Low-cost Phantom Research Articles

Computed tomography imaging analysis of a fused filament fabrication (FFF) 3D printed neck-thyroid phantom for multidisciplinary purposes

The application of the 3D printing technique for the development of low-cost phantoms is being investigated recently and requires a complex study of the interaction of printed materials with different types and qualities of radiation, as well as the characterization of printing filaments to correctly simulate human tissue attenuation. This study aims to present the Computed Tomography (CT) Imaging analysis of a fused filament fabrication (FFF) 3D printed anthropomorphic neck-thyroid phantom. The commercial phantom ATOM MAX 711 from CIRS was used as anatomy of reference for the 3D modeling base of the neck-thyroid phantom. Commercially available PLA and ABS XCT-A validated at IPEN were used in the 3D printing process in order to simulate soft and bone tissues respectively. The printing process was done using the RAISE3D PRO 2 FFF printer from IPEN. The imaging study of the phantom was performed through the analysis of images from a CT acquisition, comparing the Hounsfield Units (HU) numbers of the tissues between both CIRS and 3D printed phantoms. The developed phantom is a feasible alternative and presents some desirable characteristics for applications in radiation protection, measurements of radioisotopes incorporated in the thyroid (both contamination counters and nuclear medicine detectors) and training of techniques of acquisition of images with X rays.

A low-cost phantom design for evaluating spine SABR calculations in the presence of prosthetic vertebral stabilization.

Dose-perturbation characteristics are important to consider during the calculation of radiation therapy protocols for patients who are going to receive high doses that would reach the tolerance limits of the spinal cord [1]. Several studies have investigated dose perturbations introduced by metal implants in close proximity to spine SABR treatments [2-7]. However, there is a lack of work assessing this effect using the RayStation TPS [8]. We present an initial design for a low-cost phantom to evaluate spine stereotactic ablative radiotherapy (SABR) in the presence of prosthetic vertebral stabilization. The phantom is modular, allowing the prosthetic at the centre of the phantom to be removed by exchanging the central block. It also includes space to insert ion chamber and film. The agreement of the RayStation TPS (v8.0B) collapsed cone convolution (CCC) calculation and measurement was determined for phantom versions with and without prosthetic. There was little to no change in the agreement between the measured and calculated dose when introducing metallic hardware. This suggests that our Raystation-based SABR planning approach for patients with spinal hardware meets clinical expectations. Departments without access to anthropomorphic phantoms may find this design useful but should test their phantom design in typical clinical settings to ensure it is robust to real world situations.

Construction of Low-Cost Simulators for Training in Minimally Invasive Breast Procedures.

The aim of this work was to describe a technique for building low-cost simulators for training in minimally invasive breast procedures guided by ultrasound (US) and stereotactic mammography (MMG), focusing mainly on training medical professionals studying related areas. Low-cost phantoms were developed using organic structures that mimic breast tissue, such as chicken breast and eggplant, and materials that simulate breast lesions. A step-by-step description of the preparation and use of these simulators was made, enabling the reproducibility of the technique by the physicians in training themselves. The low-cost phantoms showed a high degree of echogenic and radiological similarity with human breast tissue, allowing adequate training in minimally invasive procedures. It was possible to build low-cost phantoms that allow training in US- and stereotactic MMG-guided minimally invasive breast procedures.

A Review of Low-Cost Ultrasound Compatible Phantoms.

Ultrasound-compatible phantoms are used to develop novel US-based systems and train simulated medical interventions. The price difference between lab-made and commercially available ultrasound-compatible phantoms lead to the publication of many papers categorized as low-cost in the literature. The aim of this review was to improve the phantom selection process by summarizing the pertinent literature. We compiled papers on US-compatible spine, prostate, vascular, breast, kidney, and li ver phantoms. We reviewed papers for cost and accessibility, providing an overview of the materials, construction time, shelf life, needle insertion limits, and manufacturing and evaluation methods. This information was summarized by anatomy. The clinical application associated with each phantom was also reported for those interested in a particular intervention. Techniques and common practices for building low-cost phantoms were provided. Overall, this article aims to summarize a breadth of ultrasound-compatible phantom research to enable informed phantom methods selection.

A simplified low-cost phantom for image quality assessment of dental cone beam computed tomography unit.

A standardised testing protocol for evaluation of a wide range of dental cone beam computed tomography (CBCT) performance and image quality (IQ) parameters is still limited and commercially available testing tool is unaffordable by some centres. This study aims to assess the performance of a low-cost fabricated phantom for image quality assessment (IQA) of digital CBCT unit. A customised polymethyl methacrylate (PMMA) cylindrical phantom was developed for performance evaluation of Planmeca ProMax 3D Mid digital dental CBCT unit. The fabricated phantom consists of four different layers for testing specific IQ parameters such as CT number accuracy and uniformity, noise and CT number linearity. The phantom was scanned using common scanning protocols in clinical routine (90.0 kV, 8.0 mA and 13.6 s). In region-of-interest (ROI) analysis, the mean CT numbers (in Hounsfield unit, HU) and noise for water and air were determined and compared with the reference values (0 HU for water and -1000 HU for air). For linearity test, the correlation between the measured HU of different inserts with their density was studied. The average CT number were -994.1 HU and -2.4 HU, for air and water, respectively and the differences were within the recommended acceptable limit. The linearity test showed a strong positive correlation (R2 = 0.9693) between the measured HU and their densities. The fabricated IQ phantom serves as a simple and affordable testing tool for digital dental CBCT imaging.

Comparison of low-cost phantoms for ultrasound-guided fine-needle aspiration biopsy training.

Phantoms and simulators are widely accepted methods to gain valuable experience and confidence for inexperienced trainees prior to seeing their patient and for refining their skills. A phantom model that is durable, simple, and inexpensive to produce and use would be ideal to train practitioners in ultrasound-guided fine-needle aspiration biopsy (USFNA) technique. In this study, we systematically compared several low-cost phantom models including gelatin, extra firm tofu, canned cooked pork, ballistics gel, and chicken breast for their haptic properties, echogenicity, teaching utility, and overall performance based on a Likert scale (1-5; 5 = best). Nine cytopathologists and cytopathology fellows who perform FNA regularly evaluated these models and completed the survey. The gelatin phantom, with a gelatin to water ratio of 1:8 by weight, was found to be the best for USFNA practice and overall performance, followed by the 1:10 gelatin phantom. Tofu and chicken breast phantoms were also good low-cost alternatives that needed only a few minutes of total preparation time. Low-cost, homemade phantoms can serve as excellent alternatives to commercial phantoms for practicing and teaching USFNA.

Low-cost chest paediatric phantom for dose optimisation: construction and validation

Introduction and objectivesIn order to perform chest dose optimisation studies, the imaging phantom should be adequate for image quality evaluation. Since high-end phantoms are cost prohibitive, there is a need for a low-cost construction method with fairly available tissue substitutes. Materials and methodsTheoretical calculations of radiological characteristics were performed for each of lung, cortical bone and soft tissues in order to choose appropriate substitute, then, cork, P.V.C. (Polyvinyl chloride) and water were chosen, respectively. Validation included, firstly, measuring CT Hounsfield Units (HU) of a real patient’s tissues then compared against their corresponding anatomies in the constructed phantom. Secondly, Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) values were acquired in this study to evaluate the quality of images generated from the constructed phantom, then, compare their trends with a valid phantom under different exposure parameters (kVp and mAs). ResultsFrom theoretical calculations, the percentage differences showed high accuracy of tissue substitutes when simulating real patient tissues; P.V.C. was ≥5.78%, cork was ≥4.46% and water ≥5%. The percentage difference (CT HU) between lung and cortical bone and their equivalent tissue substitutes were 10.44% and 0.53%–3.17%, respectively. Strong positive correlations were found for SNR when changing both kVp (0.79) and mAs (0.65). While the correlation strength of CNR values were found to be moderate when changing both kVp (0.58) and mAs (0.53). ConclusionsOur low-cost phantom approved through CT HU that their materials replicate the radiological characteristics of real one-year-old child while SNR and SNR correlations confirmed its applicability in imaging and optimisation studies.

Construcción y validación de un fantoma torácico pediátrico asequible para optimizar la dosis

Introduction and ObjectivesIn order to perform chest dose optimisation studies, the imaging phantom should be adequate for image quality evaluation. Since high-end phantoms are cost prohibitive, there is a need for a low-cost construction method with fairly available tissue substitutes. Materials and MethodsTheoretical calculations of radiological characteristics were performed for each of lung, cortical bone and soft tissues in order to choose appropriate substitute, then, cork, P.V.C. (Polyvinyl Chloride) and water were chosen, respectively. Validation included, firstly, measuring CT Hounsfield Units (HU) of a real patient's tissues then compared against their corresponding anatomies in the constructed phantom. Secondly, Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) values were acquired in this study to evaluate the quality of images generated from the constructed phantom, then, compare their trends with a valid phantom under different exposure parameters (kVp and mAs). ResultsFrom theoretical calculations, the percentage differences showed high accuracy of tissue substitutes when simulating real patient tissues; P.V.C. was ≥ 5.78%, cork was ≥ 4.46% and water ≥ 5%. The percentage difference (CT HU) between lung and cortical bone and their equivalent tissue substitutes were 10.44% and 0.53%-3.17%, respectively. Strong positive correlations were found for SNR when changing both kVp (0.79) and mAs (0.65). While the correlation strength of CNR values were found to be moderate when changing both kVp (0.58) and mAs (0.53). ConclusionsOur low-cost phantom approved through CT HU that their materials replicate the radiological characteristics of real one-year-old child while SNR and SNR correlations confirmed its applicability in imaging and optimisation studies.

Comparison of Low-Cost Phantoms for Ultrasound Guided Fine Needle Aspiration Biopsy Teaching

Comparison of Low-Cost Phantoms for Ultrasound Guided Fine Needle Aspiration Biopsy Teaching

Electromagnetic Characterization of Breast Tissue Phantoms in D-Band Regime

The potential of higher band millimeter waves to characterize different types of breast tissues based on the dielectric contrast between normal and malignant tissues has been reported. Low–cost phantom samples of normal and malignant tissues have been prepared using naturally occurring components, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">i.e.</i> , agar, water, olive oil, and pectin. A waveguide probe-based calibration technique was used to extract the complex permittivities of the two-component (water–agar) and three-component (water-oil–agar) phantoms. The two-component phantoms were used to study the change in the dielectric properties of phantom with change in agar concentration. Water, agar, and varying proportions of oil were used to develop three-component phantom mixtures to mimic the dielectric properties of fat, fibrous and malignant breast tissues. Finally, the reflection and transmission properties of tissue-mimicking phantoms were tested using the waveguide probe calibration-based measurement setup. The difference in the S parameters between the three types of phantoms demonstrates the potential utility of D band-based data acquisition setups for tumor margin assessment applications <bold xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">.</b>

Water and hemoglobin modulated gelatin-based phantoms to spectrally mimic inflamed tissue in the validation of biomedical techniques and the modeling of microdialysis data.

.Significance: Tissue simulating phantoms are an important part of validating biomedical optical techniques. Tissue pathology in inflammation and oedema involves changes in both water and hemoglobin fractions.Aim: We present a method to create solid gelatin-based phantoms mimicking inflammation and oedema with adjustable water and hemoglobin fractions.Approach: One store-bought gelatin and one research grade gelatin were evaluated. Different water fractions were obtained by varying the water-to-gelatin ratio. Ferrous stabilized human hemoglobin or whole human blood was added as absorbers, and the stability and characteristics of each were compared. Intralipid® was used as the scatterer. All phantoms were characterized using spatial frequency domain spectroscopy.Results: The estimated water fraction varied linearly with expected values ( for the store-bought gelatin and for the research grade gelatin). Phantoms including ferrous stabilized hemoglobin stayed stable up to one day but had methemoglobin present at day 0. The phantoms with whole blood remained stable up to 3 days using the store-bought gelatin.Conclusions: A range of physiological relevant water fractions was obtained for both gelatin types, with the stability of the phantoms including hemoglobin differing between the gelatin type and hemoglobin preparation. These low-cost phantoms can incorporate other water-based chromophores and be fabricated as thin sheets to form multilayered structures.

Application of Binary Genetic Algorithm for Holographic Vascular Mimicking Phantom Reconstruction

Since medical imaging is one of the essential methods for the diagnosis and treatment of several diseases, the characterization and calibration of medical imaging systems with low-cost equipment is the most crucial issue. In this context, tissue-mimicking phantoms have long been used for this purpose. The advantage of phantoms is that, in addition to the desired size and internal properties, they can be produced in a way that best carries the characteristic properties of tissue models and can be standardized so that they can be used in imaging environments. For this reason, it is important to make low-cost phantom designs produced from materials that are easy to shape and available and to ensure that they can be imaged with high quality. In this study, digital holography and binary genetic algorithm (BGA) were used to reconstruct the images of phantoms that mimic the human vascular system produced at a low cost. The obtained results showed that BGA can be used as an alternative to the reconstruction methods commonly used in digital holography. Since BGA provides an alternative solution to obtain the image with high resolution in the reconstruction process without any image processing algorithm, it enables the diagnosis of diseases related to thin vascular structures in real-time with a reliable and non-contact method.

Gynecologic interstitial brachytherapy curriculum using a low-cost phantom with ultrasound workshop and a treatment planning workshop is effective

PURPOSE/OBJECTIVE(S)Standardized simulation training geared towards interstitial brachytherapy (IS BT) for gynecologic malignancies is lacking in radiation oncology resident education. We developed and implemented a curriculum for IS BT training with (1) lecture on equipment, workflow, and guidelines, (2) hands-on ultrasound-guided IS BT workshop, and (3) treatment planning workshop. METHODS AND MATERIALThe cost in materials of each phantom was approximately $66. After a lecture, two alternating workshops were performed. The first session consisted of a hands-on ultrasound-guided IS BT workshop with one resident imaging the phantom with a transabdominal ultrasound probe and the other resident implanting the phantom with needles. A second session consisted of a hands-on treatment planning workshop using BrachyVision and an l-Q spreadsheet with the following objectives: coverage goal, meeting D2cc constraints, and minimizing V200. The primary outcome was improvement in knowledge assessed with Likert-style questions and objective knowledge-based questions (KBQs). RESULTSFour of the seven medical residents that participated in this curriculum had prior IS BT experience. Residents reported significantly improved knowledge regarding gynecologic IS BT equipment and procedure, evaluating gynecologic anatomy using ultrasound, CT simulation, contouring, and plan review (overall median pre-session subjective score 2 (1) −(3) versus post-session score 4 (3) −(4, p < 0.01). Residents demonstrated improvement in answering KBQs correctly from 44% correct at baseline to 88% after completion of the curriculum (p < 0.01). All residents “Agree” and “Strongly Agree” the session was an effective learning experience. CONCLUSIONSResidents participating in phantom training with an ultrasound curriculum and a treatment planning session is effective for improving knowledge and skills in IS BT for radiation oncology residents.

Gynecologic Interstitial Brachytherapy Curriculum Using a Low-Cost Phantom With Ultrasound Workshop and a Treatment Planning Workshop is Feasible and Effective

<h3>Purpose/Objective(s)</h3> There is no standard simulation training geared towards interstitial brachytherapy (IS BT) for gynecologic malignancies. Most residents perform few IS cases during residency. However, IS BT is an integral part of care for locally advanced gynecologic malignancies. We developed and implemented a workshop curriculum for IS BT with: 1) lecture on equipment, workflow, and guidelines, 2) hands-on ultrasound-guided IS BT workshop, and 3) treatment planning workshop. <h3>Materials/Methods</h3> The cost of each gynecologic phantom was approximately $70; phantoms were composed of an acrylic vase cube, rigid PETG tubes, modeling clay, agar, glass microspheres, a custom molded cervix/uterus structure, and a water-filled condom to mimic the bladder. A hands-on ultrasound-guided IS BT workshop was performed with residents in two small groups, where they imaged the gynecologic phantom using a transabdominal ultrasound probe. Participants alternated roles of sonographer or brachytherapist, implanting the phantom using custom stainless-steel needles machined in-house. A second workshop with hands-on treatment planning was performed in planning software using a L-Q spreadsheet with the following objectives: coverage goal of D90, meeting D2cc constraints of bladder and rectum, and minimizing V200 to qualitatively involve a small volume. All residents filled out a pre- and post-survey with subjective (4 demographics; 12 Likert-style) and objective knowledge-based (13) questions about GYN IS-BT. Paired subjective data were compared with the Wilcoxon signed ranks test. Paired objective data were compared with the McNemar's test of paired proportions. All statistical analysis was performed with a 2-sided <i>P</i>-value at the 0.05 significance level. <h3>Results</h3> Four residents had prior IS BT experience. After the workshop, residents reported significantly improved comfort with skills and knowledge regarding GYN IS BT equipment and procedure, evaluating GYN anatomy using ultrasound, and CT Simulation, contouring, and plan review (median pre-session Likert score 2 [1-3] vs post session 3 [3-4], <i>P</i> < 0.05). The overall rate of percent correct items assessing objective radiation oncology knowledge at baseline was 44%, Following completion of the curriculum, the overall percent correct items was 88% (<i>P</i> < 0.0001). All residents "Agree" (2/7) and "Strongly Agree" (5/7) the session was an effective learning experience. Qualitative feedback primarily asked for more time with treatment planning and educational content beforehand. <h3>Conclusion</h3> Residents participating in phantom training with an ultrasound curriculum and a treatment planning session is both feasible and effective. Similar strategies should be considered to enhance and standardize radiation oncology education initiatives for gynecologic IS BT training.

Introduction of a new simple dynamic phantom for physical BOLD effect simulation.

To propose a new method of simulating the BOLD contrast using a dynamic, easy to construct and operate, low-cost physical phantom. A structure of thin pipelines passing through a gel volume was used to simulate blood vessels in human tissue. Quantitative T2*, R2* measurements were used to study the signal change of the phantom. BOLD fMRI experiments and analysis were performed to evaluate its potential use as an fMRI simulator. Experimental T2*, R2* measurements showed similar behavior with published references. BOLD contrast was successfully achieved with the proposed method. In addition, there were several proposed parameters, like the angle of the phantom relative to B0, which can easily adjust the signal change and the activation area. Coefficients of variation showed good reproducibility within a month period. Statistical t maps were produced with in-house software for the BOLD measurements. T2*maps and BOLD images confirm the potential use of this phantom as an fMRI simulator and also as a tool for studying sensitivity and specificity of BOLD sequences/algorithms.

Making a convenient, low-cost phantom with a previously unreported material for practicing ultrasound-guided procedures.

Ultrasound-guided procedures require excellent hand-eye coordination and practice. Trainees should gain this important skill with a phantom prior to performing procedures on patients. Currently available phantoms each have their own unique limitations. We propose an easily made, inexpensive, tissue-like phantom using a previously unreported material. The sonographic appearance of the phantom, with and without a 14-gauge needle, is compared with breast tissue, gelatin phantoms, and commercial phantoms. Target lesions can be produced using readily available materials. The proposed phantom is cheaper than commercial phantoms; performs better than gelatin phantoms, and is ultimately a superior practice tool for residents.

PO-1578 Low-cost 3D-printed phantom for in-air calibration of high-dose rate 192Ir brachytherapy source

PO-1578 Low-cost 3D-printed phantom for in-air calibration of high-dose rate 192Ir brachytherapy source

Creating Low-Cost Phantoms for Needle Manipulation Training in Interventional Radiology Procedures

Image-guided procedures play a critical role in the clinical practice of radiologists. Training radiology residents in these procedures, with early teaching of basic but fundamental skills, is therefore crucial to develop competence before they become autonomous and start their practice. It has been proposed in the literature that low-fidelity phantoms are appropriate to teach novice trainees. The authors propose a series of phantoms to teach the core skills necessary to perform procedures early in resident training. The phantoms described can be used to train skills necessary for performing US-guided biopsy, US-guided vascular puncture, cone-beam CT drainage, and fluoroscopy-guided lumbar puncture, as well as using the parallax effect to determine relative position at fluoroscopy. Phantoms are a valuable training tool, although it is important to consider the teaching audience when choosing or creating a model. For novices, a range of inexpensive low-fidelity gelatin-based phantoms can be used to train core skills in image-guided procedures. The online slide presentation from the RSNA Annual Meeting is available for this article. ©RSNA, 2021.

PP01 Presentation Time: 10:00 AM: Interstitial Brachytherapy Simulation Training: Manufacturing and Implanting a Low-Cost Phantom for Gynecologic Malignancies

PP01 Presentation Time: 10:00 AM: Interstitial Brachytherapy Simulation Training: Manufacturing and Implanting a Low-Cost Phantom for Gynecologic Malignancies

PP01 Presentation Time: 10:00 AM: Interstitial Brachytherapy Simulation Training: Manufacturing and Implanting a Low-Cost Phantom for Gynecologic Malignancies

Purpose/Objective(s): There is no standard simulation training geared towards interstitial brachytherapy (IS BT) for gynecologic malignancies. Many residents perform few IS cases during residency. However, IS BT is an integral part of care for locally advanced gynecologic malignancies. We manufactured a low-cost phantom for IS BT simulation training of gynecologic malignancies and used in resident training and education sessions.