Radiology Flashcards
Radiopaque
White (or relatively white) areas on the radiograph (areas that absorb x-rays)
Radiolucent
Black (or relatively black) areas on the radiograph (areas that do not absorb x-rays)
ALARA
As Low As Reasonably Achievable
3 means to achieve ALARA
- Increase distance
- decrease time
- Use of sheilding
Opacity interface
Boundary/distinction between opacities
Contrast
The degree of opacity difference between adjacent structures on a radio graph
Magnification
Enlargement of an image relative to actual size
Distortion
Image misrepresents true shape or position of object (caused by unequal magnification of object)
Orthogonal views
Two radiograph views taken at a 90 degree angle to eachother
Summation
Occurs when parts of objects in different planes are superimposed. The overlapping portions appear to have opacity equal to the sum of the individual tissues
Silhouette Sign
Structures/materials of same radiographic opacity in contact with one another, result in loss of opacity interface (no contrast)
Border effacement
A component of the silhouette sign. Borders of individual materials cannot be resolved
What does “left lateral view” mean
The animal is laying on its left side (left side on cassette), which means the x-ray beam would be coming down and entering on the animals right side
7 radiographic signs (Roentgen signs) used to describe normal and abnormal structures
- Opacity
- Size
- Shape
- Number
- Location/Position/Alignment
- Margination (border margins, i.e.lobular)
- Function (Not all will have functions, especially abnormalities)
5 Radiographic Opacities
- Blackest = air(gas) opacity
- Dark Grey = fat opacity
- Light Grey = Fluid (water, blood, urine)/Soft tissue(muscles or organs) opacity
- Grey White = mineral(bone) opacity
- Whitest = Metal opacity
