answer 43

lytic mixed lytic and sclerotic sclerotic

Question 44

Symptoms of pagets, bone and other wise

Answer 44

Bone: pain, derformity, fracture (same as osteoporosis) Other: NERVE ENTRAPMENT, spinal stenosis and deadness

Question 45

Biochemical signs in pagets

Answer 45

Increased Alk Phos.

Question 46

What are patients with pagets prone to

Answer 46

Osteogenic sarcoma

Question 47

Radiological signs in paget's

Answer 47

Cortical thickening  Bone expansion  Coarsening of trabeculae  Osteolytic, osteoclerotic and mixed lesions  Osteoporosis circumscripta (in lytic part)

Question 48

How can u distinguish pagets from the other diseases

Answer 48

Usually focal, not usually present in adjacejnt bone

Question 49

T/f the osteoporosis circumscripta is related to osteoporosis

Answer 49

f..... THIS IS JUST THE NAME FOR LUCENCY IN PAGET'S DISEASE

Question 50

Sign for the increase bone turnover sometimes seen in the spine in radionuclear medicine scans in pagets

Answer 50

Micky mouse sign