SA MSK Radiography and Radiology

Question 1

What must the screens used for viewing radiographs be like? E.g. what qualities should it have?

Answer 1

• Viewing equipment (screens)
  
  • Must have sufficient luminance and spatial resolution
  • This applies to all monitors used for diagnosis, not just the acquisition unit
  • Good quality, high brightness/high resolution LCD screens fulfil the requirements
  • However, many laptop screens, for example, do not ….. And tablet/phone screens may be too small!
  • Whatever screen is used, viewing performance reduce background lighting

Question 2

What radiographic signs can be used to evaluate boones?

Answer 2

Number

Location

Size

Shape

Margination

Radiopacity (including internal architecture)

Question 3

How should you orientate a radiograph when looking at it?

Answer 3

Proximal part of limb at top of the image, distal at bottom

Medial or lateral to left OR right, doesn’t matter which - as long as you always do the same thing when looking at radiographs.

If ventrodorsal / dorsoventral views - always have the LEFT hand side of the body at the RIGHT of the image, so it is as if you are looking at the patient

Question 4

Is this radiograph (soz its bad quality, blame lecture), is the thing circled:

Artefact

Normal anatomy

Pathology?

Answer 4

The lucent line circled is actually NORMAL ANATOMY

It is a nutrient foramen

Question 5

What is a nutrient foramen?

Answer 5

All bones possess larger or smaller foramina (openings) for the entrance of blood-vessels; these are known as the nutrient foramina, and are particularly large in the shafts of the larger long bones, where they lead into a nutrient canal, which extends into the medullary cavity

Question 6

Is what is circlede here:

Artefact

Normal anatomy

Pathology?

Where is the object in question located? What is it and what can it be a sign of?

Answer 6

Lump of bone on proximal edge of trochlear ridge - PATHOLOGY.

No normal structure here (circled = little osteophyte), only sign the dog had that it had degenerative joint disease

Question 7

What is circled here? Is it

Artefact

Pathology

Normal Anatomy?

Why is it visable?

Answer 7

Circled - divot within femur just proximal to one of the condyles - it is NORMAL ANATOMY.

This is the depression where biceps femoris attaches to the femur. Reason we can see it so well as there is rotation of the stifle, condyles not aligned, it had exposed this area more than normal.

Question 8

What can a divot in the femur be caused by as part of normal anatomy?

Answer 8

This is the depression where biceps femoris attaches to the femur. Reason we can see it on a radiograph sometimes is because there is likely rotation of the stifle, condyles not aligned, so it has exposed this area more than normal.

Question 9

Which stifle is normal - left or right? Why?

Answer 9

• Normal stifle LEFT
• Joint effusion, arthritic stifle RIGHT - soft tissue swelling
• Infrapatellar fat pad - can see patellar ligament
• Fascial planes in normal limb is quite straight and closely applied to bone, in effusion joint it is caudally displaced (blue arrow at back)

Question 10

What should you be ensure to check when you have a fractured pelvis?

Answer 10

Fractured pelvis - always check urinary tract! To check urethra and bladder intact

Soft tissue is very important

Question 11

How can bone react to pathology processes?

Answer 11

Bone reacts to pathological processes in a limited number of ways e.g. change in contour, change in alignement, increase or decreased bone mass

Question 12

What are some things you can look at the assess whether a bone lesion is aggressive or non-aggressive?

Answer 12

Look at nature of:

• Bone destruction (lysis)
• Periosteal reaction
• Lytic edge character
• Cortical disruption
• Transitions from normal to abnormal bone
• Rate of change (10-14 days)

You can get different appearances in different parts of lesions or aspects of change - so always choose the most aggressive appearance

Question 13

How can patterns of bone lysis be different in aggressive or non-aggressive lesions in bone? E.g. how do they look different on radiographs?

Answer 13

Can have geographic lesions - aggressive or not depending on area, see pictures attached

Moth eaten lysis - less aggressive than permeative

Permeative lysis - more aggressive

Question 14

How can the periosteal reactions differ between aggressive and non-aggressive?

Answer 14

Question 15

A 10 year old Rottweiler presented with progressive left forelimb lameness, pain and swelling.

1. Describe the lesions under the following headings:
2. Any lysis of bone?
3. Appeareance of the periosteal reaction?
4. What is the edge of the lytic focus like?
5. What is the transition zone?
6. Is there cortical destruction?
7. How aggressive is the lesion?
8. Top 2 differential diagnoses?

Answer 15

• Clear lesion
• Areas of reduced opacity, with lysis of bone
• Moth eaten or permeative
• Thick brush like areas, but some wispy new bone coming out.
• Edge of lytic focus: poorly defined
• Transition zone: (the zone between edge of lysis and what you would consider to be normal bone) - wide.
• Cortical destruction: certain areas of cortical defects but some areas where there is complete cortex destruction
• Aggressiveness of the lesion: aggressive lesion. All the hallmarks of an aggressive lesion
• Top 2 different diagnoses for this lesion: malignant neoplasia and then osteomyelitis (more semi-aggressive though)
• Lesions originated probably at metaphysis. Important because there are some bone tumours, malignant, that had a predilection site for being in the metaphysis - osteosarcoma is one of those.

Question 16

Do you get lysis of bone with hypertrophic osteopathy?

Answer 16

No

Question 17

Where does osteosarcoma have a tendency to develop?

Answer 17

Has a tendency to develop in the metaphysis and ‘away from the elbow and towards the knee’

Question 18

A nine year old crossbreed dog presented with progressive R forelimb lameness and pain. Look at the lesion and describe it under the following headings:

1. Pattern of bone destruction
2. Periosteal reaction
3. Edge of lytic focus
4. Transition zone
5. Cortical destruction
6. Aggressive or non-aggressive?
7. Top DDs?
8. Diagnosis

Answer 18

• Pattern of bone destruction: there is some lysis, which is patchy in some places, but is one geographical area
• What is the periosteal reaction: it is fairly solid, a few striations which area parallel to cortex - lamellar
• Edge of lytic focus: well demarcated, possible some areas of sclerosis
• Transition zone: narrow
• Cortical destruction: a bit or irregularity, but cortex generally spared
• Based on observations, the lesion is possibly non-aggressive.
• Top DDs: benign neoplasia possibly, bone cyst possibly, osteomyelitis
• IT IS OSTEMYELITIS

Question 19

Can radiographic appearance prodive a definitive diagnosis?

Answer 19

It will NOT provide a definitive diagnosis unless its a fracture

Changes must be interpreted along with history, signalment, clinical findings and response to treatment when compiling differential list

Question 20

What are some tips on producing a good radiograph?

Answer 20

Follow the standard format

Be systematic and try not to jump to conclusions or miss out stages

Be succinct and concentrate on most significant information