Imaging the Skeleton

Question 1

why are radiological images taken

Answer 1

Images taken for assessment of:

• Trauma,
• Degenerative diseases
• Metabolic diseases
• Infections
• Neo-plasms

Question 2

what do lucent lesions of the bone look like

Answer 2

dark areas (leucent region means that it looked darker) – this suggests that the bone is thinner at that point

Question 3

what do Sclerotic lesions of the bones look like

Answer 3

• these are whiter areas

– this suggests that there is more density and more bone tissue therefore it stops more of the x rays getting through

Question 4

what is a periosteal reaction

Answer 4

– loss of smooth appearance of the edges of bones

– have the bone precursor cells in the periosteum therefore you loose the smooth appearances of the edges of the bone

Question 5

what do soft tissue calcifications look like

Answer 5

– white patches in the soft tissue
– this is an indication that you have abnormal bone formation or an abnormal calcification in a tendon or a ligament that you shouldn’t have

Question 6

what is osteopenia

Answer 6

– localised reduction in bone density
– this is a bigger area, of reduction in bone density
– precurosor to osteoporosis

Question 7

what is osteonecrosis

Answer 7

• death of bone with loss of shape of the bones

Question 8

what are fractures and what do they look like in the x ray

Answer 8

– discontinuity of bone,

- black lines separating pieces of the bone, bits of bone that is broken off that you can see

Question 9

what is orthapaedic hardware

Answer 9

• metal and plastic

Question 10

what is joint integrity

Answer 10

• loss of joint space and loss of joint orientation

Question 11

what is the difference in what you can view in internal rotation and in external rotation in the humerus

Answer 11

• In external rotation the rotator cuff muscles pull the greater tubersotiy and cause the humerus to rotate laterally so you see more of the lesser tubersosity
• In internal roation subscapularis is acting see less of the lesser tuberosity

Question 12

why do some bones show gaps between them that can look like fractures

Answer 12

• epiphyseal plate this is when the cartilage is not calcified and the bone is still growing, this can be seen in children

Question 13

what are you considering when looking at abnormal x rays

Answer 13

• Shape, size and or orientation of the bones and joint surfaces
• Breaks in the bone
• Extra bone (calcification)
• Loss of bone
• Foreign objects

Question 14

what is the problem with x rays

Answer 14

• bone in front can obscure bone behind and therefore you are not able to view the bone behind unless you view it from a different angle therefore different views of x rays need to be used

Question 15

what are the limitations of x rays

Answer 15

• only calcified tissue shows up clearly
• soft tissue does not show up
• not sensitive for example you loose 30% of bone mass before it shows up on the x ray
• bone in front can obscure the internal bone processes or structures behind
• processes taking place inside the bone cannot be seen - avascular necrosis and osteomyelitis

Question 16

what can iodine be used for

Answer 16

Inject iodine or air into the joint as this changes the density of the shoft tissues therefore you can see the shoulder joint and see how big the joint capsule is and how it drapes into the axillar

Question 17

what is dexa scan used to do

Answer 17

• checks bone density

- can also be used for body fat

Question 18

how does a dexa scan work

Answer 18

Uses 2 different low energy x-ray sources.

Question 19

why is it a good thing to use 2 different low energy x ray sources

Answer 19

Using 2 different x-ray sources improves accuracy