RFA - procedural/coding question

Let’s say I knew someone who billed 64635 and 64636 and only used two needles to perform that injection (needles placed at L4MB and L5DR). Is there a textbook or article someone could direct me to that outlines how that procedure should actually require 3 needles? The cms guidelines for RFA speak on billing levels, but not needles required to treat said levels. I looked in my rothman text and found nothing, and don’t see anything on google.
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Tags: Pain Medicine Source Type: forums