Which imaging modality is commonly used to evaluate a lesion seen on mammography in dense breasts?

• A. Ultrasound
• B. MRI
• C. CT
• D. PET

Answer: (A)

Dense breast tissue makes it harder for mammography to distinguish lesions, since both dense tissue and many cancers appear white on the image. When a lesion is seen on mammography in dense breasts, ultrasound is commonly used to evaluate it further.

Ultrasound uses sound waves, so its assessment isn’t hindered by density. It helps determine whether the finding is solid or cystic, describes margins and internal structure, and can assess vascularity with Doppler. This information is crucial for distinguishing likely benign from suspicious lesions and for guiding biopsy if needed. Ultrasound is quick, widely available, cost-effective, and does not involve ionizing radiation, making it a practical adjunct to mammography in this setting.

MRI, while very sensitive, is typically reserved for problem-solving or high-risk screening due to cost and availability. CT and PET are not standard choices for evaluating a mammographic lesion in dense breasts because they offer less breast-specific detail (and involve radiation in CT) or provide functional metabolic information rather than lesion characterization.