1
|
Ahmed AMM, Buschmann M, Breyer L, Kuntner C, Homolka P. Tailoring the Mass Density of 3D Printing Materials for Accurate X-ray Imaging Simulation by Controlled Underfilling for Radiographic Phantoms. Polymers (Basel) 2024; 16:1116. [PMID: 38675035 PMCID: PMC11053449 DOI: 10.3390/polym16081116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 03/26/2024] [Accepted: 04/11/2024] [Indexed: 04/28/2024] Open
Abstract
Additive manufacturing and 3D printing allow for the design and rapid production of radiographic phantoms for X-ray imaging, including CT. These are used for numerous purposes, such as patient simulation, optimization of imaging procedures and dose levels, system evaluation and quality assurance. However, standard 3D printing polymers do not mimic X-ray attenuation properties of tissues like soft, adipose, lung or bone tissue, and standard materials like liquid water. The mass density of printing polymers-especially important in CT-is often inappropriate, i.e., mostly too high. Different methods can be applied to reduce mass density. This work examines reducing density by controlled underfilling either realized by using 3D printing materials expanded through foaming during heating in the printing process, or reducing polymer flow to introduce microscopic air-filled voids. The achievable density reduction depends on the base polymer used. When using foaming materials, density is controlled by the extrusion temperature, and ranges from 33 to 47% of the base polymer used, corresponding to a range of -650 to -394 HU in CT with 120 kV. Standard filaments (Nylon, modified PLA and modified ABS) allowed density reductions by 20 to 25%, covering HU values in CT from -260 to 77 (Nylon), -230 to -20 (ABS) and -81 to 143 (PLA). A standard chalk-filled PLA filament allowed reproduction of bone tissue in a wide range of bone mineral content resulting in CT numbers from 57 to 460 HU. Controlled underfilling allowed the production of radiographic phantom materials with continuously adjustable attenuation in a limited but appropriate range, allowing for the reproduction of X-ray attenuation properties of water, adipose, soft, lung, and bone tissue in an accurate, predictable and reproducible manner.
Collapse
Affiliation(s)
| | - Martin Buschmann
- Division of Medical Radiation Physics, Department of Radiation Oncology, Medical University of Vienna, and University Hospital Vienna, 1090 Vienna, Austria;
| | - Lara Breyer
- Department of Biomedical Imaging and Image-Guided Therapy, Medical Imaging Cluster (MIC), Medical University of Vienna, 1090 Vienna, Austria; (L.B.); (C.K.)
| | - Claudia Kuntner
- Department of Biomedical Imaging and Image-Guided Therapy, Medical Imaging Cluster (MIC), Medical University of Vienna, 1090 Vienna, Austria; (L.B.); (C.K.)
| | - Peter Homolka
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, 1090 Vienna, Austria
| |
Collapse
|
2
|
Shabbak A, Masoumkhani F, Fallah A, Amani-Beni R, Mohammadpour H, Shahbazi T, Bakhshi A. 3D Printing for Cardiovascular Surgery and Intervention: A Review Article. Curr Probl Cardiol 2024; 49:102086. [PMID: 37716537 DOI: 10.1016/j.cpcardiol.2023.102086] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 09/12/2023] [Indexed: 09/18/2023]
Abstract
3D printing technology can be applied to practically every aspect of modern life, fulfilling the needs of people from various backgrounds. The utilization of 3D printing in the context of adult heart disease can be succinctly categorized into 3 primary domains: preoperative strategizing or simulation, medical instruction, and clinical consultations. 3D-printed model utilization improves surgical planning and intraoperative decision-making and minimizes surgical risks, and it has demonstrated its efficacy as an innovative educational tool for aspiring surgeons with limited practical exposure. Despite all the applications of 3D printing, it has not yet been shown to improve long-term outcomes, including safety. There are no data on the outcomes of controlled trials available. To appropriately diagnose heart disease, 3D-printed models of the heart can provide a better understanding of the intracardiac anatomy and provide all the information needed for operative planning. Experientially, 3D printing provides a wide range of perceptions for understanding lower extremity arteries' spatial geometry and anatomical features of pathology. Practicing cardiac surgery processes using objects printed using 3D imaging data can become the norm rather than the exception, leading to improved accuracy and quality of treatment. This study aimed to review the various applications of 3D printing technology in cardiac surgery and intervention.
Collapse
Affiliation(s)
- Ali Shabbak
- Research Committee, School of Medicine, Guilan University of Medical Science, Rasht, Iran
| | - Fateme Masoumkhani
- Department of cardiology, Mousavi Hospital, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Amir Fallah
- Research Committee, School of Medicine, Guilan University of Medical Science, Rasht, Iran
| | - Reza Amani-Beni
- School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Hanieh Mohammadpour
- Research Committee, School of Medicine, Guilan University of Medical Science, Rasht, Iran
| | - Taha Shahbazi
- Neurosurgery Research Group (NRG), Student Research Committee, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Arash Bakhshi
- Remember of Research Committee, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran.
| |
Collapse
|
3
|
Mei K, Pasyar P, Geagan M, Liu LP, Shapira N, Gang GJ, Stayman JW, Noël PB. Design and fabrication of 3D-printed patient-specific soft tissue and bone phantoms for CT imaging. Sci Rep 2023; 13:17495. [PMID: 37840044 PMCID: PMC10577126 DOI: 10.1038/s41598-023-44602-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 10/10/2023] [Indexed: 10/17/2023] Open
Abstract
The objective of this study is to create patient-specific phantoms for computed tomography (CT) that possess accurate densities and exhibit visually realistic image textures. These qualities are crucial for 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 calcium-doped filament to increase the 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 visual texture and contrast. Micro-CT analysis revealed minimal variations between prints, with an overall deviation of ± 0.8% in filament line spacing and ± 0.022 mm in line width. Measured differences between patient and phantom were less than 12 HU for soft tissue and 15 HU for bone marrow, and 514 HU for cortical bone. The calcium-doped filament accurately represented bony tissue structures across different X-ray energies in spectral CT (RMSE ranging from ± 3 to ± 28 HU, compared to 400 mg/ml hydroxyapatite). 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.
Collapse
Affiliation(s)
- Kai Mei
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Pouyan Pasyar
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Michael Geagan
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Leening P Liu
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Nadav Shapira
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Grace J Gang
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - J Webster Stayman
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Peter B Noël
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Diagnostic and Interventional Radiology, School of Medicine and Klinikum Rechts der Isar, Technical University of Munich, 81675, Munich, Germany
| |
Collapse
|
4
|
Kunert P, Schlattl H, Trinkl S, Giussani A, Klein L, Janich M, Reichert D, Brix G. Reproduction of a conventional anthropomorphic female chest phantom by 3D-printing: Comparison of image contrasts and absorbed doses in CT. Med Phys 2023; 50:4734-4743. [PMID: 37415411 DOI: 10.1002/mp.16587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/10/2023] [Accepted: 06/11/2023] [Indexed: 07/08/2023] Open
Abstract
BACKGROUND The 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. PURPOSE To 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. METHODS In 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. RESULTS CT 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. CONCLUSION 3D-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.
Collapse
Affiliation(s)
- Patrizia Kunert
- Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Oberschleißheim, Germany
| | - Helmut Schlattl
- Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Oberschleißheim, Germany
| | - Sebastian Trinkl
- Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Oberschleißheim, Germany
| | - Augusto Giussani
- Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Oberschleißheim, Germany
| | - Lea Klein
- Department of Radiation Oncology, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Martin Janich
- Department of Radiation Oncology, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Detlef Reichert
- Department of Physics, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Gunnar Brix
- Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Oberschleißheim, Germany
| |
Collapse
|
5
|
Hatamikia S, Jaksa L, Kronreif G, Birkfellner W, Kettenbach J, Buschmann M, Lorenz A. Silicone phantoms fabricated with multi-material extrusion 3D printing technology mimicking imaging properties of soft tissues in CT. Z Med Phys 2023:S0939-3889(23)00076-4. [PMID: 37380561 DOI: 10.1016/j.zemedi.2023.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 05/20/2023] [Accepted: 05/21/2023] [Indexed: 06/30/2023]
Abstract
Recently, 3D printing has been widely used to fabricate medical imaging phantoms. So far, various rigid 3D printable materials have been investigated for their radiological properties and efficiency in imaging phantom fabrication. However, flexible, soft tissue materials are also needed for imaging phantoms for simulating several clinical scenarios where anatomical deformations is important. Recently, various additive manufacturing technologies have been used to produce anatomical models based on extrusion techniques that allow the fabrication of soft tissue materials. To date, there is no systematic study in the literature investigating the radiological properties of silicone rubber materials/fluids for imaging phantoms fabricated directly by extrusion using 3D printing techniques. The aim of this study was to investigate the radiological properties of 3D printed phantoms made of silicone in CT imaging. To achieve this goal, the radiodensity as described as Hounsfield Units (HUs) of several samples composed of three different silicone printing materials were evaluated by changing the infill density to adjust their radiological properties. A comparison of HU values with a Gammex Tissue Characterization Phantom was performed. In addition, a reproducibility analysis was performed by creating several replicas for specific infill densities. A scaled down anatomical model derived from an abdominal CT was also fabricated and the resulting HU values were evaluated. For the three different silicone materials, a spectrum ranging from -639 to +780 HU was obtained on CT at a scan setting of 120 kVp. In addition, using different infill densities, the printed materials were able to achieve a similar radiodensity range as obtained in different tissue-equivalent inserts in the Gammex phantom (238 HU to -673 HU). The reproducibility results showed good agreement between the HU values of the replicas compared to the original samples, confirming the reproducibility of the printed materials. A good agreement was observed between the HU target values in abdominal CT and the HU values of the 3D-printed anatomical phantom in all tissues.
Collapse
Affiliation(s)
- Sepideh Hatamikia
- Austrian Center for Medical Innovation and Technology (ACMIT), Wiener Neustadt, Austria; Research Center for Medical Image Analysis and Artificial Intelligence (MIAAI), Department of Medicine, Danube Private University, Krems, Austria.
| | - Laszlo Jaksa
- Austrian Center for Medical Innovation and Technology (ACMIT), Wiener Neustadt, Austria
| | - Gernot Kronreif
- Austrian Center for Medical Innovation and Technology (ACMIT), Wiener Neustadt, Austria
| | - Wolfgang Birkfellner
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Joachim Kettenbach
- Institute of Diagnostic, Interventional Radiology and Nuclear Medicine, Landesklinikum Wiener Neustadt, Wiener Neustadt, Austria
| | - Martin Buschmann
- Department of Radiation Oncology, Medical University of Vienna/AKH Wien, Vienna, Austria
| | - Andrea Lorenz
- Austrian Center for Medical Innovation and Technology (ACMIT), Wiener Neustadt, Austria
| |
Collapse
|
6
|
Mei K, Pasyar P, Geagan M, Liu LP, Shapira N, Gang GJ, Stayman JW, Noël PB. Design and fabrication of 3D-printed patient-specific soft tissue and bone phantoms for CT imaging. RESEARCH SQUARE 2023:rs.3.rs-2828218. [PMID: 37162901 PMCID: PMC10168445 DOI: 10.21203/rs.3.rs-2828218/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
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.
Collapse
|
7
|
Mei K, Pasyar P, Geagan M, Liu LP, Shapira N, Gang GJ, Stayman JW, Noël PB. Design and fabrication of 3D-printed patient-specific soft tissue and bone phantoms for CT imaging. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.04.17.23288689. [PMID: 37162973 PMCID: PMC10168421 DOI: 10.1101/2023.04.17.23288689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
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.
Collapse
Affiliation(s)
- Kai Mei
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Pouyan Pasyar
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Michael Geagan
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Leening P. Liu
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
| | - Nadav Shapira
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Grace J. Gang
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - J. Webster Stayman
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Peter B. Noël
- Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Department of Diagnostic and Interventional Radiology, School of Medicine & Klinikum rechts der Isar, Technical University of Munich, 81675 München, Germany
| |
Collapse
|
8
|
Jusufbegović M, Pandžić A, Busuladžić M, Čiva LM, Gazibegović-Busuladžić A, Šehić A, Vegar-Zubović S, Jašić R, Beganović A. Utilisation of 3D Printing in the Manufacturing of an Anthropomorphic Paediatric Head Phantom for the Optimisation of Scanning Parameters in CT. Diagnostics (Basel) 2023; 13:diagnostics13020328. [PMID: 36673137 PMCID: PMC9858362 DOI: 10.3390/diagnostics13020328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 11/27/2022] [Accepted: 11/29/2022] [Indexed: 01/18/2023] Open
Abstract
Computed tomography (CT) is a diagnostic imaging process that uses ionising radiation to obtain information about the interior anatomic structure of the human body. Considering that the medical use of ionising radiation implies exposing patients to radiation that may lead to unwanted stochastic effects and that those effects are less probable at lower doses, optimising imaging protocols is of great importance. In this paper, we used an assembled 3D-printed infant head phantom and matched its image quality parameters with those obtained for a commercially available adult head phantom using the imaging protocol dedicated for adult patients. In accordance with the results, an optimised scanning protocol was designed which resulted in dose reductions for paediatric patients while keeping image quality at an adequate level.
Collapse
Affiliation(s)
- Merim Jusufbegović
- Radiology Clinic, Sarajevo University Clinical Center, 71000 Sarajevo, Bosnia and Herzegovina
- Department of Radiological Technologies, Faculty of Health Studies, University of Sarajevo, 71000 Sarajevo, Bosnia and Herzegovina
| | - Adi Pandžić
- Department of Mechanical Production Engineering, Faculty of Mechanical Engineering Sarajevo, 71000 Sarajevo, Bosnia and Herzegovina
| | - Mustafa Busuladžić
- Faculty of Medicine, University of Sarajevo, 71000 Sarajevo, Bosnia and Herzegovina
| | - Lejla M. Čiva
- Sarajevo Medical School, University Sarajevo School of Science and Technology, 71210 Ilidža, Bosnia and Herzegovina
| | | | - Adnan Šehić
- Department of Radiological Technologies, Faculty of Health Studies, University of Sarajevo, 71000 Sarajevo, Bosnia and Herzegovina
| | - Sandra Vegar-Zubović
- Radiology Clinic, Sarajevo University Clinical Center, 71000 Sarajevo, Bosnia and Herzegovina
- Faculty of Medicine, University of Sarajevo, 71000 Sarajevo, Bosnia and Herzegovina
| | - Rahima Jašić
- Department of Radiation Protection and Medical Physics, Sarajevo University Clinical Center, 71000 Sarajevo, Bosnia and Herzegovina
| | - Adnan Beganović
- Faculty of Science, University of Sarajevo, 71000 Sarajevo, Bosnia and Herzegovina
- Department of Radiation Protection and Medical Physics, Sarajevo University Clinical Center, 71000 Sarajevo, Bosnia and Herzegovina
- Correspondence:
| |
Collapse
|
9
|
Hatamikia S, Gulyas I, Birkfellner W, Kronreif G, Unger A, Oberoi G, Lorenz A, Unger E, Kettenbach J, Figl M, Patsch J, Strassl A, Georg D, Renner A. Realistic 3D printed CT imaging tumor phantoms for validation of image processing algorithms. Phys Med 2023; 105:102512. [PMID: 36584415 DOI: 10.1016/j.ejmp.2022.102512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 11/06/2022] [Accepted: 12/15/2022] [Indexed: 12/30/2022] Open
Abstract
Medical imaging phantoms are widely used for validation and verification of imaging systems and algorithms in surgical guidance and radiation oncology procedures. Especially, for the performance evaluation of new algorithms in the field of medical imaging, manufactured phantoms need to replicate specific properties of the human body, e.g., tissue morphology and radiological properties. Additive manufacturing (AM) technology provides an inexpensive opportunity for accurate anatomical replication with customization capabilities. In this study, we proposed a simple and cheap protocol using Fused Deposition Modeling (FDM) technology to manufacture realistic tumor phantoms based on the filament 3D printing technology. Tumor phantoms with both homogenous and heterogeneous radiodensity were fabricated. The radiodensity similarity between the printed tumor models and real tumor data from CT images of lung cancer patients was evaluated. Additionally, it was investigated whether a heterogeneity in the 3D printed tumor phantoms as observed in the tumor patient data had an influence on the validation of image registration algorithms. A radiodensity range between -217 to 226 HUs was achieved for 3D printed phantoms using different filament materials; this range of radiation attenuation is also observed in the human lung tumor tissue. The resulted HU range could serve as a lookup-table for researchers and phantom manufactures to create realistic CT tumor phantoms with the desired range of radiodensities. The 3D printed tumor phantoms also precisely replicated real lung tumor patient data regarding morphology and could also include life-like heterogeneity of the radiodensity inside the tumor models. An influence of the heterogeneity on accuracy and robustness of the image registration algorithms was not found.
Collapse
Affiliation(s)
- Sepideh Hatamikia
- Austrian Center for Medical Innovation and Technology, Wiener Neustadt, Austria; Research Center for Medical Image Analysis and Artificial Intelligence (MIAAI), Department of Medicine, Danube Private University, Krems, Austria; Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
| | - Ingo Gulyas
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Birkfellner
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Gernot Kronreif
- Austrian Center for Medical Innovation and Technology, Wiener Neustadt, Austria
| | - Alexander Unger
- Austrian Center for Medical Innovation and Technology, Wiener Neustadt, Austria
| | - Gunpreet Oberoi
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Andrea Lorenz
- Austrian Center for Medical Innovation and Technology, Wiener Neustadt, Austria
| | - Ewald Unger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Joachim Kettenbach
- Institute of Diagnostic, Interventional Radiology and Nuclear Medicine, Landesklinikum Wiener Neustadt, Wiener Neustadt, Austria
| | - Michael Figl
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Janina Patsch
- Department of Radiology and Nuclear Medicine, Medical University Vienna, Austria
| | - Andreas Strassl
- Department of Radiology and Nuclear Medicine, Medical University Vienna, Austria
| | - Dietmar Georg
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
| | - Andreas Renner
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
| |
Collapse
|
10
|
X-ray attenuation of bone, soft and adipose tissue in CT from 70 to 140 kV and comparison with 3D printable additive manufacturing materials. Sci Rep 2022; 12:14580. [PMID: 36028638 PMCID: PMC9418162 DOI: 10.1038/s41598-022-18741-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Accepted: 08/18/2022] [Indexed: 11/17/2022] Open
Abstract
Additive manufacturing and 3D printing are widely used in medical imaging to produce phantoms for image quality optimization, imaging protocol definition, comparison of image quality between different imaging systems, dosimetry, and quality control. Anthropomorphic phantoms mimic tissues and contrasts in real patients with regard to X-ray attenuation, as well as dependence on X-ray spectra. If used with different X-ray energies, or to optimize the spectrum for a certain procedure, the energy dependence of the attenuation must replicate the corresponding energy dependence of the tissues mimicked, or at least be similar. In the latter case the materials’ Hounsfield values need to be known exactly to allow to correct contrast and contrast to noise ratios accordingly for different beam energies. Fresh bovine and porcine tissues including soft and adipose tissues, and hard tissues from soft spongious bone to cortical bone were scanned at different energies, and reference values of attenuation in Hounsfield units (HU) determined. Mathematical model equations describing CT number dependence on kV for bones of arbitrary density, and for adipose tissues are derived. These data can be used to select appropriate phantom constituents, compare CT values with arbitrary phantom materials, and calculate correction factors for phantoms consisting of materials with an energy dependence different to the tissues. Using data on a wide number of additive manufacturing and 3D printing materials, CT numbers and their energy dependence were compared to those of the tissues. Two commercially available printing filaments containing calcium carbonate powder imitate bone tissues with high accuracy at all kV values. Average adipose tissue can be duplicated by several off-the-shelf printing polymers. Since suitable printing materials typically exhibit a too high density for the desired attenuation of especially soft tissues, controlled density reduction by underfilling might improve tissue equivalence.
Collapse
|
11
|
Additively manufactured test phantoms for mimicking soft tissue radiation attenuation in CBCT using Polyjet technology. Z Med Phys 2022:S0939-3889(22)00063-0. [PMID: 35792011 DOI: 10.1016/j.zemedi.2022.05.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 04/27/2022] [Accepted: 05/27/2022] [Indexed: 01/14/2023]
Abstract
OBJECTIVES To develop and validate a simple approach for building cost-effective imaging phantoms for Cone Beam Computed Tomography (CBCT) using a modified Polyjet additive manufacturing technology where a single material can mimic a range of human soft-tissue radiation attenuation. MATERIALS AND METHODS Single material test phantoms using a cubic lattice were designed in 3-Matic 15.0 software . Keeping the individual cubic lattice volume constant, eight different percentage ratio (R) of air: material from 0% to 70% with a 10% increment were assigned to each sample. The phantoms were printed in three materials, namely Vero PureWhite, VeroClear and TangoPlus using Polyjet technology. The CT value analysis, non-contact profile measurement and microCT-based volumetric analysis was performed for all the samples. RESULTS The printed test phantoms produced a grey value spectrum equivalent to the radiation attenuation of human soft tissues in the range of -757 to +286 HU on CT. The results from dimensional comparison analysis of the printed phantoms with the digital test phantoms using non-contact profile measurement showed a mean accuracy of 99.07 % and that of micro-CT volumetric analysis showed mean volumetric accuracy of 84.80-94.91%. The material and printing costs of developing 24 test phantoms was 83.00 Euro. CONCLUSIONS The study shows that additive manufacturing-guided macrostructure manipulation modifies successfully the radiographic visibility of a material in CBCT imaging with 1 mm3 resolution, helping customization of imaging phantoms.
Collapse
|