Background: Breast is one of the main
radiological sensitive organs, hence it is important to
evaluate absorbed dose to this organ especially to
the glandular parts. It is the aim of this study to
measure mean glandular dose and image contrast in
terms of different mammographic parameters.
Materials and Methods: In this study two
mammography machines located at Said-al Shohada
(Giotto) and Shahid Behesti (GE) hospitals were
used. According to the recommendations of ACR and
MQSA, breast phantoms were constructed and used
for this study. For dose evaluation TLD dosimetry
method was used. The TLD dosimeters were of LiF
type and the reader was a Solaro TLD reader.
Results: To obtain a constant contrast when
increasing kVp from 22 to 24, it was necessary to
reduce mAs by 12 percent. The obtained relation
between these two parameters is:
contrast=0.2829D-0.2427. It was also found that
there is a linear relationship between contrast and
image quality. The relation between these two
parameters is: Image quality = 28.117 Contarst +
20.134. Increasing kVp and hence decreasing mAs
results a reduction to the glandular dose, especially
in patients with large breast. Increasing kVp from 28
to 30 results in reduction of dose from 6.8mGy to
5mGy. Conclusions: It was found that there has been
a linear relationship between contrast and image
quality. It was also found that increasing kVp
necessitate to reduce mAs for a constant contrast
and hence reduction of glandular dose.
Tavakoli M, Kolghi N, Shahi Z, Shaneh Z. Evaluation of the relation between breast glandular absorbed dose and radiographic quality in mammography. Int J Radiat Res 2008; 6 (2) :77-82 URL: http://ijrr.com/article-1-407-en.html