[Estimation of glandular content rate and statistical analysis of the influence of age group and compressed breast thickness on the estimated value].
Because the glandular content rate is an important factor in evaluating breast cancer detection and average glandular dose, it is important in mammography research to estimate and analyze this rate. The purpose of this study was to obtain a formula for statistical estimation of the glandular content rate, to clarify statistically the influence of age group and compressed breast thickness (CBT) on estimating the glandular content rate, and to show statistically the general relation between glandular content rate and the factors of age and CBT. The subjects were 740 Japanese women aged 20-91 years (mean+/-SD: 48.3+/-12.8 years) who had undergone mammography. In our study, the glandular content rate was statistically estimated from age group, mAs-value, and CBT when subjects underwent mammography, from a phantom simulation, and from MR images of the breast. In addition, multivariate analysis was carried to examine statistically the influence of age group and CBT on glandular content rate. The mean glandular content rate as estimated by age group was as follows: 35.6% for those in their 20s, 33.4% in the 30s, 27.5% in the 40s, 23.8% in the 50s, and 21.8% in those 60 and over. The rate for the subjects as a whole was 27.1%. This study indicated that overestimation occurred if the estimated value of the glandular content rate was not corrected in the 3D-measurement by MRI. In addition, this study showed that the statistical influence on glandular content rate was significantly larger for CBT than age.
Ohmori
Naoki
N
Department of Radiology, Osaka Medical College Hospital.
Ashida
Kenji
K
Fujita
Osamu
O
D000328:Adult; D000367:Age Factors; D000368:Aged; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000175:diagnosis / Q000473:pathology; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D015999:Multivariate Analysis; D019047:Phantoms, Imaging; D011312:Pressure