Physicians order mammograms to detect or diagnose breast abnormalities ranging from cysts to cancer. Mammograms may be performed for different purposes and include:

• Screening mammogram. Used when women have no signs or symptoms of breast cancer. The goal is to detect cancers in the earliest state. A screening mammogram typically requires two x-rays of each breast.
  
  
• Cranial-caudal. Examines the breasts from above.
  
  
• Mediolateral-oblique. Examines the breasts from an angle that includes breast tissue extending to the armpit.
  
  
The initial mammogram is often called the baseline mammogram. Radiologists use this image as a baseline against which they will compare future mammograms.


• Diagnostic mammogram. Used to check for cancer due to symptoms or other test results, including screening mammograms. Diagnostic mammograms may include more images and may concentrate on specific areas of the breast. Changes in the breast that may indicate the need for a mammogram include:
  
  
• Lumps
• Pain
• Nipple thickening, retraction or discharge
• Change in breast size or shape, or change in overlying skin
  
  
• After a woman has been diagnosed with breast cancer, she will continue to receive regular diagnostic mammograms.
  
  Diagnostic mammograms are also used to evaluate the breasts of women with implants, which sometimes can obscure the presence of the disease.