Radiology, Vol 184, 45-48, Copyright © 1992 by Radiological Society of North America
Mammographic unit compression force: acceptance test and quality control protocols
RL Tanner
Department of Radiology, University of Tennessee, Memphis 38163.
Firm compression of the breast in screen-film mammography procedures lowers
the radiation dose to patients, enhances image contrast and definition, and
improves visibility of pathologic conditions. Most mammography unit
compression systems have no force-level indicator. Some systems show force
variations with time and others, with angle and region of the compression
device. Still other systems give poorly reproducible compression-force
levels, and in one unit the force release mechanism jammed repeatedly.
Detailed procedures for initial acceptance testing and continuing quality
control checks are listed. Recommended measurements include levels of
manual and automatic applied force, stability, reproducibility, and
dependence on angulation and breast size and evaluation of operation of
release mechanisms. Also necessary are observations of the condition and
operation of the compression system. Test equipment is described and
measurement frequency is specified, as well as suggested tolerance limits.
Manufacturers of mammographic units are urged to build in compression-
force gauges and to provide both a manual mode and a variable-force
automatic mode.
