Radiographic Principles Flashcards
What are the radiographic technique principles?
Minimum of 2 orthagonal views
o ML
o CrCd (CdCr)
Radiographs of long bones should include both proximal and distal adjacent joints.
Views of joints should include 1/3 of the bone above and below.
Supplementary films include
o Stressed views
o Controlateral limb for comparison
o Bone survey laterals of all 4 limbs.
Repeat if not of diagnostic quality.
Label the anatomical structures of the femur
What are the 2 different ossifications creating bone development?
- Intramembranous ossification: directly converts mesenchymal cells into bone that forms the Flat bones, skull, and most facial bones.
- Endochondral ossification: The process by which embryonic cartilaginous model of most bones contributes to longitudinal growth and is gradually replaced by bone.
Typically, each long bone has 3 centres of ossification:
- 1 in diaphysis (Primary ossification centre) – develops in diaphysis, growing and lengthening
- 2 in each epiphysis (secondary ossification centre)
o Epiphysis: Bone length
o Apophysis bone shape.
Anconeal process is a separate ossification centre in large breed dogs.
Coronoid process > in some dogs medial coronoid process develops as a separate ossification centre.
- Accessory ossification centre: sesamoid bones and focal areas of mineralisation near joints
What are the radiographic features of endochondral bone development?
- Radiolucent space between epiphysis and metaphysis = physis/growth plate.
- On metaphyseal side of physis see increased bone opacity
- Metaphyseal periosteal surface may be uneven and hazy due to remodelling (cut back zone)
Label this immature canine femur
Label the following radiograph
What does A,B,C,D and E represent?
Label the following hip and stifle
Label the following carpal and tarsal epiphysis
What are sesamoid bones?
Small smooth rounded structures that form where tendons pass over a joint.
Reduce friction, protect and stabilise the tendon.
Usually only one surface is articular.
Where are sesamoid bones commonly found in the dog?
Stifle
Elbow
Tarsus
MC and MT phalangeal joints
Function and location of accessory ossification centres
Many locations usually near joints or embedded in joint capsule
Generally represent normal variants that need to be differentiated from pathology.
What are these bones?
Clavicles
Where are the Accessory ossification centres located in the pelvis?
- Acetabular rim: craniodorsal margin may not completely fuse
- Ossicle medial to lessor trochanter (curved arrow)
Ossicle cranial to iliopubic eminence (straight arrow) - Mineralization in tendon of gluteal m. proximal to greater trochanter (not a true ossification centre)
Where else can accessory ossification centres be found?
Coronoid process
- Incomplete ossification associated with elbow dysplasia
Os penis
- Usually a single ossification centre but can develop from 2 or more centres
- Incomplete ossification can be confused with a fracture.
