Mid Sem Revision Flashcards
Why is diagnostic imaging used (3)
Essential tool too:
- facilitate diagnosis
- Increase our understanding of the pathophysiology
- grade seVerity of disease/injury
- facilitate treatment of injuries and pathological conditions
Radiation exposure- informed consent
Source of exposure
Natural radiation (airborne) - 1.2 mSv per year
Natural radiation (at sea level) - 0.3 mSv per year
Total natural radiation- 1.5 mSv per year
7- hour airplane flight - 0.02 mSv
Chest radiograph - 0.1 mSv
Standard chest CT -7 mSv
Standard hand/foot radiograph - 0.01msv
Typical cat scan - 1-14msv
Health stewardship
Any practitioner who has the ability to refer directly for imaging must have a sufficient level of knowledge to be ab,e to request appropriate investigations and understand the findings of reports as well as the ability to act appropriately on the findings
Ottawa ankle rules
An ankle X-ray is only required if there is any pain in the malleolar zone AND……
bone tenderness at the posterior edge or tip of the lateral malleolus
or
medial mall
OR
inability to WB immediately and in ED for 4 steps
Ottawa foot rules
A foot X-ray series is only required if there are any pain in mid foot zone and…
Bone tenderness at the base of the 5th metatarsal
Or
Bone tenderness at the navicular
Or inability to WB both immediately and in ED for 4 steps
Radiographic terminology
US - artery features
Hypoechoic, pulsatile, non compressible Dopple = pulsatile flow
US vein features
Hyperechoic, non pulsatilla, compressible
Doppler = continuous flow
US muscle features
Hypoeachoic with multiple hyperechoic lines
US tendon features
Hyperechoic with bright lines longitudinally or bright dots in transverse section
US nerves features
Viable hypo or hyperechoic with fascicular pattern
US ligament features
Hyperechoic bands with well defined borders
US bone features
Hyperechoic
Fracture terminology
Describing a fracture
- Anatomical site
- Type of fracture
- Alignment of fracture fragments
- Distinct features of fracture
- Direction / description of fracture lime
- More than 1 fracture? Impact on the joint
- Specific features of the tyPe of fractue
Describing fractures (7)
Which bone
Which side of a limb
L or R
Where exactly is it in the bone
Type of fracture
Acute, stress, pathological
Any other pertinent points
OA on a radiograph
Osteophytosis
Joint space narrowing
Subchondral sclerosis
Subchondral cyst formation.
Loose osseous body
Plain film angles - why do we measure?
Preparation for surgery
Grading the severity of deformities
Research
Tibial seasmoid position
Relationship of the tibial sesamoid to the long axis of the 1st metatarsal
Normal is medical to the long axis of the metatarsal
0 - seasmoid completely medial to mid-axial line
1 - seasmoid less than 50% overlapping the line
2 - sesamoid greater than 50% overlapping the line
3 - sesamoid completely lateral to the line
4 - normal
Os trigonum
Back of the talus bone
Os peroneum
Accessory bone on the cuboid closest to calc
Coalitions
Occurs in 6% of the population
Involves failure of the segmentation of the tarsal bones
Tarsal coalitions can be
Fibrousous (syndesmoisis)
Cartilaginous (synchondrosis)
Osseous (synostosis)
Tarsal coalition symptoms
Symptoms and joint restrictions become notable during puberty with growth plate closures
Typically presents as a painful rigid foot in marked pronation
Most common coalition forms
Calcaneo-navicular
Talo-navicular
Osteochondritis
Applied to a group of conditions in which no associated cause for avascular necrosis and be found
A compression, fragmentation or separation of a small fragment of bone usually at the bone end and involving the articular surface
Osteochondritws
Caused by impaired blood supply associated with repeated trauma
Typically occurs in children or adolescents often during phases of rapid growth and increased physical activity
3 types of osteochondritis
Crushing
Splitting
Pulling
