Physics
What is the basic form of energy used to create radiographic images.
Electromagnetic radiation
A projection where the beam enters anterior and exits posterior.
What is AP projection
This refers to the darkness of the radiographic image.
What is density
The principle of keeping dose “as low as reasonably achievable.”
What is ALARA
This structure appears the darkest on an X-ray.
What is air.
What controls the energy and penetrating ability of the X-ray beam.
What is kVp (kilovoltage peak)
In a properly positioned AP pelvis, the lesser trochanters should appear this way.
What is minimally visible or not visible
This is the difference between light and dark areas on an image.
What is contrast?
This shielding material is commonly used in aprons.
What is lead
This joint is visualized in a sunrise projection.
What is the patellofemoral joint?
This interaction causes ionization and is responsible for most patient dose.
What is the Compton effect?
In a lateral ankle, the talar domes are not superimposed. The correction is to adjust this.
What is rotation of the ankle/leg.
This factor primarily controls image density.
What is mAs?
This device measures occupational radiation exposure.
What is a dosimeter?
The scaphoid is best demonstrated with this positioning modification.
What is ulnar deviation.
The device that produces X-rays by accelerating electrons.
What is the X-ray tube
In an AP axial (Towne) projection, the dorsum sellae should project within this structure.
What is the foramen magnum.
Blur caused by motion is called this type of artifact.
What is motion blur?
The threshold dose concept is associated with this type of radiation effect.
What are deterministic effects.
This bone is commonly evaluated in a lateral skull radiograph.
What is the mandible?
This law states that intensity decreases with distance squared.
What is the inverse square law
Rotation in a PA chest is evaluated by comparing these structures relative to the vertebral column.
What are the sternoclavicular joints.
This improves contrast by absorbing scatter radiation.
What is a grid?
This organization sets radiation safety guidelines in the U.S.
What is the NCRP (National Council on Radiation Protection)
The CR for a PA axial Caldwell exits at this anatomical landmark.
What is the nasion.