Lecture 6 materials - radiogaph Flashcards
How are x-ray images made?
High-energy photons interact with tissue by absorption, transmission, and scatter
X-rays that pass through the patient interact with the detector/film to create a radiograph
What factors affect absorption vs transmission?
Density & tissue thickness, atomic number
As values increase, absorption increases and leads to more opaque (white) areas
What are the 5 radiographic opacities?
Gas (Lucent), Fat (2nd most lucent), Soft tissue & fluid (3rd most lucent), Mineral (2nd most opaque), metal (most opaque)
What type of compound is used to increase contrast?
Barium 56
What causes opacity?
Density, atomic number, object thickness
What is summation?
An increase in opacity due to superimposition of structures that are not in contact
What is border effacement?
When 2 structures of the same radiographic opacity are in contact and their margins can’t be distinguished
What are roentgen signs?
Description of your radiographic finding
Location, Margination, Number, Opacity, Shape, Size
What is an orthogonal view?
Two radiographs that take views that are 90 degrees to each other
What is a cranial-caudal view?
Proximal to the tarsus/carpus
What is a dorsopalmar/dorsoplantar view?
Distal to the antebrachiocarpal/tarsocrural joint
What is a mediolateral or lateral view?
Image travels mediolaterally (medial view to lateral view)
Images also named for the side that is down ‘lateral’ ‘dorsal’
What is craniocaudal view or dorsopalmar/plantar view?
Craniocaudal - extremities proximal to carpus
Dorsopalmar - extremities from carpus to distal
Dorsoplantar - extremities from tarsus to distal
How to make a craniocaudal hanging radiograph
Marker on Lateral side
Proximal up
How to make a lateral/oblique radiograph
Marker on dorsal/cranial side
Proximal up, animal facing left
Why are oblique views important?
They provide angles that may be distorted otherwise (summation, border effacement)
How to accomplish an oblique view
Dorsomedial to palarolateral (DMPLO)
Dorsolateral to Palmaromedial (DLPMO)
What does DLPMO stand for?
Dorsomedial border to Palmarolateral border
What bone of the carpus projects back in a radiograph? What view is this?
Ulnar carpal bone and accessory carpal bone DLPMO
In what view is the first carpal bone projected back?
DMPLO (dorsomedial palmarolateral)
In what view is the 2nd carpal bone and medial splint bone projected back?
Dorsomedial palmarolateral
Where does the majority of bone growth occur?
Metaphysis
What do growth plates look like in a radiograph?
Radiolucent line of cartilage that separates the metaphysis from the epiphysis
Same opacity as soft tissue, leaves an opaque scar when closed
What is the epiphysis
End of long bones, present between the physis and the joint