BIRADS IIIA and IIIB: Follow for 2 years (6 months, 1 year, 2 year), whereas mammo every 3 years; 24% of 1st time MRI given BI-RADS III; 0%â10% cancer rate (3% MSKCC: small invasive cancers, and DCIS)
It is important to remember that, as most MRIs of the breast are performed on high risk population, 17% of smooth masses on the first Â MRI were cancer.
Clinical history and correlation with mammography is always useful and can reduce assignment of BIRADS III category.
Positive predictive value higher the closer the lesion is to the index cancer.
Biopsy to get histological diagnosis no matter how suspicious because result is Mx.
Indications for breast MRI per ACR guidelines.
Indications for breast MRI per ACS.
MRI features and PPV.
Caveat: if mammography or ultrasound is positive or palpable finding need to treat/biopsy/excise despite negative MRI.