A filament 3D printing approach for CT-compatible bone tissues replication

Okkalidis, Nikiforos; Bliznakova, Kristina; Kolev, Nikola

doi:10.1016/j.ejmp.2022.09.009

“…In contrast to prior studies of image-based 3D printed bone phantoms using slices of the human head/skull [13], chest/thoracic cage [15], pelvis [14] and femoral shaft [6], this study printed the human cervical vertebrae with surrounding soft tissue. Human vertebrae particularly present a challenging task for 3D printing, as they contain intricate details and are comparatively smaller in size.…”

Section: Discussionmentioning

confidence: 99%

Design and fabrication of 3D-printed patient-specific soft tissue and bone phantoms for CT imaging

Mei

¹

,

Pasyar

²

,

Geagan

³

et al. 2023

Preprint

0

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The objective of this study is to create patient-specific phantoms for computed tomography (CT) that have realistic image texture and densities, which are critical in evaluating CT performance in clinical settings. The study builds upon a previously presented 3D printing method (PixelPrint) by incorporating soft tissue and bone structures. We converted patient DICOM images directly into 3D printer instructions using PixelPrint and utilized stone-based filament to increase Hounsfield unit (HU) range. Density was modeled by controlling printing speed according to volumetric filament ratio to emulate attenuation profiles. We designed micro-CT phantoms to demonstrate the reproducibility and to determine mapping between filament ratios and HU values on clinical CT systems. Patient phantoms based on clinical cervical spine and knee examinations were manufactured and scanned with a clinical spectral CT scanner. The CT images of the patient-based phantom closely resembled original CT images in texture and contrast. Measured differences between patient and phantom were less than 15 HU for soft tissue and bone marrow. The stone-based filament accurately represented bony tissue structures across different X-ray energies, as measured by spectral CT. In conclusion, this study demonstrated the possibility of extending 3D-printed patient-based phantoms to soft tissue and bone structures while maintaining accurate organ geometry, image texture, and attenuation profiles.

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“…In contrast to prior studies of image-based 3D printed bone phantoms using slices of the human head/skull [13], chest/thoracic cage [15], pelvis [14] and femoral shaft [6], this study printed the human cervical vertebrae with surrounding soft tissue. Human vertebrae particularly present a challenging task for 3D printing, as they contain intricate details and are comparatively smaller in size.…”

Section: Discussionmentioning

confidence: 99%

Design and fabrication of 3D-printed patient-specific soft tissue and bone phantoms for CT imaging

Mei

¹

,

Pasyar

²

,

Geagan

³

et al. 2023

Preprint

0

View full text Add to dashboard Cite

The objective of this study is to create patient-specific phantoms for computed tomography (CT) that have realistic image texture and densities, which are critical in evaluating CT performance in clinical settings. The study builds upon a previously presented 3D printing method (PixelPrint) by incorporating soft tissue and bone structures. We converted patient DICOM images directly into 3D printer instructions using PixelPrint and utilized stone-based filament to increase Hounsfield unit (HU) range. Density was modeled by controlling printing speed according to volumetric filament ratio to emulate attenuation profiles. We designed micro-CT phantoms to demonstrate the reproducibility and to determine mapping between filament ratios and HU values on clinical CT systems. Patient phantoms based on clinical cervical spine and knee examinations were manufactured and scanned with a clinical spectral CT scanner. The CT images of the patient-based phantom closely resembled original CT images in texture and contrast. Measured differences between patient and phantom were less than 15 HU for soft tissue and bone marrow. The stone-based filament accurately represented bony tissue structures across different X-ray energies, as measured by spectral CT. In conclusion, this study demonstrated the possibility of extending 3D-printed patient-based phantoms to soft tissue and bone structures while maintaining accurate organ geometry, image texture, and attenuation profiles.

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“…For example, by mixing two different filament materials with well-defined fractions during the printing step, realistic glandular structures or bone compositions can be produced. [26][27][28] In addition, more realistic lungs can be printed by selective adjustment of infill densities for individual lung regions. 29,30 Especially when it comes to patient-specific phantoms, these or similar concepts should be considered to obtain more realistic image contrasts.…”

Section: Discussionmentioning

confidence: 99%

“…In this context, it has to be referred to various concepts to print more realistic phantoms with the MEX technology published most recently. For example, by mixing two different filament materials with well‐defined fractions during the printing step, realistic glandular structures or bone compositions can be produced 26–28 . In addition, more realistic lungs can be printed by selective adjustment of infill densities for individual lung regions 29,30 .…”

Section: Discussionmentioning

confidence: 99%

Reproduction of a conventional anthropomorphic female chest phantom by 3D‐printing: Comparison of image contrasts and absorbed doses in CT

Kunert

¹

,

Schlattl

²

,

Trinkl

³

et al. 2023

Medical Physics

3

0

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BackgroundThe production of individualized anthropomorphic phantoms via three‐dimensional (3D) printing methods offers promising possibilities to assess and optimize radiation exposures for specifically relevant patient groups (i.e., overweighed or pregnant persons) that are not adequately represented by standardized anthropomorphic phantoms. However, the equivalence of printed phantoms must be demonstrated exemplarily with respect to the resulting image contrasts and dose distributions.PurposeTo reproduce a conventionally produced anthropomorphic phantom of a female chest and breasts and to evaluate their equivalence with respect to image contrasts and absorbed doses at the example of a computed tomography (CT) examination of the chest.MethodsIn a first step, the effect of different print settings on the CT values of printed samples was systematically investigated. Subsequently, a transversal slice and breast add‐ons of a conventionally produced female body phantom were reproduced using a multi‐material extrusion‐based printer, considering six different types of tissues (muscle, lung, adipose, and glandular breast tissue, as well as bone and cartilage). CT images of the printed and conventionally produced phantom parts were evaluated with respect to their geometric correspondence, image contrasts, and absorbed doses measured using thermoluminescent dosimeters.ResultsCT values of printed objects are highly sensitive to the selected print settings. The soft tissues of the conventionally produced phantom could be reproduced with a good agreement. Minor differences in CT values were observed for bone and lung tissue, whereas absorbed doses to the relevant tissues were identical within the measurement uncertainties.Conclusion3D‐printed phantoms are with exception of minor contrast differences equivalent to their conventionally manufactured counterparts. When comparing the two production techniques, it is important to note that conventionally manufactured phantoms should not be considered as absolute benchmarks, as they also only approximate the human body in terms of its absorption, and attenuation of x‐rays as well as its geometry.

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A filament 3D printing approach for CT-compatible bone tissues replication

Cited by 13 publications

References 32 publications

Design and fabrication of 3D-printed patient-specific soft tissue and bone phantoms for CT imaging

Design and fabrication of 3D-printed patient-specific soft tissue and bone phantoms for CT imaging

Design and fabrication of 3D-printed patient-specific soft tissue and bone phantoms for CT imaging

Reproduction of a conventional anthropomorphic female chest phantom by 3D‐printing: Comparison of image contrasts and absorbed doses in CT

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