Accession Number : ADA338745

Title :   Routine Quality Assurance for Whole Breast Digital Mammography.

Descriptive Note : Annual rept. 1 Sep 96-31 Aug 97,

Corporate Author : CALIFORNIA UNIV LOS ANGELES

Personal Author(s) : Kimme-Smith, Carolyn

PDF Url : ADA338745

Report Date : SEP 1997

Pagination or Media Count : 14

Abstract : Objectives: Methods are developed to establish minimum performance standards, calibration intervals, and criteria for exposure control for a whole breast digital mammography system. Methods: A prototype phantom was designed, and an automatic method programmed, to analyze SNR, resolution, and dynamic range between CCD components in the image receptor and over time. The phantom was imaged over a 5 month period and the results are analyzed to predict future performance. White field recalibration was analyzed by subtracting white fields obtained at different intervals. Exposure effects were compared using the prototype phantom for different kVp, filtration (Mo vs. Rh) and mAs. Results: Resolution tests, when Mo anode/Mo filter combinations are used will require daily phantom imaging. If Mo anode/RH filter techniques are used, weekly imaging will suffice. Differences between CCD performance are greater (1 2%) than differences in a single CCD over time (6%). White field recalibration is needed weekly because of artifacts, which occur if longer intervals between recalibration occur. Higher kVp and Rh filtration give markedly better phantom performance than Mo filtration at 26 kVp and are recommended for clinical exposures. Conclusions: Phantoms for digital mammography units should cover the entire image receptor, should test intersections between components of the receptor, and should be imaged more frequently than current recommendations for screen/film systems.

Descriptors :   *X RAYS, *QUALITY ASSURANCE, *PREVENTIVE MEDICINE, *MEDICAL EXAMINATION, *RADIOLOGICAL LABORATORIES, *MAMMOGRAPHY, EXPOSURE(GENERAL), ACOUSTIC IMAGES, LABORATORY PROCEDURES, LABORATORY EQUIPMENT, DYNAMIC RANGE, MAMMARY GLANDS, CLINICAL LABORATORIES.

Subject Categories : Anatomy and Physiology
      Medicine and Medical Research

Distribution Statement : APPROVED FOR PUBLIC RELEASE