scholarly journals Three-dimensional printing of patient-specific lung phantoms for CT imaging: emulating lung tissue with accurate attenuation profiles and textures

2021 ◽  
Author(s):  
Kai Mei ◽  
Michael Geagen ◽  
Leonid Roshkovan ◽  
Harold I. Litt ◽  
Grace J. Gang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Software Tool ◽  
Image Texture ◽  
Patient Specific ◽  
Ct Image ◽  
Ct Scanner ◽  
Hounsfield Units ◽  
Calibration Phantom ◽  
Attenuation Profiles ◽  
High Level

Purpose: Phantoms are a basic tool for assessing and verifying performance in CT research and clinical practice. Patient-based realistic lung phantoms accurately representing textures and densities are essential in developing and evaluating novel CT hardware and software. This study introduces PixelPrint, a 3D printing solution to create patient-based lung phantoms with accurate attenuation profiles and textures. Methods: PixelPrint, a software tool, was developed to convert Patient DICOM images directly into printer instructions (G-code). The density was modeled as the ratio of filament to voxel volume to emulate attenuation profiles for each voxel. A calibration phantom was designed to determine the mapping between filament line width and Hounsfield Units (HU) within the range of human lungs. For evaluation of PixelPrint, a phantom based on a human lung slice was manufactured and scanned with the same CT scanner and protocol used for the patient scan. Density and geometrical accuracy between phantom and patient CT data was evaluated for various anatomical features in the lung. Results: For the calibration phantom, measured mean Hounsfield units show a very high level of linear correlation with respect to the utilized filament line widths, (r > 0.999). Qualitatively, the CT image of the patient-based phantom closely resembles the original CT image both in texture and contrast levels, with clearly visible vascular and parenchymal structures. Regions-of-interest (ROIs) comparing attenuation illustrated differences below 15 HU. Manual size measurements performed by an experienced thoracic radiologist reveal a high degree of geometrical correlation of details between identical patient and phantom features, with differences smaller than the intrinsic spatial resolution of the scans. Conclusion: The present study demonstrates the feasibility of 3D printed patient-based lung phantoms with accurate organ geometry, image texture, and attenuation profiles. PixelPrint will enable applications in the research and development of CT technology, including further development in radiomics.

scholarly journals Automatically hemodynamic analysis of AAA from CT images based on deep learning and CFD approaches

2021 ◽  
Vol 2119 (1) ◽  
pp. 012069
Author(s):  
Y V Fedotova ◽  
R UI Epifanov ◽  
A A Karpenko ◽  
R I Mullyadzhanov
Keyword(s):  
Deep Learning ◽  
Aortic Rupture ◽  
Three Dimensional ◽  
Software Tool ◽  
Patient Specific ◽  
Patient Death ◽  
Computed Tomography Images ◽  
Risk Of Rupture ◽  
Serious Disease ◽  
Health Complications

Abstract Abdominal aortic aneurysm is a serious disease which course is accompanied by the development of health complications and often leads to patient death due to aortic rupture. One of the powerful methods to estimate the risk of rupture is three-dimensional patient-specific hemodynamic analysis. In this study, we develop a software tool based on deep learning and CFD methods to perform automated computational hemodynamics with patient-specific geometry reconstructed from computed tomography images.

Prosthetic Accuracy Depends on the Design of Patient-Specific Instrumentation: Results of a Retrospective Study Using Three-Dimensional Imaging

2020 ◽  
Author(s):  
Kazumasa Yamamura ◽  
Fumiaki Inori ◽  
Sadahiko Konishi
Keyword(s):  
Sagittal Plane ◽  
Three Dimensional ◽  
Computer Software ◽  
Patient Specific ◽  
Ct Image ◽  
3D Ct ◽  
Patient Specific Instrumentation ◽  
Prosthetic Alignment ◽  
Before And After ◽  
Preoperative Plan

AbstractTo determine accuracy of patient-specific instrumentation (PSI), the preoperative three-dimensional (3D) plan should be superimposed on the postoperative 3D image to compare prosthetic alignment. We aimed to compare prosthetic alignment on a preoperative 3D computed tomography (CT) plan and postoperative 3D-CT image, and evaluate the accuracy of PSI during total knee arthroplasty (TKA). Thirty consecutive knees (30 patients) who underwent TKA using PSI were retrospectively evaluated. The preoperative plan was prepared using 3D CT acquisitions of the hip, knee, and ankle joints. The postoperative 3D CT image obtained 1 week after surgery was superimposed onto the preoperative 3D plan using computer software. Differences in prosthetic alignment between the preoperative and postoperative images were measured using six parameters: coronal, sagittal, and axial alignments of femoral and tibial prostheses. Differences in prosthetic alignment greater than 3 degrees were considered outliers. Two observers performed all measurements. All parameters were repeatedly measured over a 4-week interval. This measurement method's intraobserver and interobserver reliabilities were more than 0.81 (very good). For the femoral and tibial prostheses, absolute differences between the preoperative and postoperative 3D CT images were significantly larger in the sagittal than in the coronal and axial planes (p < 0.001). The outlier rate for the sagittal alignment of femoral and tibial prostheses was significantly higher than that for the alignment of coronal and axial planes (p < 0.001). However, there were no significant differences in the range of motion (ROM) before and after TKA when comparing cases with and without outliers in the sagittal plane. Even though the present study did not reveal any issues with the ROM that depended on the presence of an outlier, accurate verification of prosthetic alignment for individual PSI models may be necessary because the designs, referenced images, and accuracy are different in each model.

Corrective Osteotomies for Complex Intra-Articular Tibial Plateau Malunions using Three-Dimensional Virtual Planning and Novel Patient-Specific Guides

2017 ◽  
Vol 31 (07) ◽  
pp. 642-648 ◽  
Author(s):  
Huixiang Wang ◽  
Simon Newman ◽  
Jiandong Wang ◽  
Qian Wang ◽  
Qiugen Wang
Keyword(s):  
Tibial Plateau ◽  
Corrective Osteotomy ◽  
Three Dimensional ◽  
3D Models ◽  
Joint Surface ◽  
Patient Specific ◽  
The Novel ◽  
Virtual Planning ◽  
Scan Data ◽  
High Level

AbstractCorrective osteotomy of intra-articular tibial plateau malunions is technically demanding for orthopaedic surgeons. The aim of our study was to evaluate the feasibility of the combination of three-dimensional (3D) virtual planning and novel patient-specific guides for assisting correction of complex intra-articular tibial plateau malunions. Six patients with posttraumatic intra-articular tibial plateau malunions were included. Preoperatively 3D models of the tibias were reconstructed using the computed tomography scan data. Virtual surgical planning was performed, and patient-specific guides for osteotomy and reduction were designed, which were then 3D printed. Intraoperatively they were applied to guide the osteotomy and reduction. After surgery, radiographs were taken to evaluate the knee joint surface. The operating surgeons were asked to complete the Likert scale questionnaire to assess their attitude to the novel technology. The guides were successfully used for guiding osteotomy correction of malunion in all patients. Postoperative radiographs showed the articular step-off was considerably reduced and the articular congruency was satisfactory in all patients. The results of the questionnaire demonstrated a high level of surgeon satisfaction and acceptance to the technology. For selective patients with complex intra-articular tibial plateau malunions, the novel technique could serve as a valuable option for guiding precise malunion correction.

scholarly journals Assessment of 11 Available Materials With Custom Three-Dimensional-Printing Patterns for the Simulation of Muscle, Fat, and Lung Hounsfield Units in Patient-Specific Phantoms

2017 ◽  
Vol 1 (1) ◽  
Author(s):  
Nikiforos Okkalidis ◽  
Chrysoula Chatzigeorgiou ◽  
Demetrios Okkalides
Keyword(s):  
Fused Deposition Modeling ◽  
Three Dimensional ◽  
Region Of Interest ◽  
Ct Images ◽  
Effective Density ◽  
Patient Specific ◽  
Hounsfield Units ◽  
Fused Deposition ◽  
3D Printers ◽  
Deposition Modeling

A couple of fused deposition modeling (FDM) three-dimensional (3D) printers using variable infill density patterns were employed to simulate human muscle, fat, and lung tissue as it is represented by Hounsfield units (HUs) in computer tomography (CT) scans. Eleven different commercial plastic filaments were assessed by measuring their mean HU on CT images of small cubes printed with different patterns. The HU values were proportional to the mean effective density of the cubes. Polylactic acid (PLA) filaments were chosen. They had good printing characteristics and acceptable HU. Such filaments obtained from two different vendors were then tested by printing two sets of cubes comprising 10 and 6 cubes with 100% to 20% and 100% to 50% infill densities, respectively. They were printed with different printing patterns named “Regular” and “Bricks,” respectively. It was found that the HU values measured on the CT images of the 3D-printed cubes were proportional to the infill density with slight differences between vendors and printers. The Regular pattern with infill densities of about 30%, 90%, and 100% were found to produce HUs equivalent to lung, fat, and muscle. This was confirmed with histograms of the respective region of interest (ROI). The assessment of popular 3D-printing materials resulted in the choice of PLA, which together with the proposed technique was found suitable for the adequate simulation of the muscle, fat, and lung HU in printed patient-specific phantoms.

Guided surgery with 3D printed device: a case report

2020 ◽  
Author(s):  
Michelle Carvalho de Sales ◽  
Rafael Maluza Flores ◽  
Julianny da Silva Guimaraes ◽  
Gustavo Vargas da Silva Salomao ◽  
Tamara Kerber Tedesco ◽  
...  
Keyword(s):  
Operating Time ◽  
Three Dimensional ◽  
Conventional Technique ◽  
Cervical Region ◽  
Mean Deviation ◽  
Apical Region ◽  
Virtual Planning ◽  
Surgical Guide ◽  
Surgical Guides ◽  
High Level

Dental surgeons need in-depth knowledge of the bone tissue status and gingival morphology of atrophic maxillae. The aim of this study is to describe preoperative virtual planning of placement of five implants and to compare the plan with the actual surgical results. Three-dimensional planning of rehabilitation using software programs enables surgical guides to be specially designed for the implant site and manufactured using 3D printing. A patient with five teeth missing was selected for this study. The patient’s maxillary region was scanned with CBCT and a cast model was produced. After virtual planning using ImplantViewer, five implants were placed using a printed surgical guide. Two weeks after the surgical procedure, the patient underwent another CBCT scan of the maxilla. Statistically significant differences were detected between the virtually planned positions and the actual positions of the implants, with a mean deviation of 0.36 mm in the cervical region and 0.7 mm in the apical region. The surgical technique used enables more accurate procedures when compared to the conventional technique. Implants can be better positioned, with a high level of predictability, reducing both operating time and patient discomfort.

scholarly journals Quantitative image analysis of microbial communities with BiofilmQ

2021 ◽  
Author(s):  
Raimo Hartmann ◽  
Hannah Jeckel ◽  
Eric Jelli ◽  
Praveen K. Singh ◽  
Sanika Vaidya ◽  
...  
Keyword(s):  
Image Analysis ◽  
Microbial Communities ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Software Tool ◽  
Image Cytometry ◽  
Quantitative Image Analysis ◽  
Space And Time ◽  
Quantitative Image ◽  
Three Dimensional Space

AbstractBiofilms are microbial communities that represent a highly abundant form of microbial life on Earth. Inside biofilms, phenotypic and genotypic variations occur in three-dimensional space and time; microscopy and quantitative image analysis are therefore crucial for elucidating their functions. Here, we present BiofilmQ—a comprehensive image cytometry software tool for the automated and high-throughput quantification, analysis and visualization of numerous biofilm-internal and whole-biofilm properties in three-dimensional space and time.

scholarly journals Numerical computation of blood flow for a patient-specific hemodialysis shunt model

2021 ◽  
Author(s):  
Surabhi Rathore ◽  
Tomoki Uda ◽  
Viet Q. H. Huynh ◽  
Hiroshi Suito ◽  
Toshitaka Watanabe ◽  
...  
Keyword(s):  
Stokes Equations ◽  
Three Dimensional ◽  
Arteriovenous Shunt ◽  
Navier Stokes ◽  
Patient Specific ◽  
Stabilized Finite Element ◽  
Computed Tomography Scanning ◽  
Outflow Boundary ◽  
Stage Renal Disease ◽  
End Stage

AbstractHemodialysis procedure is usually advisable for end-stage renal disease patients. This study is aimed at computational investigation of hemodynamical characteristics in three-dimensional arteriovenous shunt for hemodialysis, for which computed tomography scanning and phase-contrast magnetic resonance imaging are used. Several hemodynamical characteristics are presented and discussed depending on the patient-specific morphology and flow conditions including regurgitating flow from the distal artery caused by the construction of the arteriovenous shunt. A simple backflow prevention technique at an outflow boundary is presented, with stabilized finite element approaches for incompressible Navier–Stokes equations.

scholarly journals Application of subject-specific adaptive mechanical loading for bone healing in a mouse tail vertebral defect

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Angad Malhotra ◽  
Matthias Walle ◽  
Graeme R. Paul ◽  
Gisela A. Kuhn ◽  
Ralph Müller
Keyword(s):  
Mechanical Loading ◽  
Bone Defect ◽  
Bone Healing ◽  
Three Dimensional ◽  
Patient Specific ◽  
Dependent Manner ◽  
Micro Computed Tomography ◽  
Computed Tomography Images ◽  
Bone Defect Healing ◽  
Subject Specific

AbstractMethods to repair bone defects arising from trauma, resection, or disease, continue to be sought after. Cyclic mechanical loading is well established to influence bone (re)modelling activity, in which bone formation and resorption are correlated to micro-scale strain. Based on this, the application of mechanical stimulation across a bone defect could improve healing. However, if ignoring the mechanical integrity of defected bone, loading regimes have a high potential to either cause damage or be ineffective. This study explores real-time finite element (rtFE) methods that use three-dimensional structural analyses from micro-computed tomography images to estimate effective peak cyclic loads in a subject-specific and time-dependent manner. It demonstrates the concept in a cyclically loaded mouse caudal vertebral bone defect model. Using rtFE analysis combined with adaptive mechanical loading, mouse bone healing was significantly improved over non-loaded controls, with no incidence of vertebral fractures. Such rtFE-driven adaptive loading regimes demonstrated here could be relevant to clinical bone defect healing scenarios, where mechanical loading can become patient-specific and more efficacious. This is achieved by accounting for initial bone defect conditions and spatio-temporal healing, both being factors that are always unique to the patient.

Sign in / Sign up

Export Citation Format

Share Document