Attenuation coefficient in the energy range 14–36 keV of 3D printing materials for physical breast phantoms

Abstract

Objective To measure the monoenergetic x-ray linear attenuation coefficient, μ, of fused deposition modeling (FDM) colored 3D printing materials (ABS, PLAwhite, PLAorange, PET and NYLON), used as adipose, glandular or skin tissue substitutes for manufacturing physical breast phantoms. Approach Attenuation data (at 14, 18, 20, 24, 28, 30 and 36 keV) were acquired at Elettra synchrotron radiation facility, with step-wedge objects, using the Lambert-Beer law and a CCD imaging detector. Test objects were 3D printed using the Ultimaker 3 FDM printer. PMMA, Nylon-6 and high-density polyethylene step objects were also investigated for the validation of the proposed methodology. Printing uniformity was assessed via monoenergetic and polyenergetic imaging (32 kV, W/Rh). Main results Maximum absolute deviation of μ for PMMA, Nylon-6 and HD-PE was 5.0%, with reference to literature data. For ABS and NYLON, μ differed by less than 6.1% and 7.1% from that of adipose tissue, respectively; for PET and PLAorange the difference was less than 11.3% and 6.3% from glandular tissue, respectively. PLAorange is a good substitute of skin (differences from -9.4% to +1.2%). Hence, ABS and NYLON filaments are suitable adipose tissue substitutes, while PET and PLAorange mimick the glandular tissue. PLAwhite could be printed at less than 100% infill density for matching the attenuation of glandular tissue, using the measured density calibration curve. The printing mesh was observed for sample thicknesses less than 60 mm, imaged in the direction normal to the printing layers. Printing dimensional repeatability and reproducibility was less 1%. Significance For the first time was provided a first experimental determination of common 3D printing filament material for estimating μ at all energies in the range 14–36 keV, for their use in mammography, breast tomosynthesis and breast computed tomography investigations.

Perfusion phantom for the optimization of dynamic contrast-enhanced dedicated breast CT: iodine contrast curves in a simplified breast phantom

“…10 We will experiment with at least two printing materials (PLA and clear resin) to create the tumor phantom. 6,11,12 Additionally, the possibility of printing differently-shaped tumors and creating tumor representations with areas of varying perfusion will be explored.…”

“…5 The material (polylactic acid (PLA)) was chosen based on its expected x-ray attenuation and the resemblance to the x-ray attenuation of skin. 6 Olive oil was used as a filling material since it is known to be a suitable representation of fatty breast tissue. 7 The phantom is connected to a perfusion system to generate flow patterns (Figure 1).…”

Measuring effective attenuation coefficients of 3D printing materials for anthropomorphic breast phantoms

“…Therefore, phantoms must mimic the anatomical complexity and the x-ray attenuation coefficients (µ) of breast tissues. [1][2][3][4][5][6][7] The X-ray attenuation coefficients of breast tissue-equivalent materials have been measured using spectrometry techniques 3,4 and breast X-ray image systems. 2 In recent years, 3D printing technology has been employed to create compressed and uncompressed physical breast phantoms using a variety of additive manufacturing techniques and materials.…”

“…2 In recent years, 3D printing technology has been employed to create compressed and uncompressed physical breast phantoms using a variety of additive manufacturing techniques and materials. 1 The attenuation properties of 3D printing materials have been analyzed with monochromatic beams generated in a synchrotron 5,6 or higher energies than those used in breast X-ray imaging. 7 The objective of this work is to estimate the effective X-ray attenuation coefficient (µ ef f ) of 3D printing materials for polyenergetic X-ray beams emitted by clinical breast X-ray imaging systems.…”

Characterization of selected additive manufacturing materials for synchrotron monochromatic imaging and broad-beam radiotherapy at the Australian synchrotron-imaging and medical beamline

“…There are published studies on the investigation of experimental attenuation coefficient of AM materials using monochromatic synchrotron x-rays to fabricate a physical breast imaging phantom (Ivanov et al 2018, Mettivier et al 2022. However, these data are still limited to selected AM materials and focused on selected energies for breast imaging application.…”