Factors affecting increasing radiation dose for mammography in North Carolina from 1997 through 2001

Pisano, Etta D.; Chiu, Yen Feng; Ni, Liyun; Li, Yun; Britt, Gerald G.; Johnson, Rachel; Burns, Barry; Cole, Elodia B.; Kuzmiak, Cherie M.; Koomen, Marcia; Pavić, Dag

doi:10.1016/j.acra.2004.01.003

Cited by 7 publications

(1 citation statement)

References 35 publications

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“…The dotted lines demonstrate the fit values for 25% and 75% glandular breasts ͑bottom to top͒. The measured mammography dose levels are very consistent with those reported by other authors, 9 and even in the era of mammography "dose creep," 10 the mean glandular dose for a single view mammogram of a 4.5 cm 50%/50% breast was 2.16 mGy. Figure 5 illustrates the relationship between the breast diameter and the compressed breast thickness, based upon measured data from 200 women undergoing routine annual screening mammography.…”

Section: Resultssupporting

confidence: 88%

Technique factors and their relationship to radiation dose in pendant geometry breast CT

et al. 2005

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The use of breast computed tomography (CT) as an alternative to mammography in some patients is being studied at several institutions. However, the radiation dosimetry issues associated with breast CT are markedly different than in the case of mammography. In this study, the spectral properties of an operational breast CT scanner were characterized both by physical measurement and computer modeling of the kVp-dependent spectra, from 40 to 110 kVp (Be window W anode with 0.30 mm added Cu filtration). Previously reported conversion factors, normalized glandular dose for CT-DgN(ct), derived from Monte Carlo methods, were used in concert with the output spectra of the breast scanner to compute the mean glandular dose to the breast based upon different combinations of x-ray technique factors (kVp and mAs). The mean glandular dose (MGD) was measured as a function of the compressed breast thickness (2-8 cm) and three different breast compositions (0%, 50%, and 100% glandular fractions) in four clinical mammography systems in our institution. The average MGD from these four systems was used to compute the technique factors for breast CT systems that would match the two-view mammographic dose levels. For a 14 cm diameter breast (equivalent to a 5 cm thick compressed breast in mammography), air kerma levels at the breast CT scanner's isocenter (468 mm from the source) of 4.4, 6.4, and 9.0 mGy were found to deliver equivalent mammography doses for 0%, 50%, and 100% glandular breasts (respectively) at 80 kVp. At 80 kVp (where air kerma was 11.3 mGy/100 mAs at the isocenter), 57 mAs (integrated over the entire scan) was required to match the mammography dose for a 14 cm 50% glandular breast. At 50 kVp, 360 mAs is required to match mammographic dose levels. Tables are provided for both air kerma at the isocenter and mAs for 0%, 50%, and 100% glandular breasts. Other issues that impact breast CT technique factors are also discussed.

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Section: Resultssupporting

confidence: 88%