The usefulness of mammography is dependent on the proper use of dedicated mammography equipment, the diagnostic skills of the interpreter, and assessing and diminishing barriers to its regular use. These issues have been and are currently being addressed in an effort to promote safe and effective mass screening for early-stage breast cancer.

As knowledge and use of mammography slowly increased after the beginning of early promotion efforts, the Nationwide Evaluation of X-Ray Trends demonstrated a great variation in dose and image quality among mammography sites. This report emerged at the time that the ACS was initiating its National Breast Cancer Awareness Screening Program.

Troubled by the Nationwide Evaluation of X-Ray Trends report and hoping to alleviate the problems it identified, the ACS approached the ACR to stimulate the development of quality standards for mammography facilities. With funding from the ACS, the voluntary ACR Mammography Accreditation Program was established and began to accredit mammography facilities in August 1987. The application process included a questionnaire to obtain information about personnel, volume, and type of examinations performed; the imaging system through evaluation of phantom images and dose delivery; and, most important, assessment of clinical images to evaluate positioning, contrast, compression, and image-label identifiers.

The process of clinical image evaluation was performed by a group of radiologists with extensive experience in mammography who were trained to identify problems in clinical images that would hinder or prevent identification of early breast cancer. Evaluation of the image processing was later added when it was learned that many problems identified by clinical image review could be traced to faulty processor performance. Over time, greater understanding of the link between high-quality mammography and the goals of breast cancer screening led to new regulatory initiatives.

Maryland was the first state to pass legislation pertaining to quality assurance in mammography. In 1986, legislation was passed that required mammography examinations to be performed with machinery designed and built only for mammography. These dedicated units were vastly superior to mammography performed on general purpose machines in terms of dose and image quality. By 1993, 41 states and the District of Columbia had either passed legislation or established regulations addressing quality mammography.

Toward the end of 1990, Congress added mammography to the benefit package for Medicare-eligible women and included quality standards for sites approved to provide services to Medicare beneficiaries. These standards were heavily influenced by the ACR Mammography Accreditation Program standards. Also in that year, Congress passed the Breast and Cervical Cancer Mortality Prevention Act of 1990 (PL 101-354), appropriating funds to the CDC for state programs to provide breast and cervical cancer screening to low-income women. Recognizing the importance of high-quality mammography, the CDC required facilities that provided services under this program to be certified by the Health Insurance Financing Administration and to have ACR accreditation. By this time, a mammography facility could have been operating under a state standard, a federal standard, and a voluntary standard, each of which could vary on important criteria related to quality.

On the other hand, a facility might have operated with little or no oversight, because ACR accreditation was voluntary, and the facility might choose not to offer screening to Medicare beneficiaries or to participate in the CDC program. Although a majority of states had regulations governing mammography quality assurance, state oversight was inconsistent at best. Thus, even with the emergence of new quality-oriented programs, the majority of facilities still had uneven adherence to quality standards. In order to ensure that women could depend on a uniform set of quality standards in all mammography facilities, in 1992 Congress passed the Mammography Quality Standards Act (MQSA), which was signed by President George Bush in October of that year. Under MQSA, all facilities offering mammography services would be required to be accredited by a private accrediting body, undergo an annual on-site inspection, and be certified by an agency designated by the Secretary of Health and Human Services.