Position : use this when indicating the patient’s general physical position such as supine, prone, etc. It is also used to describe specific body positions such as obliques and laterals. Restrict the use of this word to the patient’s physical position.
Projection : describes the path or direction of the central ray; restrict the use of this word to the CR
View : not a correct positioning term in the US; restrict the use of the word view to describing the image from the vantage of the image receptor
Principle for Determining Positioning Routines
A minimum of two projections (90 degrees from each other) is required for most procedures. Why? Because:
Certain conditions may not be visualized on one projection only
Sometimes foreign bodies are embedded and two projections are needed to determine exact location
All fractures require two projections at 90 degree angles to determine alignment of the fracture parts
A minimum of three projections when joints are in interest area. Why? Because more information is needed than can be provided by two projections. See list in book on page 37 to determine which procedures require two projections and which require three.