Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2013 Oct;40(10):101905.
doi: 10.1118/1.4820442.

Power spectrum analysis of the x-ray scatter signal in mammography and breast tomosynthesis projections

Ioannis Sechopoulos  1 , Kristina Bliznakova, Baowei Fei
Affiliations

Power spectrum analysis of the x-ray scatter signal in mammography and breast tomosynthesis projections

Ioannis Sechopoulos et al. Med Phys. 2013 Oct.

Abstract

Purpose: To analyze the frequency domain characteristics of the signal in mammography images and breast tomosynthesis projections with patient tissue texture due to detected scattered x-rays.

Methods: Acquisitions of x-ray projection images of 19 different patient breasts were simulated using previously acquired volumetric patient images. Acquisition of these images was performed with a dedicated breast CT prototype system, and the images were classified into voxels representing skin, adipose, and glandular tissue with a previously validated automated algorithm. The classified three dimensional images then underwent simulated mechanical compression representing that which is performed during acquisition of mammography and breast tomosynthesis images. The acquisition of projection images of each patient breast was simulated using Monte Carlo methods with each simulation resulting in two images: one of the primary (non-scattered) signal and one of the scatter signal. To analyze the scatter signal for both mammography and breast tomosynthesis, two projections images of each patient breast were simulated, one with the x-ray source positioned at 0° (mammography and central tomosynthesis projection) and at 30° (wide tomosynthesis projection). The noise power spectra (NPS) for both the scatter signal alone and the total signal (primary + scatter) for all images were obtained and the combined results of all patients analyzed. The total NPS was fit to the expected power-law relationship NPS(f) = k/f β and the results were compared with those previously published on the power spectrum characteristics of mammographic texture. The scatter signal alone was analyzed qualitatively and a power-law fit was also performed.

Results: The mammography and tomosynthesis projections of three patient breasts were too small to analyze, so a total of 16 patient breasts were analyzed. The values of β for the total signal of the 0° projections agreed well with previously published results. As expected, the scatter power spectrum reflected a fast drop-off with increasing spatial frequency, with a reduction of four orders of magnitude by 0.1 lp/mm. The β values for the scatter signal were 6.14 and 6.39 for the 0° and 30° projections, respectively.

Conclusions: Although the low-frequency characteristics of scatter in mammography and breast tomosynthesis were known, a quantitative analysis of the frequency domain characteristics of this signal was needed in order to optimize previously proposed software-based x-ray scatter reduction algorithms for these imaging modalities.

PubMed Disclaimer

Figures

Figure 1
Figure 1
(a) Power spectra of the total (primary + scatter) signal for all 16 patients studied (symbols) and the result of averaging across all patients (line). (b) Average across all patients of the total power spectra for the 0° and 30° projections. All power spectra are before division by the sinc function.
Figure 2
Figure 2
Power law fit for the 0° and 30° total power spectra after division by the sinc function of the pixel aperture.
Figure 3
Figure 3
(a) Power spectra of the scatter signal for all 16 patients studied (symbols) and the result of averaging across all patients (line). (b) Average across all patients of the scatter power spectra for the 0° and 30° projections. All power spectra are before division by the sinc function.
Figure 4
Figure 4
Power law fit for the 0° and 30° scatter power spectra after division by the sinc function of the pixel aperture.
Figure 5
Figure 5
Power spectrum averaged for all patients and divided by the square of the sinc function of the pixel aperture, for the 0° projection for both the scatter only and the total signal. The difference in spatial frequency components of the two signals is evident in this plot.
See this image and copyright information in PMC

References

    1. Liu B., Wu T., Moore R. H., and Kopans D. B., “Monte Carlo simulation of x-ray scatter based on patient model from digital breast tomosynthesis,” Proc. SPIE 6142, 61421N–61429N (2006).10.1117/12.650193 - DOI
    1. Wu G., Mainprize J. G., Boone J. M., and Yaffe M. J., “Evaluation of scatter effects on image quality for breast tomosynthesis,” Proc. SPIE 6510, 65101T–65109T (2007).10.1117/12.708531 - DOI - PMC - PubMed
    1. Wu G., Mainprize J. G., Boone J. M., and Yaffe M. J., “Evaluation of scatter effects on image quality for breast tomosynthesis,” Med. Phys. 36, 4425–4432 (2009).10.1118/1.3215926 - DOI - PMC - PubMed
    1. Hogge J. P., Palmer C. H., Muller C. C., Little S. T., Smith D. C., Fatouros P. P., and de Paredes E. S., “Quality assurance in mammography: Artifact analysis,” Radiographics 19, 503–522 (1999). - PubMed
    1. Sechopoulos I., “A review of breast tomosynthesis. Part I. The image acquisition process,” Med. Phys. 40, 014301 (12pp.) (2013).10.1118/1.4770279 - DOI - PMC - PubMed

Publication types