Question:
Can you provide a definition for “digitally subtract” when it comes to imaging? And does this procedure have an impact on code assignments?
Answer:
Digital subtraction is an imaging technique that has no impact on coding. Many years ago there was a code for subtraction but that was when this was done in a darkroom and required much work. Now it is all done digitally with a few clicks. (For more, see https://en.wikipedia.org/wiki/Digital_subtraction_angiography.)