2338. Contrast Enhanced Mammography (CEM): Correlation of Enhancement with Low-Energy Findings as a Predictor of Breast Malignancy
Authors * Denotes Presenting Author
  1. Geunwon Kim *; Beth Israel Deaconess Medical Center
  2. Tejas Mehta; Beth Israel Deaconess Medical Center
  3. Rashmi Mehta; Beth Israel Deaconess Medical Center
  4. Valerie Fein-Zachary; Beth Israel Deaconess Medical Center
  5. Vandana Dialani; Beth Israel Deaconess Medical Center
  6. Linda Du; Beth Israel Deaconess Medical Center
  7. Jordana Phillips; Beth Israel Deaconess Medical Center
Despite the increased use of contrast-enhanced mammography (CEM) in clinical practice, there remains little data on how enhancement impacts the probability of malignancy of low-energy findings. Our purpose is to determine outcomes of low-energy findings as they relate to enhancement

Materials and Methods:
All CEM cases performed at our institution from December 18, 2014 to December 5, 2019 were reviewed. Information for each CEM finding was recorded to include low-energy and recombined imaging features, BI-RADS, and outcome as determined by pathology or 1-year imaging/clinical follow-up. Cases without pathology or 1-year follow-up were excluded.

279 low-energy findings were seen in 451 CEM exams of which 70/279 (25%) were calcifications, 171/279 (61%) were masses, 29/276 (11%) were architectural distortion (AD), and 9/279 (3%) were asymmetries. Enhancement was seen in 28/70 (40%) calcifications, 131/171 (77%) masses, 23/29 (79%) AD, and 4/9 (44%) asymmetries. 24/28 (86%) of enhancing calcifications and 6/42 (14%) of non-enhancing calcifications were malignant. 66/131 (50%) of enhancing masses and 0/40 of non-enhancing masses were malignant. 11/23 (48%) of enhancing AD and 0/6 of non-enhancing AD were malignant. 1/4 (25%) of enhancing and 0/5 non-enhancing asymmetries were malignant. Sensitivity and specificity were 80% and 90% (calcifications), 100% and 38% (masses), and 100% and 33% (AD). PPV and NPV were 86% and 86% (calcifications), 50% and 100% (masses), and 48% and 100% (AD). Enhancement was associated with malignant calcifications, masses, and AD (p<0.0001, p<0.0001, and p=0.0315, respectively). Asymmetries were not included in analysis due to low sample size.

Enhancing calcifications, masses, and AD are more often malignant than their non-enhancing counterparts. While non-enhancing masses and AD are unlikely to be malignant, malignancy cannot be excluded in non-enhancing calcifications.