mammography coding

I have a patient who has a known cyst in one breast when she went in to her well woman exam the doctor billed a bilateral diagnostic mamm with 611.72. Her insurance applied the allowable to deductible. Is there a way to bill 1 unilateral screening mam with modifier RT and 1 unilateral diagnostic mamm with modifier LT?? If so can you help me identify the correct CPT® codes?

Thanks,
Tracy