Best adjunct to mammography in diagnostic work up of breast masses.
Best guidance technique for percutaneous biopsy of breast masses.
Has a high detection rate for breast masses.
Fails to detect microcalcifications and not used to detect ductal carcinoma in situ but is used for staging invasive breast cancer.
Superior to mammogram in measuring actual,size of breast cancers in dense breasts.
Accuracy of US depends on demarcation of boundaries between the tumor and surrounding tissues, shape of mass, and shape of tumor mass.
In most cases breast US can provide a precise T stage.
Poorly defined masses are poorly measured
Lesions such as invasive lobular carcinoma which often appears flat with little or no circumscribed mass and is difficult to find or measure..