I'm new to urology coding and am having a hard time understanding the difference between these two codes. I understand that the 52000 is just the cystourethroscopy by itself, and the 52281 is "cystourethroscopy, with calibration and/or dilation of urethral stricture or stenosis" but what I'm having a hard time understanding is what exactly "sounding" is. In alot of the doctor's op notes he says "cystourethroscopy with sounding" where he inserts a french #21, for example, and then states that he went up to a french #26 with no problem. In most if not all of the cases there is no stenosis and there's no mention of stenosis or stricture, he's just inserting a larger cystoscope. The person who was coding these before me was coding them as a 52281 because he was technically "dilating" the urethra, but the rest of the description doesn't fit (the lay description). Why would sounding be done with a cystosope, and is that considered "dilation"? At least enough to qualify for the 52281? 
Example: "A #21 French ACMI cystoscope with Foroblique lens was through the urethra and into the bladder. The urethra was sounded to #26 French with no obstruction. The bladder was entered and examined and there was a mild increased pattern of vascularity consistent with a low-grade cystitis."
The preoperative dx was urge incontinence & post op was mild cystitis and urge incontinence. Would this be a 52000 or 52281? Any help I could get would be greatly appreciated!
Example: "A #21 French ACMI cystoscope with Foroblique lens was through the urethra and into the bladder. The urethra was sounded to #26 French with no obstruction. The bladder was entered and examined and there was a mild increased pattern of vascularity consistent with a low-grade cystitis."
The preoperative dx was urge incontinence & post op was mild cystitis and urge incontinence. Would this be a 52000 or 52281? Any help I could get would be greatly appreciated!