MRI vs US give opposite results. which is more accurate?

39/f here. high lifetime risk @ 35.8%. Also my career is in radiology, so I understand the lingo, but just not such differing results.

had breast MRI to supplement a negative annual screening mammo. results were 4mm focus of enhancement WITH washout kinetics. which is highly suggestive of malignancy.

2 weeks later i get the recommended followup US. those results were 5mm oval hypoechoic mass, which is most likely benign.

is it common to have opposing results like this? it was recommended for a 6 month followup US, which will be due this Nov. so a definitive answer is still pending. should i push for biopsy anyways with lifetime risk being high?

Comments

  • moderators
    moderators Posts: 8,498

    Hi @radiologylady, and welcome to BCO. You likely know more since you are in the field, but yes, each diagnostic test works completely differently.

    Breast MRI (magnetic resonance imaging) uses magnets and radio waves to produce detailed 3D images of the breast tissue. Breast MRI can find some breast cancers that would not be detected on a mammogram, particularly in women with dense breast tissue. When breast MRI is used for breast cancer screening, it’s usually used in addition to — not instead of — a mammogram.

    https://www.breastcancer.org/screening-testing/breast-mri

    A breast ultrasound (also called sonography) is an imaging test that sends sound waves through your breast to create a digital image of the inside of the breast. Breast ultrasound alone cannot be used to diagnose breast cancer. Other tests — including a breast biopsy — are always needed to make a diagnosis.    

    https://www.breastcancer.org/screening-testing/ultrasound

    Read here about Screening and Testing:

    https://www.breastcancer.org/screening-testing

    So, yes, certain tests will likely yield different information, and a breast biopsy is the only test that can tell for sure if an area of concern — for example, a spot flagged on a mammogram or US— is cancer.

    We hope this is helpful! Keep advocating for yourself ❤️

  • vlnrph
    vlnrph Member Posts: 508

    Sorry you are stuck with figuring out these seemingly discrepant imaging results. As you know, MRI is sensitive but not specific. That means it can see lots of things however defining them is more difficult. I think 4-5 mm lesions are probably too small to biopsy.

    If your upcoming ultrasound is equivocal, would a follow-up PET be possible? Again, tiny tumors may not be big enough to show up. Ask whether a scan like that now could provide a baseline for the future. They are expensive so prior authorization might be denied.

    Perhaps breast density is a concern. Also, keep in mind that lobular cancer is notoriously hard to detect. I kept getting called back for “architectural distortion” evaluation especially when film mammography was used. Even with digital data, mine didn’t get diagnosed for years…

  • radiologylady
    radiologylady Member Posts: 2

    @vlnrph wow you have been through the ringer with all that!! You are a warrior!

    And yes, the biggest problem is dense breast tissue for me. But PET scan wouldn't be an option at this point. It's not really used as a screening tool......yet! PET scans come in after a cancer diagnosis, mostly for staging I believe. Or during treatment.

    Ill just have to wait and see at my 6 month follow-up in November!