Diagnostic Mammogram (both breasts)

What it is

Breast tissue varies enormously between women and hardly at all between one woman's two sides. That symmetry is a diagnostic tool in itself: a pattern that would look alarming in isolation is often reassuring once the same pattern turns up in the mirror-image position on the other side, and a density present on one side alone is worth pursuing even when it looks unremarkable. A bilateral diagnostic mammogram exploits that. It is the problem-solving kind of mammogram — extra angles, magnified views, spot compression, with a radiologist directing the study as it goes — applied to both breasts rather than one. Radiologists reach for the bilateral version when symptoms are on both sides, when a finding on one side needs the other as its reference, or when the full picture matters because of what is already known about this patient.

Why it is done

• To evaluate symptoms present in both breasts, or symptoms that are hard to localize to one side
• To compare an abnormal area against the matching position on the other side, which is often what settles whether it is real
• To work up a finding in a woman with no recent prior films of either breast to compare against
• To assess both breasts in someone with a personal history of breast cancer, where the treated side and the other side are both of interest
• To sort out an abnormality first reported on a screening study

What to expect

Skin should be free of deodorant, powder and lotion, since particles can mimic the tiny white flecks that are one of the things radiologists look for. Each breast is compressed on the plate for a few seconds per view, and because this is a directed study the number of views is decided as it goes rather than in advance. Expect longer than a screening appointment, and expect to wait between series while the radiologist reviews what has been taken. Additional ultrasound of one or both breasts is common in the same visit. Because a radiologist is on hand, results are often discussed before you go home, along with what is recommended next.

Questions worth asking

• Confirm the study is being coded as bilateral. A bilateral diagnostic mammogram is one code covering both sides, not two unilateral charges.
• Ask how your plan processes a diagnostic mammogram. Preventive screening coverage often does not extend to it, so a deductible may apply.
• Ask whether three-dimensional tomosynthesis views are included, since they are billed under their own separate code.
• Ask whether a follow-up interval study has already been recommended, and what that study will cost, before you leave the appointment.
• If a biopsy is recommended on the spot, ask for it to be priced separately rather than assuming it is covered by today's imaging estimate.