Musculoskleletal Imaging: Intro and General bone

Question 1

Bone is living tissue

Answer 1

it is dynamic

knowledge of the physiology and histology is essential to understanding radiographic changes associated with disease process

Question 2

Interpretation paradigm

Answer 2

• Soft tissue changes
• Osseous changes
  
  • periosteum
  • Cortex
  • Medulla
  • Zone and rate
• Classify lesion as Benign or aggressive
• Differentials

Question 3

Approach to interpretation

Answer 3

Signalment

patient age

Body condition and conformation

breed

previous injurties or surgeries

Question 4

Approach to interpretation:

Comparison

Answer 4

Radiograph opposite limb for comparison

Question 5

Soft tissue

Answer 5

• Evaluate visualization of Fascial Planes and margination of muscle groups
• Edema, hemorrhage, inflammation of tumor infiltration will result in loss of visualization of fascial planes
• Gaw, swelling or mineralization of soft tissue will cause changes in opacity

Question 6

Opacity Changes:

Decreased

Answer 6

of soft tissue due to gass present in the soft tissue

Question 7

Opacity Changes:

Increased opacity

Answer 7

of soft tissue due to increased soft tissue density, mineralization or foreign material ballistics

Question 8

Opacity Changes:

Gas in soft tissues

Answer 8

areas of decreased opacity within soft tissues

Emphysema

Due to:

open would

Gas producing organisms

Latrogenic (post-operatively or following needle puncture)

Question 9

Soft Tissue:

Mineralization

Answer 9

Increased mineral opacity within the soft tissue

Common causes:

metastatic mineralization

Dystrophic mineralization

Question 10

Metastatic mineralization

Answer 10

Mineralization of normal tissue due to elevated serum calcium and/or phosphorus levels

Question 11

Dystrophic Mineralization

Answer 11

Mineralization of dead, degeneratie, or devitalized tissue

Question 12

metal opacity

Answer 12

ballistics

Iatrogenic (surgical)

Question 13

Evaluating Bony Lesions

Answer 13

• Proximal to distal
• Outside to inside
  
  • soft tissue
  • periosteum
  • cortex
  • Edosteum
  • Medullary canal
• Include joint above and joint below

Question 14

Lesion Distribution

Answer 14

monostotic

polyostotic

Focal

generalized

symmetrical

asymmetrical

Predilection sites

Question 15

Osteosclerosis

Answer 15

Radiographic term fro increased bone opacity

Rare in veterinry medicine

Usually artifactual or due to superimpostion

Question 16

Osteopenia

Answer 16

Radiographic term for decreased bone opacity

Question 17

Osteopenia:

Osteoporosis

Answer 17

Loss of bone mass

Quantity of bone decreased

Existent bone is of normal composition

Question 18

Osteopenia:

Osteomalacia

Answer 18

Loss of mineralization of bone matrix

Quality of bone is decreased

Increased percentage of non-calcified osteoid and/or insufficient mineralization of osteoid matrix

Question 19

Generalized bone lesions:

Causes of generalized osteopenia

Answer 19

metabolic disease

Nutritional disease

Disuse

Congenital disease - osteogenesis imperfecta

Question 20

Answer 20

osteopenia

Question 21

Wolff’s Law

Answer 21

Bone grows and remodels it responds to forces or demands placed on it

Question 22

Evaluating Bony Lesions

Answer 22

• Bone response to injury and disease
  
  • new bone formation, resorption or lysis or combination
  • May require biopsy for diagnosis
• Radiographs used to determine lesion significance
  
  • aggressiveness, activity, duration
• Radiographic changes lag behind clinical abnormalitites
  
  • Lytic changes: may take 5-7 days to be visible radiographically
  • Productive/Blastic changes: may take 10-14 days to be visible radiographically

Question 23

Evaluating Bony Lesions:

Non-aggressive vs. Aggressive

Answer 23

1. Location and number of lesions
2. Pattern of lysis
3. Pattern of new bone production
4. Cortical changes
5. Transition zone to normal bone
6. Change in lesion appearance over time

Question 24

Rate of Change

Answer 24

Radiographic appearance of an aggressive lesion will change rapidly relative to a non-aggressive lesion

radiographs obtained 10-14 days after initial fils may show a change in appearance of the lesion if it is aggressive

Non-aggressive lesions will appear the same due to the slower rate of change

Question 25

Response of Bone to injury" Osteoblastic Change

Answer 25

periosteal reactions Callus Osteophytes and enthesophytes

Question 26

Response of bone to injury: Ostelystic Change

Answer 26

geographic moth eaten permeative

Question 27

Periosteal Reactions

Answer 27

* Is not unique to the disease process * Anything that causes the periosteum to be elevated or stripped from the bone will results in a periosteal reaction * Appearance of the periosteal reaction is rather an indication of the speed of the disease process and therefore the affressiveness of the pathology present * Classification of aggressiveness is based on organization of new bone * More disorganized the new bone formation → the more aggressive the lesion

Question 28

Solid periosteal reaction

Answer 28

bone completely fills the area under the reaction More chronic, the more solid/mineralized The surface can be smooth or undulating Usually non-aggressive Callus

Question 29

Lamellated Periosteal Reaction

Answer 29

Layered or “onion skin” appearance Indicates a cyclic or intermittent process More aggressive than solid, smooth new bone but usually associated with benign process

Question 30

Spiculated periosteal reaction

Answer 30

* Periosteal reaction perpendicular to the cortex - along the sharpey's fibers * Can appear like _Columns of bone_ * Columnar seen with diseases like hypertrophic osteopathy * Often seen with aggressive disease

Question 31

Amorphous periosteal reaction

Answer 31

* Bone is formed in a disorganized manner * Mineralization of the soft tissue adjacent to the bone pathology * Process may destroy or displace spicules of bone as they are being formed * Most aggressive reaction * Most often neoplasitc in origin

Question 32

Geographic Lysis

Answer 32

* Large area of lysis * Lesion may appear expansile * Well-defined with short zone of transition * Nonaggressive or aggresive; however, usually considered least aggressive from of lysis * Bone cysts, multiple myeloma * Sclerotic margin +/-

Question 33

Moth-eaten lysis

Answer 33

* Multiple smaller areas of lysis * These areas may become confluent to form a larger area of lysis * Usually indistinct margins * Usually aggressive * osteomyelitis, or neoplasia

Question 34

permeative lysis

Answer 34

numerous small or pinpoint areas of lysis Margins are indistinct As permeative lysis progresses, the areas amalgamate to look moth eaten Most aggressive patterns usually associated with neoplasia