How do mammography and breast ultrasound differ, and can one replace the other?
Mammography uses low-dose X-rays, while breast ultrasound uses sound waves. They have different roles and may be requested together. Ultrasound helps assess some lumps but is not a general replacement for mammography, which may show changes that ultrasound misses.
Details
When does ultrasound help?
It may distinguish a fluid-filled cyst from a solid mass, assess a particular area or guide a biopsy. It does not detect every calcification or cancer, so a normal result alone cannot explain away a persistent symptom.
Why might more imaging be needed?
Age, symptoms, breast density, examination findings and individual risk guide selection. Dense breasts do not automatically mean every woman needs every imaging test. A clinician should explain the expected value and possible further investigations.
Before your appointment
Report possible pregnancy, breastfeeding and previous operations, and bring earlier images for comparison. Do not cancel indicated imaging because of pregnancy without discussing it; the team chooses an appropriate method for the clinical need. Concerning findings may still require a biopsy.
Related reading: When should I start mammograms, and how often should I repeat them?.