Mammography in the 1990s: The United States and Canada

Abstract

To evaluate trends in mammography quality before and after the implementation of the Mammography Quality Standards Act (MQSA) of 1992 and to compare technical data collected in the United States with corresponding data obtained from the first survey of mammography facilities conducted in 1994-1995 in Canada. Data from MQSA inspections conducted in 1995-1997 were analyzed and compared with survey data on U.S. mammography facilities acquired before the MQSA. Technical indicators of mammography quality such as radiation dose phantom image score, film processing, and darkroom fog were analyzed. In the United States, phantom image scores, along with other technical measures of performance such as film processing, darkroom fog, and x-ray beam quality, have improved continuously since 1985. The U.S. mean glandular dose has increased to 1.6 mGy compared with the Canadian dose of 1.1 mGy. The mean total phantom image score with artifact subtraction was 11.1 in Canada in 1994-1995 and 11.8 in the U.S. in 1997. Mammography quality is better today than it has been at any other time in the United States. With the exception of radiation dose. Canadian technical measures of performance are comparable to measures before MQSA in the United States.