E1798. A Tour of Breast Imaging Findings in the Lactating and Pregnant Patient
  1. Curtis Simmons; Mayo Clinic
  2. Laura Harper; Mayo Clinic
  3. Asha Bhatt; Mayo Clinic
Pregnant and lactating women represent the minority of patients presenting for breast imaging. This group of patients has an expanded differential from the majority of breast imaging patients and the American College of Radiology (ACR) has issued a separate appropriateness criteria specifically for these patients. Of concern to pregnant patients is the risk of radiation dose to the fetus. This is countered by the high relative risk of patients with BRCA1/BRCA2 who require screening mammography during childbearing years. The traditional 4 view mammogram has a negligible fetal dose and remains recommended for screening even in the setting of pregnancy. This differs from other screening methods such as Magnetic Resonance Imaging (MRI) and Molecular Breast Imaging (MBI). The MRI requires the use of contrast for enhancement kinetics. The gadolinium contrast crosses the placenta with uncertain consequences during fetal development. The risk of radiation is significantly higher with an MBI exam compared with a mammogram, with the Sestamibi causing the highest fetal radiation dose of available examinations. The changes that a breast undergoes during pregnancy and lactation are significant enough that a screening ultrasound is not recommended. The changes that a breast undergoes decrease the sensitivity and specificity of screening ultrasound. However, a diagnostic ultrasound in the setting of a palpable abnormality remains recommended. The recommendations for pregnant and lactating breasts likewise extends to the pediatric population with adolescents presenting with similar pathologies to adults in childbearing years.

Educational Goals / Teaching Points
• Review common conditions that are associated with pregnancy and lactation. • Understand available modalities that are available for diagnostic workup. • Review relative contraindication for workup in lactating and pregnant patients.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
The appearance of the breast differs substantially during pregnancy and lactation from the quiescent breast that is routinely seen in breast imaging. The presenting etiologies for pregnant and lactating patients are also expanded because of the physiological activity that the breast preforms.

The lactating and pregnant patient have physiologically active breasts which changes the appearance of the breast from routine studies seen in the reading room. Imaging of the pregnant and lactating patient requires an expanded differential from the traditional patient. Although the risk of radiation exposure should be at the forefront of concern with pregnancy, a traditional 4 view mammogram has a negligible dose and should not be avoided during workups for breast pathology. Many of the findings in pregnancy and lactation will overlap with breast presentations for older adolescents.