Factors affecting increasing radiation dose for mammography in North Carolina from 1997 through 2001: an analysis of Food and Drug Administration annual surveys.
OBJECTIVE
To determine which factors affected the increase in average glandular dose recorded at the annual US Food and Drug Administration Mammography Quality Standards Act inspections of mammography equipment in North Carolina from 1997 to 2001.


METHODS
Average glandular dose, HVL, kVp, ambient light, luminance, equipment age, processing speed, and system speed for every mammography unit at all facilities in the state were collected by state inspectors. A mixed-effect model was used to assess the average changes of glandular dose over time and to identify the factors associated with these changes.


RESULTS
There was a statistically significant increase in the average glandular dose in North Carolina in 1999, 2000, and 2001 when compared with the baseline year of 1997. Factors that were statistically significantly linked to this effect were changes in kVp, processing speed, and system speed.


CONCLUSIONS
Average glandular dose for mammography has recently increased in North Carolina. This change is likely caused by changes in screen-film products and processing techniques.
Pisano
Etta D
ED
Department of Radiology and Biostatistics, University of North Carolina Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, CB# 7510 Manning Dr, Chapel Hill, NC 27599-7510, USA. etpisano@med.unc.edu
Chiu
Yen-Feng
YF
Ni
Liyun
L
Li
Yun
Y
Britt
Gerald G
GG
Johnson
R Eugene
RE
Burns
Barry
B
Cole
Elodia
E
Kuzmiak
Cherie
C
Koomen
Marcia
M
Pavic
Dag
D
D000847:Annual Reports as Topic; D005260:Female; D019538:Health Care Surveys; D006801:Humans; D008327:Mammography / Q000295:instrumentation / Q000592:standards* / Q000639:trends*; D009010:Monte Carlo Method; D009657:North Carolina; D011786:Quality Control; D011829:Radiation Dosage; D014481:United States; D014486:United States Food and Drug Administration