Temporal bone (a, b) and liver (c, d) images reconstructed with soft (a, c) and sharp kernels (b, d) 

Temporal bone (a, b) and liver (c, d) images reconstructed with soft (a, c) and sharp kernels (b, d) 

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Background The purpose of this study is to provide a framework for the development of a quality assurance (QA) program for use in medical 3D printing applications. An interdisciplinary QA team was built with expertise from all aspects of 3D printing. A systematic QA approach was established to assess the accuracy and precision of each step during t...

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... Many commercially available phantoms are currently in use. However, many researchers have engaged in the production of self-made, personalized, and relatively low-cost anthropomorphic phantoms using different modes of computer-aided design (CAD) and additive manufacturing of three-dimensional (3D) objects, commonly referred to as 3D printing [6][7][8][9][10][11][12]. ...
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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.
... On the other hand, this technique's restrictions are linked with particular built-part quality issues, such as notable porosity (Charlon et al., 2021) (affecting mainly the mechanical properties of the parts (Arifvianto et al., 2021;Guessasma et al., 2019;Liao et al., 2019;von Windheim et al., 2021), limited dimensional accuracy (Aslani et al., 2020a), and elevated surface roughness (Delfs et al., 2016). The evaluation of the 3DP parts' quality and quality assurance is primarily based on how well they perform in terms of the aforementioned characteristics (Leng et al., 2017;Radhwan et al., 2020;Wu and Chen, 2018), not only for the MEX process but also for a number of other AM techniques such as material jetting (Li et al., 2017;N. Vidakis et al., 2020) and vat photopolymerization (Arnold et al., 2019;Vaidya and Solgaard, 2018). ...
... CT scanning (Dorweiler et al., 2021;Farzadi et al., 2014;Leng et al., 2017;Ogden et al., 2015), CMM (Islam et al., 2013;Mahmood et al., 2018), manual measurements (Melenka et al., 2015), and optical scanning (Boca et al., 2020;Santana et al., 2017) have been used in the literature to measure the dimensional accuracy of the 3DP parts. For the evaluation of the accuracy of industrial items, CT scanning and CMM are well-proven metrology techniques (Müller et al., 2013 (Nath et al., 2020). ...
... The geometrical deviation (dimensional accuracy) is assessed manually using a caliper in the literature (Radhwan et al., 2020), however, in the work presented here, a more sophisticated method employing CT scanning was utilized. Studies on the dimensional accuracy of 3DP items using more sophisticated measurements (Dorweiler et al., 2021;Farzadi et al., 2014;Leng et al., 2017;Ogden et al., 2015) do not use modeling tools for process optimization. Studies that used statistical analysis similar to the current study's (L50, five control parameters, and five levels) only considered surface roughness (Mushtaq et al., 2022) or dimensional accuracy (Elkaseer et al., 2020a). ...
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In the material extrusion (MEX) Additive Manufacturing (AM) technology, the layer-by-layer nature of the fabricated parts, induces specific features which affect their quality and may restrict their operating performance. Critical quality indicators with distinct technological and industrial impact are surface roughness, dimensional accuracy, and porosity, among others. Their achieving scores can be optimized by adjusting the 3D printing process parameters. The effect of six (6) 3D printing control parameters, i.e., raster deposition angle, infill density, nozzle temperature, bed temperature, printing speed, and layer thickness, on the aforementioned quality indicators is investigated herein. Optical Microscopy, Optical Profilometry, and Micro Χ-Ray Computed Tomography were employed to investigate and document these quality characteristics. Experimental data were processed with Robust Design Theory. An L25 Taguchi orthogonal array (twenty-five runs) was compiled, for the six control parameters with five levels for each one of them. The predictive quadratic regression models were then validated with two additional confirmation runs, with five replicas each. For the first time, the surface quality features, as well as the geometrical and structural characteristics were investigated in such depth (>500 GB of raw experimental data were produced and processed). A deep insight into the quality of the MEX 3D printed parts is provided allowing the control parameters’ ranking and optimization. Prediction equations for the quality features as functions of the control parameters are introduced herein, with merit in the market-driven practice.
... [10,23] The technology has yet to become part of standard practice, with universal quality assurance under development. [24,25] This study aims to address key deficits of the current process. We propose a novel, simple, rapid, and open-source method to create virtual 3D models using the Drishti software (National Computational Infrastructure of Australia, Canberra, Australia) to allow orthopaedic surgeons to generate their own high-quality 3D printable models of complex fractures. ...
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Objectives: Although 3-dimensional (3D) printing is becoming more widely adopted for clinical applications, it is yet to be accepted as part of standard practice. One of the key applications of this technology is orthopaedic surgical planning for urgent trauma cases. Anatomically accurate replicas of patients' fracture models can be produced to guide intervention. These high-quality models facilitate the design and printing of patient-specific implants and surgical devices. Therefore, a fast and accurate workflow will help orthopaedic surgeons to generate high-quality 3D printable models of complex fractures. Currently, there is a lack of access to an uncomplicated and inexpensive workflow. Methods: Using patient DICOM data sets (n = 13), we devised a novel, simple, open-source, and rapid modeling process using Drishti software and compared its efficacy and data storage with the 3D Slicer image computing platform. We imported the computed tomography image directory acquired from patients into the software to isolate the model of bone surface from surrounding soft tissue using the minimum functions. One pelvic fracture case was further integrated into the customized implant design practice to demonstrate the compatibility of the 3D models generated from Drishti. Results: The data sizes of the generated 3D models and the processing files that represent the original DICOM of Drishti are on average 27% and 12% smaller than that of 3D Slicer, respectively (both P < 0.05). The time frame needed to reach the stage of viewing the 3D bone model and the exporting of the data of Drishti is 39% and 38% faster than that of 3D Slicer, respectively (both P < 0.05). We also constructed a virtual model using third-party software to trial the implant design. Conclusions: Drishti is more suitable for urgent trauma cases that require fast and efficient 3D bone reconstruction with less hardware requirement. 3D Slicer performs better at quantitative preoperative planning and multilayer segmentation. Both software platforms are compatible with third-party programs used to produce customized implants that could be useful for surgical training. Level of Evidence: Level V.
... Further identifiers denoting directionality (left or right) or directional terms (dorsal/superficial/medial etc.) may be etched on models if appropriate. STL files and photographs of anatomic models used should be included in the patient's medical record; this way, files can be used to reprint models without re-segmentation if necessary, and models can be examined later for any errors or additional medical evaluations [72]. ...
... A quality assurance (QA) program could be productive in maintaining high-quality prints throughout the lifespan of a 3D printer. Leng et al. discuss the benefit of developing a QA approach at each of the key steps of 3D printingimage acquisition, segmentation, and printing [72]. For imaging, steps can be taken to optimize the CT or MRI image before segmentation and processing occur; this can include using a lower tube potential in CT to enhance iodine contrast for vascular models [72,73]. ...
... Leng et al. discuss the benefit of developing a QA approach at each of the key steps of 3D printingimage acquisition, segmentation, and printing [72]. For imaging, steps can be taken to optimize the CT or MRI image before segmentation and processing occur; this can include using a lower tube potential in CT to enhance iodine contrast for vascular models [72,73]. Even after printing, the final model can be assessed via physical measurements using tools such as a caliper or protractor [72]. ...
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Three-dimensional (3D) printing has applications in many fields and has gained substantial traction in medicine as a modality to transform two-dimensional scans into three-dimensional renderings. Patient-specific 3D printed models have direct patient care uses in surgical and procedural specialties, allowing for increased precision and accuracy in developing treatment plans and guiding surgeries. Medical applications include surgical planning, surgical guides, patient and trainee education, and implant fabrication. 3D printing workflow for a laboratory or clinical service that produces anatomic models and guides includes optimizing imaging acquisition and post-processing, segmenting the imaging, and printing the model. Quality assurance considerations include supervising medical imaging expert radiologists' guidance and self-implementing in-house quality control programs. The purpose of this review is to provide a workflow and guide for starting or optimizing laboratories and clinical services that 3D-print anatomic models or guides for clinical use.
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... Furthermore, they rely on scalar values or one and two dimensional metrics [3,4] to describe increasingly complex 3D scaffolds. More comprehensive 3D QA metrics have been accomplished but require manual input in difficult cases such as porous objects [5]. In the laboratory setting, fabrication quality is typically characterized by qualitative methods that include scanning electron microscopy (SEM), and stereoscopic or brightfield imaging, and quantitative techniques such as computed tomography (CT) scans. ...
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... In contrast, the disseminated nature of the 3DP process precludes such a conventional regulatory framework. Thus, only the tools (software, hardware) and the process itself can be certified, whereas the responsibility to adhere to the manufacturing procedure falls on the healthcare provider, and specifically on each actor involved in the 3DP process [184,185]. Although it is hard to find published documentation of a 3D-printed model having misled clinical decisions, it is not difficult to imagine such a scenario. ...
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... During and after AM process, simultaneous monitoring of strain and temperature for 3D printed products is critical for understanding the curing deformation which significantly influence the quality and integrity of printed products [24,15]. Unevenly cooling after printing may lead to significant stress contraction, causing typical internal cracks or warping problems. ...
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Additive Manufacturing (AM) techniques are under continuous investigation with interesting results published at both experimental and research levels. However, few investigations have been found focusing on the measurement study of internal mechanical performance which significantly influences the quality of printed products. In this study, several clay soil specimens with infill densities of 40%, 60%, 80%, and 100% were fabricated using AM method. Fiber Bragg grating (FBG) sensors were successfully mounted at the center of soil specimens (forming smart 3D printed clay soils) to monitor the horizontal strain distributions at different testing conditions. During AM process, lateral strain distributed at the horizontal center of all soil specimens presents linear rise as the increase of infill density from 40 to 100%. The strain values measured by FBG sensors are within a range between 22 and 210 με. In soil drying process, all strain values from FBG sensors present nonlinear decrease against time with a relatively stable residual level obtained at certain time after AM. The increase of infill density from 40 to 100% leads to a corresponding shrinkage strain up to a range from − 800 to 1400 με. In uniaxial loading tests, measured strains from FBG sensors present initial quick rise approaching two peak wavelength values. All measured strains at the center of soil specimens increase linearly as the increase of infill density values. Peak lateral strain almost doubled as the infill density increases from 40 to 100%. In this study, FBG sensor offers an effective monitoring method to investigate mechanical behavior of printed soils.
... También se cuenta con diversidad de colores y propiedades mecánicas con potencial para la esterilización. de allí, la importancia de los programas de aseguramiento de calidad (QA) como parte del desarrollo y mantenimiento para garantizar la eficacia de la técnica [5]. ...
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En el desarrollo de nuevas tecnologías, se halló, por medio de diferentes artículos, que el uso de impresiones tridimensionales en el área de la salud y la educación se incrementó, evidenciándolo en el complemento para el tratamiento de enfermedades específicas al emplear modelos anatómicos. Entre la variabilidad de utilidades de la impresión tridimensional, se encontró la formación de residentes en proceso de aprendizaje, donde es utilizada como herramienta aplicativa de investigación y simulación. Se comprobó que los procesos pueden llevar a un margen de error entre modelos, dependiendo del software y material utilizados para su creación. Sin embargo, este hallazgo contribuyó a la búsqueda de calidad, para obtener mejores beneficios. La nueva tecnología en impresión tridimensional revolucionó el arte de la enseñanza anatómica y procedimental, generando un alto impacto en el desarrollo de nuevas tecnologías. Por tanto, se originó mayor expectativa en el uso de esta herramienta en otras áreas.
... A systematic quality assurance approach should be established to ensure the accuracy of each step during the AR process including image acquisition, segmentation and processing, and co-registration of AR content. It is expected that Quality Assurance (QA) programs for AR models will be similar to those that are being established for 3D printed anatomic models and guides [33,34]. Improvements in AR, VR, and 3D printing technologies are continuously being made and an increasing number of groups are using these technologies in their medical practices. ...
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Augmented reality (AR) and virtual reality (VR) are burgeoning technologies that have the potential to greatly enhance patient care. Visualizing patient-specific three-dimensional (3D) imaging data in these enhanced virtual environments may improve surgeons’ understanding of anatomy and surgical pathology, thereby allowing for improved surgical planning, superior intra-operative guidance, and ultimately improved patient care. It is important that radiologists are familiar with these technologies, especially since the number of institutions utilizing VR and AR is increasing. This article gives an overview of AR and VR and describes the workflow required to create anatomical 3D models for use in AR using the Microsoft HoloLens device. Case examples in urologic oncology (prostate cancer and renal cancer) are provided which depict how AR has been used to guide surgery at our institution.