Patient‐specific anatomical models for radioiodine dosimetry in treatment of hyperthyroidism: is it necessary?

2020 ◽  
Vol 47 (10) ◽  
pp. 5357-5365
Author(s):  
Susan Khalili ◽  
Hashem Miri‐Hakimabad ◽  
Elie Hoseinian‐Azghadi
2020 ◽  
Vol 7 (1) ◽  
pp. 7 ◽  
Author(s):  
Elisa Mussi ◽  
Federico Mussa ◽  
Chiara Santarelli ◽  
Mirko Scagnet ◽  
Francesca Uccheddu ◽  
...  

In brain tumor surgery, an appropriate and careful surgical planning process is crucial for surgeons and can determine the success or failure of the surgery. A deep comprehension of spatial relationships between tumor borders and surrounding healthy tissues enables accurate surgical planning that leads to the identification of the optimal and patient-specific surgical strategy. A physical replica of the region of interest is a valuable aid for preoperative planning and simulation, allowing the physician to directly handle the patient’s anatomy and easily study the volumes involved in the surgery. In the literature, different anatomical models, produced with 3D technologies, are reported and several methodologies were proposed. Many of them share the idea that the employment of 3D printing technologies to produce anatomical models can be introduced into standard clinical practice since 3D printing is now considered to be a mature technology. Therefore, the main aim of the paper is to take into account the literature best practices and to describe the current workflow and methodology used to standardize the pre-operative virtual and physical simulation in neurosurgery. The main aim is also to introduce these practices and standards to neurosurgeons and clinical engineers interested in learning and implementing cost-effective in-house preoperative surgical planning processes. To assess the validity of the proposed scheme, four clinical cases of preoperative planning of brain cancer surgery are reported and discussed. Our preliminary results showed that the proposed methodology can be applied effectively in the neurosurgical clinical practice both in terms of affordability and in terms of simulation realism and efficacy.


2019 ◽  
Vol 160 (50) ◽  
pp. 1967-1975 ◽  
Author(s):  
János Imre Barabás ◽  
Áron Kristóf Ghimessy ◽  
Ferenc Rényi-Vámos ◽  
Ákos Kocsis ◽  
László Agócs ◽  
...  

Abstract: Use of 3D planning and 3D printing is expanding in healthcare. One of the common applications is the creation of anatomical models for the surgical procedure from DICOM files. These patient-specific models are used for multiple purposes, including visualization of complex anatomical situations, simulation of surgical procedures, patient education and facilitating communication between the different disciplines during clinical case discussions. Cardiac and thoracic surgical applications of this technology development include the use of patient-specific 3D models for exploration of ventricle and aorta function and surgical procedural planning in oncology. The 3D virtual and printed models provide a new visualization perspective for the surgeons and more efficient communication between the different clinical disciplines. The 3D project was started at the Semmelweis University with the cooperation of the Thoracic Surgery Department of the National Institute of Oncology in 2018. The authors want to share their experiences in 3D designed medical tools. Orv Hetil. 2019; 160(50): 1967–1975.


2019 ◽  
Vol 13 (3) ◽  
Author(s):  
Kay S. Hung ◽  
Michael J. Paulsen ◽  
Hanjay Wang ◽  
Camille Hironaka ◽  
Y. Joseph Woo

In recent years, advances in medical imaging and three-dimensional (3D) additive manufacturing techniques have increased the use of 3D-printed anatomical models for surgical planning, device design and testing, customization of prostheses, and medical education. Using 3D-printing technology, we generated patient-specific models of mitral valves from their pre-operative cardiac imaging data and utilized these custom models to educate patients about their anatomy, disease, and treatment. Clinical 3D transthoracic and transesophageal echocardiography images were acquired from patients referred for mitral valve repair surgery and segmented using 3D modeling software. Patient-specific mitral valves were 3D-printed using a flexible polymer material to mimic the precise geometry and tissue texture of the relevant anatomy. 3D models were presented to patients at their pre-operative clinic visit and patient education was performed using either the 3D model or the standard anatomic illustrations. Afterward, patients completed questionnaires assessing knowledge and satisfaction. Responses were calculated based on a 1–5 Likert scale and analyzed using a nonparametric Mann–Whitney test. Twelve patients were presented with a patient-specific 3D-printed mitral valve model in addition to standard education materials and twelve patients were presented with only standard educational materials. The mean survey scores were 64.2 (±1.7) and 60.1 (±5.9), respectively (p = 0.008). The use of patient-specific anatomical models positively impacts patient education and satisfaction, and is a feasible method to open new opportunities in precision medicine.


Fluids ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 60 ◽  
Author(s):  
Ernest Lo ◽  
Leon Menezes ◽  
Ryo Torii

Background: Calculation of fractional flow reserve (FFR) using computed tomography (CT)-based 3D anatomical models and computational fluid dynamics (CFD) has become a common method to non-invasively assess the functional severity of atherosclerotic narrowing in coronary arteries. We examined the impact of various inflow boundary conditions on computation of FFR to shed light on the requirements for inflow boundary conditions to ensure model representation. Methods: Three-dimensional anatomical models of coronary arteries for four patients with mild to severe stenosis were reconstructed from CT images. FFR and its commonly-used alternatives were derived using the models and CFD. A combination of four types of inflow boundary conditions (BC) was employed: pulsatile, steady, patient-specific and population average. Results: The maximum difference of FFR between pulsatile and steady inflow conditions was 0.02 (2.4%), approximately at a level similar to a reported uncertainty level of clinical FFR measurement (3–4%). The flow with steady BC appeared to represent well the diastolic phase of pulsatile flow, where FFR is measured. Though the difference between patient-specific and population average BCs affected the flow more, the maximum discrepancy of FFR was 0.07 (8.3%), despite the patient-specific inflow of one patient being nearly twice as the population average. Conclusions: In the patients investigated, the type of inflow boundary condition, especially flow pulsatility, does not have a significant impact on computed FFRs in narrowed coronary arteries.


2021 ◽  
Author(s):  
◽  
Ana Morris

<p>Novel technologies that produce medical models which are synthetic equivalents to human tissue may forever change the way human anatomy and medicine are explored. Medical modelling using a bitmap-based additive manufacturing workflow offers exciting opportunities for medical education, informed consent practices, skills acquisition, pre-operative planning and surgical simulation. Moving medical data from the 2D-world to tactile, highly detailed 3D-printed anatomical models may significantly change how we comprehend the body; revamping everything – from medical education to clinical practice.  Research Problem The existing workflow for producing patient-specific anatomical models from biomedical imaging data involves image thresholding and iso-surface extraction techniques that result in surface meshes (also known as objects or parts). This process restricts shape specification to one colour and density, limiting material blending and resulting in anatomically inequivalent medical models. So, how can the use of 3D-printing go beyond static anatomical replication? Imagine pulling back the layers of tissue to reveal the complexity of a procedure, allowing a family to understand and discuss their diagnosis. Overcoming the disadvantages of static medical models could be a breakthrough in the areas of medical communication and simulation. Currently, patient specific models are either rigid or mesh-based and, therefore, are not equivalents of physiology.  Research Aim The aim of this research is to create tangible and visually compelling patient-specific prototypes of human anatomy, offering an insight into the capabilities of new bitmap-based 3D-printing technology. It proposes that full colour, multi-property, voxel-based 3D-printing can emulate physiology, creating a new format of visual and physical medical communication.  Data Collection and Procedure For this study, biomedical imaging data was converted into multi-property 3D-printed synthetic anatomy by bypassing the conversion steps of traditional segmentation. Bitmap-based 3D-printing allows for the precise control over every 14-micron material droplet or “voxel”.  Control over each voxel involves a process of sending bitmap images to a high-resolution and multi-property 3D-printer. Bitmap-based 3D-printed synthetic medical models – which mimicked the colour and density of human anatomy – were successfully produced.  Findings This research presented a novel and streamlined bitmap-based medical modelling workflow with the potential to save manufacturing time and labour cost. Moreover, this workflow produced highly accurate models with graduated densities, translucency, colour and flexion – overcoming complexities that arise due to our body’s opaqueness. The presented workflow may serve as an incentive for others to investigate bitmap-based 3D-printing workflows for different manufacturing applications.</p>


2021 ◽  
Vol 10 (16) ◽  
pp. 3509
Author(s):  
Guido R. Sigron ◽  
Marina Barba ◽  
Frédérique Chammartin ◽  
Bilal Msallem ◽  
Britt-Isabelle Berg ◽  
...  

The present study aimed to analyze if a preformed “hybrid” patient-specific orbital mesh provides a more accurate reconstruction of the orbital floor and a better functional outcome than a standardized, intraoperatively adapted titanium implant. Thirty patients who had undergone surgical reconstruction for isolated, unilateral orbital floor fractures between May 2016 and November 2018 were included in this study. Of these patients, 13 were treated conventionally by intraoperative adjustment of a standardized titanium mesh based on assessing the fracture’s shape and extent. For the other 17 patients, an individual three-dimensional (3D) anatomical model of the orbit was fabricated with an in-house 3D-printer. This model was used as a template to create a so-called “hybrid” patient-specific titanium implant by preforming the titanium mesh before surgery. The functional and cosmetic outcome in terms of diplopia, enophthalmos, ocular motility, and sensory disturbance trended better when “hybrid” patient-specific titanium meshes were used but with statistically non-significant differences. The 3D-printed anatomical models mirroring the unaffected orbit did not delay the surgery’s timepoint. Nonetheless, it significantly reduced the surgery duration compared to the traditional method (58.9 (SD: 20.1) min versus 94.8 (SD: 33.0) min, p-value = 0.003). This study shows that using 3D-printed anatomical models as a supporting tool allows precise and less time-consuming orbital reconstructions with clinical benefits.


2020 ◽  
Author(s):  
Joshua Vic Chen ◽  
Alan BC Dang ◽  
Alexis Dang

Abstract Background3D printed patient-specific anatomical models have been applied clinically to orthopaedic care for surgical planning and patient education. The estimated cost and print time per model for 3D printers have not yet been compared with clinically representative models across multiple printing technologies. This study investigates six commercially-available 3D printers: Prusa i3 MK3S, Formlabs Form 2, Formlabs Form 3, LulzBot TAZ 6, Stratasys F370, and Stratasys J750 Digital Anatomy.MethodsSeven representative orthopaedic standard tessellation models derived from CT scans were imported into the respective slicing software for each 3D printer. For each printer and corresponding print setting, the slicing software provides a print time and material use estimate. Material quantity was used to calculate estimated model cost. Print settings investigated were infill percentage, layer height, and model orientation on the print bed. The slicing software investigated are Cura LulzBot Edition 3.6.20, GrabCAD Print 1.43, PreForm 3.4.6, and PrusaSlicer 2.2.0.ResultsThe effect of changing infill between 15% and 20% on estimated print time and material use was negligible. Orientation of the model has considerable impact on time and cost with worst-case differences being as much as 39.30% added print time and 34.56% added costs. Averaged across all investigated settings, horizontal model orientation on the print bed minimizes estimated print time for all 3D printers, while vertical model orientation minimizes cost with the exception of Stratasys J750 Digital Anatomy, in which horizontal orientation also minimized cost. Decreasing layer height for all investigated printers increased estimated print time and decreased estimated cost with the exception of Stratasys F370, in which cost increased. The difference in material cost was two orders of magnitude between the least and most-expensive printers. The difference in build rate (cm3/min) was one order of magnitude between the fastest and slowest printers.ConclusionsAll investigated 3D printers in this study have the potential for clinical utility. Print time and print cost are dependent on orientation of anatomy and the printers and settings selected. Cost-effective clinical 3D printing of anatomic models should consider an appropriate printer for the complexity of the anatomy and the experience of the printer technicians.


2020 ◽  
Vol 27 (7) ◽  
pp. S71-S72
Author(s):  
T. Flaxman ◽  
C.M. Cooke ◽  
A. Sheikh ◽  
O. Miguel ◽  
L. Chepelev ◽  
...  

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