Outline the production of a radiograph.
Electrons are produced by a heating filament. These are then fired at a tungsten block. This excited the tungsten atoms leading to the emission of X-rays. These penetrate tissue and get absorbed to different degrees, producing the desired image.
Attenuation
Stopping X-ray photons
Complete exposure
No attenuation, black
Unexposed
Full attenuation, white
Outline the five basic radiographic opacities.
Black - air, Dark grey - fat, Mid-grey - soft tissue/ fluid, Light grey - mineral (bone), White - metallic
Apparent opacity of materials on radiographs depends upon..
Atomic number, physical density, thickness
Collimation
A scatter plate allows viewing of all four edges of the radiograph
Outline the mnemonic approach to assessing radiographs.
Alignment, bones, cartilage/joints, devices, everything else (soft tissue)
Identify the radiographic signs which should always be checked when assessing a lesion.
Number, size (measure), shape, location, opacity
What is the mass effect?
Masses lead to disruption of normal anatomy
Effacement
Unable to see the edge of a structure
