Prog Med Phys.  2014 Dec;25(4):271-280. 10.14316/pmp.2014.25.4.271.

A Study of Various Filter Setups with FBP Reconstruction for Digital Breast Tomosynthesis

• Lee HH
• Kim YS
• Lee Y
• Choi S
• Lee S
• Park HS
• Kim HJ
• Choi JG
• Choi YW

• KMID: 2315767
• DOI: http://doi.org/10.14316/pmp.2014.25.4.271

Abstract

Recently, digital breast tomosynthesis (DBT) has been investigated to overcome the limitation of conventional mammography for overlapping anatomical structures and high patient dose with cone-beam computed tomography (CBCT). However incomplete sampling due to limited angle leads to interference on the neighboring slices. Many studies have investigated to reduce artifacts such as interference. Moreover, appropriate filters for tomosynthesis have been researched to solve artifacts resulted from incomplete sampling. The primary purpose of this study is finding appropriate filter scheme with FBP reconstruction for DBT system to reduce artifacts. In this study, we investigated characteristics of various filter schemes with simulation and prototype digital breast tomosynthesis under same acquisition parameters and conditions. We evaluated artifacts and noise with profiles and COV (coefficinet of variation) to study characteristic of filter. As a result, the noise with parameter 0.25 of Spectral filter reduced by 10% in comparison to that with only Ramp-lak filter. Because unbalance of information reduced with decreasing B of Slice thickness filter, artifacts caused by incomplete sampling reduced. In conclusion, we confirmed basic characteristics of filter operations and improvement of image quality by appropriate filter scheme. The results of this study can be utilized as base in research and development of DBT system by providing information that is about noise and artifacts depend on various filter schemes.

Keyword

Digital breast tomosynthesis; FBP reconstruction; Spectral filter; Slice thickness filter; Noise; Interference

MeSH Terms

Artifacts
Breast*
Cone-Beam Computed Tomography
Humans
Mammography
Noise

Figure

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  Fig. 1. (a) Photo and (b) schematic illustration of digital breast tomosynthesis system.

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  Fig. 2. (a) A schematic illustration of simulated phantom and (b) in-plane and out-of plane of ball phantom.

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  Fig. 3. (a) Sampled region in the frequency domain by the Fourier slice theorem, and (b) a schematic illustration of slice thickness filter in z-direction frequency that can be used to improve artifacts resulted from missing data.

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  Fig. 4. Reconstructed images of ball phantom with filter scheme (a) 1, (b) 2, (c) 3, and (d) 4.

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  Fig. 5. Profiles through line #25 of reconstructed slice #25 with different spectral filters.

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  Fig. 6. Reconstructed images of ball phantom with filter scheme (a) 5, (b) 6, (c) 7, and (d) 8. The in-plane slices through the balls center, and the out-of-planes with distance of 8 mm were shown.

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  Fig. 7. Profiles through line #25 of reconstructed slice #25 and #33 with filter scheme (a) 5, (b) 6, (c) 7, and (d) 8. The normalized profiles in the slice #25 through the object (z=0) were drawn with black lines, the profiles for the slice #33 (Z=8 mm) with red lines.

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  Fig. 8. Central slices of breast phantom reconstructed with filter scheme (a) 1, (b) 2, (c) 3, and (d) 4.

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  Fig. 9. The reconstructed images of breast phantom. The in-planes (slice #17) reconstructed with filter scheme (a) 5, (c) 6, (e) 7, and (g) 8. The out-of-planes (slice #25) reconstructed with filter scheme (b) 5, (d) 6, (f) 7, and (h) 8.

Reference

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