1- radiology principles

Question 1

in general what imaging shows bones/soft tissues best?

Answer 1

• x-ray shows bone outlines
• CT shows bone outlines in better detail and some soft tissue structures
• MRI shows bone outlines in less detail but very good soft tissue an discs, ligament, spinal cord nerves

Question 2

what are signs of normal spine in spinal imaging? (like things to look for)

Answer 2

1. consecutive vertebrae should have similar size
2. vertebrae should have good alignment

Question 3

what are ligaments function in spine?

Answer 3

they tether vertebrae together & responsible for spinal stability (like wrapper around polo packet - stack of polos themselves would just fall over, wrapper contains & gives stability)

Question 4

what imaging are ligaments seen on?

Answer 4

• not xrays or CT (but normal alignment suggests intact)
• seen on MRI (normal = black, damaged = light)

Question 5

when are MRI’s done for spinal trauma?

Answer 5

when patients have neurological deficit that’s not explained by x-ray or CT (or to see ligaments in better detail)

Question 6

how are spinal tumours seen on xray?

Answer 6

they are seen as invisible - when look on MRI you would be able to see tumour

Question 7

what can herniated disc cause?

Answer 7

herniated disc may press on spinal nerves and nerve pressure produces sciatica (can go into spinal cord)

Question 8

what imaging can you see spinal cord?

Answer 8

invisible on xray, poorly shown on CT, only sort of shown on MRI

Question 9

what are causes of spinal cord diseases?

Answer 9

• trauma
• tumour
• demyelination
• ischaemia

Question 10

what are most common and less common types of arthritis?

Answer 10

osteoarthritis & rheumatoid arthritis common

gout & seronegative arthritides are less common

Question 11

what happens in osteoarthritis?

Answer 11

cartilage is key thing - normally it fills gaps in between joints and is seen as black on xray. in OA cartilage is degraded so bones get close together and white is blurred all the way across

Question 12

what are osetophytes?

Answer 12

bony lumps that grow on bones of spine or around joints

Question 13

what is process of formation of subchondral cysts (a process in advanced osteoarthritis)?

Answer 13

cartilage erodes & pressure from joint movement causes tiny fractures, the synovial fluid seeps into these microfractures and makes subchondral cysts (fluid filled sacs trapped in bone), overtime this weakens bone structure

Question 14

what is rheumatoid arthritis?

Answer 14

autoimmune reaction to synovium (joint lining)

• usually affects joints symmetrically and only affects synovial joints

Question 15

how can rheumatoid arthritis lead to periarticular osteoporosis?

Answer 15

hyperaemia (more blood flow for the inflammation) causes bone demineralisation resulting in periarticular osteoporosis

Question 16

what is hallmark of rheumatoid arthritis?

Answer 16

marginal erosion of joint

Question 17

what is seronegative arthritides?

Answer 17

group of inflammatory arthritis
1. ankylosing spondylitis (stiff ridged inflammation spine)
2. psoriatic arthritis (alongside skin rash)
3. reiters syndrome (arthritis in response to infection)

Question 18

what is synovitis?

Answer 18

inflammation of joint & tendon sheath lining

Question 19

what is enthesitis?

Answer 19

inflammation of sites where ligaments & tendons attach to bone

Question 20

what are important differences between seronegative arthritides? (what joints are effected)

Answer 20

psoriatic = small joints of hands&feet

ankylosing spondylitis = scattered large lower limb joints

reiters = scattered large lower limb joints, lower limb entheses (sites where tendons attach to bone)