The most accessible breast imaging modalities are conventional and digital mammography, MRI, ultrasound, and nuclear medicine. Let's consider each of them.

Conventional screen-film mammography has been considered for over 35 years to be the gold standard for screening breasts for early signs of breast cancer. It is a well-known and accepted fact that imaging dense breast tissue with screen-film is a challenge. Many improvements have been made in image quality with digital mammography. The Digital Mammographic Imaging Screening Trial (DMIST) sponsored by the National Cancer Institute has found that the accuracy of digital mammography was significantly higher than that of film mammography among women under the age of 50 years with heterogeneously dense or extremely dense breasts on mammography and premenopausal or perimenopausal women. An abstract of the full study may be downloaded for free from the New England Journal of Medicine Web site.

Magnetic Resonance Imaging (MRI) of the breasts has increased sensitivity in finding early breast cancer in young women due to its ability to detect lesions without calcium even in dense breasts. MRI is limited in that it cannot demonstrate microcalcifications as mammography can, finding only about half as many as those detected by mammography. It has been found by clinicians that combining MRI with digital mammography improves the detection rate for high-risk patients and those with dense breasts.

Similarly, ultrasound is typically performed in conjunction with mammography for those palpable masses that are not visualized in women with dense breast tissue.

Positron Emission Tomography (PET), Positron Emission Mammography (PEM) and Single-Photon Emission Computed Tomography (SPECT) are non-invasive nuclear medicine imaging examinations well accepted for their ability to stage cancer growth and monitor treatment of such, rather than be used for initial diagnosis. If not for cost, more clinicians might consider PEM examinations in place of breast biopsies due to its ability to differentiate between a malignant and benign tumor, as well as indicate metastases.

Imaging breast tissue through radiographic means is currently the best choice for women in the early detection of breast cancer. Those clinical situations that arise when the breast tissue is too dense to penetrate well with mammography, combining MRI or ultrasound is the best way to evaluate her breast health.