Why do i need mammogram and a breast ultrasound?

Both are helpful: Mammograms use x-ray technique and are better at detecting tiny calcium deposits that may signal an early breast cancer than ultrasound. Mammograms can also detect tumors. Ultrasound uses soundwaves, like sonar, and will help determine if a lump is solid (requiring biopsy) or a cyst (fluid filled & usually not cancer). Both tests work together to find breast cancer.

Possibilities?: A breast ultrasound may be requested to evaluate a specific abnormality on mammogram, acomplaint you may have in a specific area of the breast, or an area that is felt on examination but either not seen on mammogram, or not seen well on mammogram.

You have to: ask your doctor. There are a number of possibilities why both were ordered. Did your doctor feel a lump? Was there an abnormality on screening mammo requiring extra views and ultrasound? Do you have dense breasts and adjunct ultrasound screening was felt to be warranted?