Considerations for Post-processing Parameters in Mixed-Method 3D Analyses

2021 ◽  
Vol 9 (4) ◽  
pp. 325-337
Author(s):  
Robert Z. Selden ◽  
Lauren N. Butaric ◽  
Kersten Bergstrom ◽  
Dennis Van Gerven
Keyword(s):  
Three Dimensional ◽  
Processing Parameters ◽  
Surface Model ◽  
Digital Repositories ◽  
Computed Tomographic ◽  
Archaeological Data ◽  
3D Data ◽  
Morphometric Analyses ◽  
Smoothing Parameters ◽  
Ct Data

ABSTRACTThe production of three-dimensional (3D) digital meshes of surface and computed tomographic (CT) data has become widespread in morphometric analyses of anthropological and archaeological data. Given that processing methods are not standardized, this leaves questions regarding the comparability of processed and digitally curated 3D datasets. The goal of this study was to identify those processing parameters that result in the most consistent fit between CT-derived meshes and a 3D surface model of the same human mandible. Eight meshes, each using unique thresholding and smoothing parameters, were compared to assess whole-object deviations, deviations along curves, and deviations between specific anatomical features on the surface model when compared with the CT scans using a suite of comparison points. Based on calculated gap distances, the mesh that thresholded at “0” with an applied smoothing technique was found to deviate least from the surface model, although it is not the most biologically accurate. Results have implications for aggregated studies that employ multimodal 3D datasets, and caution is recommended for studies that enlist 3D data from websites and digital repositories, particularly if processing parameters are unknown or derived for studies with different research foci.

scholarly journals Considerations for post-processing parameters in mixed-method 3-D analyses: A Mesolithic mandibular case study

2021 ◽  
Author(s):  
Robert Z. Selden ◽  
lauren butaric ◽  
Kersten Bergstrom ◽  
Dennis Van Gerven
Keyword(s):  
Three Dimensional ◽  
Processing Parameters ◽  
Surface Model ◽  
Digital Repositories ◽  
Computed Tomographic ◽  
Archaeological Data ◽  
Morphometric Analyses ◽  
Smoothing Parameters ◽  
Ct Data

The production of three-dimensional (3-D) digital meshes of surface and computed tomographic (CT) data has become widespread in morphometric analyses of anthropological and archaeological data. Given that processing methods are not standardised, this leaves questions regarding the comparability of processed and digitally curated 3-D datasets. The goal of this study was to identify those processing parameters that result in the most consistent fit between CT-derived meshes and a 3-D surface model of the same human mandible. Eight meshes, each using unique thresholding and smoothing parameters, were compared to assess whole-object deviations, deviations along curves, and deviations between specific anatomical features on the surface model when compared with the CT scans using a suite of \textit{comparison points}. Based on calculated gap distances, the mesh thresholded at "0" with an applied smoothing technique was found to deviate least from the surface model; although, it is not the most biologically accurate. Results have implications for aggregated studies that employ multi-modal 3-D datasets, and caution is recommended for studies that enlist 3-D data from websites and digital repositories, particularly if processing parameters are unknown or derived for studies with different research foci.

Computer-Assisted Surgery Using 3D Printed Saw Guides for Acute Correction of Antebrachial Angular Limb Deformities in Dogs

2019 ◽  
Vol 32 (03) ◽  
pp. 241-249 ◽  
Author(s):  
Andrew Worth ◽  
Katherine Crosse ◽  
Andrew Kersley
Keyword(s):  
Computer Aided Design ◽  
Sagittal Plane ◽  
Three Dimensional ◽  
Frontal Plane ◽  
Computer Assisted Surgery ◽  
Computer Assisted ◽  
Computed Tomographic ◽  
Limb Deformities ◽  
Ct Data ◽  
Saw Blade

Objective The aim of this study was to report the use of custom saw guides produced using computed tomographic imaging (CT), computer simulation and three-dimensional (3D) printing to aid surgical correction of antebrachial deformities in six dogs. Materials and Methods Antebrachial limb deformities in four small, and two large, breed dogs (seven limbs) were surgically corrected by a radial closing wedge ostectomy and ulnar osteotomy. The location and orientation of the wedge ostectomy were determined using CT data, computer-assisted planning and production of a saw guide in plastic using a 3D printer. At surgery, the guide was clamped to the surface of the radius and used to direct the oscillating saw blade. The resultant ostectomy was closed and stabilized with a bone plate. Results Five limbs healed without complications. One limb was re-operated due to a poorly resolved rotational component of the deformity. One limb required additional stabilisation with external fixation due to screw loosening. The owners of five dogs completed a Canine Orthopedic Index survey at a follow-up period of 37 to 81 months. The median preoperative score was 3.5 and the median postoperative score was 1, representing an overall positive effect of surgery. Radiographically, 5/7 limbs were corrected in the frontal plane (2/7 were under-corrected). Similarly, 5/7 limbs were corrected in the sagittal plane, and 2/7 were over-corrected in the sagittal place. Conclusions Computer-aided design and rapid prototyping technologies can be used to create saw guides to simplify one-stage corrective osteotomies of the antebrachium using internal fixation in dogs. Despite the encouraging results, accurate correction of rotational deformity was problematic and this aspect requires further development.

scholarly journals 3D immersive visualization of micro-computed tomography and XRD texture datasets

2019 ◽  
Vol 34 (2) ◽  
pp. 97-102
Author(s):  
M. A. Rodriguez ◽  
T. T. Amon ◽  
J. J. M. Griego ◽  
H. Brown-Shaklee ◽  
N. Green
Keyword(s):  
Computed Tomography ◽  
Texture Analysis ◽  
Mechanical Strain ◽  
Three Dimensional ◽  
Multidimensional Analysis ◽  
Micro Computed Tomography ◽  
X Ray ◽  
3D Data ◽  
Pole Figures ◽  
Ct Data

Advancements in computer technology have enabled three-dimensional (3D) reconstruction, data-stitching, and manipulation of 3D data obtained on X-ray imaging systems such as micro-computed tomography (μ-CT). Likewise, intuitive evaluation of these 3D datasets can be enhanced by recent advances in virtual reality (VR) hardware and software. Additionally, the generation, viewing, and manipulation of 3D X-ray diffraction datasets, such as pole figures employed for texture analysis, can also benefit from these advanced visualization techniques. We present newly-developed protocols for porting 3D data (as TIFF-stacks) into a Unity gaming software platform so that data may be toured, manipulated, and evaluated within a more-intuitive VR environment through the use of game-like controls and 3D headsets. We demonstrate this capability by rendering μ-CT data of a polymer dogbone test bar at various stages of in situ mechanical strain. An additional experiment is presented showing 3D XRD data collected on an aluminum test block with vias. These 3D XRD data for texture analysis (χ, ϕ, 2θ dimensions) enables the viewer to visually inspect 3D pole figures and detect the presence or absence of in-plane residual macrostrain. These two examples serve to illustrate the benefits of this new methodology for multidimensional analysis.

scholarly journals In-Office Guided Implant Placement for Prosthetically Driven Implant Surgery

2017 ◽  
Vol 10 (3) ◽  
pp. 246-254 ◽  
Author(s):  
Daryoush Karami ◽  
Hamid Reza Alborzinia ◽  
Reza Amid ◽  
Mahdi Kadkhodazadeh ◽  
Navid Yousefi ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Direct Observation ◽  
Three Dimensional ◽  
Hard Tissue ◽  
Tissue Thickness ◽  
Computed Tomographic ◽  
Implant Placement ◽  
Soft Tissue Thickness ◽  
Ct Data ◽  
The Cost

Application of surgical stents for implant placement via guided flapless surgery is increasing. However, high cost, need for some professional machines, and not taking into account the soft-tissue parameters have limited their application. We sought to design and introduce a technique named in-office guided implant placement (iGIP) to decrease the cost by using available devices in office and enhance the applicability of surgical stents. A customized surgical stent was fabricated based on prosthetic, soft- and hard-tissue parameters by taking into account the amount of available bone (using the computed tomographic [CT] data), soft-tissue thickness and contour (using a composite-covered radiographic stent), and position of the final crown (by diagnostic cast wax up and marking the final crown position with composite). The efficacy of iGIP, in terms of the accuracy of the three-dimensional position of the implant placed in the study cast and in patient's mouth, was confirmed by direct observation and postoperative CT. The iGIP can enhance implant placement in the prosthetically desired position in various types of edentulism. Using this technique minimizes the risk of unwanted consequences, as the soft-tissue thickness and contour are taken into account when fabricating a surgical stent.

Three-Dimensional Computed Tomographic Reconstructions of Intracranial Meningiomas

Neurosurgery ◽  
1988 ◽  
Vol 23 (5) ◽  
pp. 570-575 ◽  
Author(s):  
David J. Chalif ◽  
Craig R. Dufresne ◽  
Joseph Ransohoff ◽  
Joseph A. McCarthy
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Computer Software ◽  
Computed Tomographic ◽  
Intracranial Meningiomas ◽  
Three Dimensional Images ◽  
Ct Data ◽  
Surgical Adjunct ◽  
Relationship Of ◽  
The Relationship

Abstract In a series of four patients with intracranial meningiomas, three-dimensional computed tomographic (CT) reconstructions were a useful diagnostic and surgical adjunct. Three-dimensional images are created from standard CT data by a boundary-detecting computer software program. Three-dimensional images of tumor invading or adjacent to the bony calvarium are projected about the x, y, and z axes. Axial and sagittal sections delineate the lesions. The images created allow a surgical view of the meningiomas in three-dimensional space and demonstrate the relationship of these masses to the skull. The use of three-dimensional reconstructions in craniofacial surgery and in neurosurgery is reviewed.

Integration of Patient-Specific Paranasal Sinus Computed Tomographic Data into a Virtual Surgical Environment

2009 ◽  
Vol 23 (4) ◽  
pp. 442-447 ◽  
Author(s):  
Sachin S. Parikh ◽  
Sonny Chan ◽  
Sumit K. Agrawal ◽  
Peter H. Hwang ◽  
Curt M. Salisbury ◽  
...  
Keyword(s):  
Haptic Feedback ◽  
Three Dimensional ◽  
Sinus Surgery ◽  
Patient Specific ◽  
Imaging Data ◽  
Cross Sectional ◽  
Endoscopic Techniques ◽  
Computed Tomographic ◽  
Preoperative Ct ◽  
Ct Data

Background The advent of both high-resolution computed tomographic (CT) imaging and minimally invasive endoscopic techniques has led to revolutionary advances in sinus surgery. However, the rhinologist is left to make the conceptual jump between static cross-sectional images and the anatomy encountered intraoperatively. A three-dimensional (3D) visuo-haptic representation of the patient's anatomy may allow for enhanced preoperative planning and rehearsal, with the goal of improving outcomes, decreasing complications, and enhancing technical skills. Methods We developed a novel method of automatically constructing 3D visuo-haptic models of patients’ anatomy from preoperative CT scans for placement in a virtual surgical environment (VSE). State-of-the-art techniques were used to create a high-fidelity representation of salient bone and soft tissue anatomy and to enable manipulation of the virtual patient in a surgically meaningful manner. A modified haptic interface device drives a virtual endoscope that mimics the surgical configuration. Results The creation and manipulation of sinus anatomy from CT data appeared to provide a relevant means of exploring patient-specific anatomy. Unlike more traditional methods of interacting with multiplanar imaging data, our VSE provides the potential for a more intuitive experience that can replicate the views and access expected at surgery. The inclusion of tactile (haptic) feedback provides an additional dimension of realism. Conclusion The incorporation of patient-specific clinical CT data into a virtual surgical environment holds the potential to offer the surgeon a novel means to prepare for rhinologic procedures and offer training to residents. An automated pathway for segmentation, reconstruction, and an intuitive interface for manipulation may enable rehearsal of planned procedures.

scholarly journals Mechanical Behavior of Hydroxyapatite-Chitosan Composite: Effect of Processing Parameters

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 213
Author(s):  
Hamid Ait Said ◽  
Hassan Noukrati ◽  
Hicham Ben Youcef ◽  
Ayoub Bayoussef ◽  
Hassane Oudadesse ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Compressive Strength ◽  
Mechanical Strength ◽  
Bone Repair ◽  
Mechanical Stability ◽  
Three Dimensional ◽  
Processing Parameters ◽  
Composite Effect ◽  
Solid Liquid ◽  
The Impact

Three-dimensional hydroxyapatite-chitosan (HA-CS) composites were formulated via solid-liquid technic and freeze-drying. The prepared composites had an apatitic nature, which was demonstrated by X-ray diffraction and Infrared spectroscopy analyses. The impact of the solid/liquid (S/L) ratio and the content and the molecular weight of the polymer on the composite mechanical strength was investigated. An increase in the S/L ratio from 0.5 to 1 resulted in an increase in the compressive strength for HA-CSL (CS low molecular weight: CSL) from 0.08 ± 0.02 to 1.95 ± 0.39 MPa and from 0.3 ± 0.06 to 2.40 ± 0.51 MPa for the HA-CSM (CS medium molecular weight: CSM). Moreover, the increase in the amount (1 to 5 wt%) and the molecular weight of the polymer increased the mechanical strength of the composite. The highest compressive strength value (up to 2.40 ± 0.51 MPa) was obtained for HA-CSM (5 wt% of CS) formulated at an S/L of 1. The dissolution tests of the HA-CS composites confirmed their cohesion and mechanical stability in an aqueous solution. Both polymer and apatite are assumed to work together, giving the synergism needed to make effective cylindrical composites, and could serve as a promising candidate for bone repair in the orthopedic field.

scholarly journals Imaging in Propeller Flap Surgery

2020 ◽  
Vol 34 (03) ◽  
pp. 145-151
Author(s):  
Shimpei Ono ◽  
Hiroyuki Ohi ◽  
Rei Ogawa
Keyword(s):  
Low Cost ◽  
Three Dimensional ◽  
Duplex Sonography ◽  
Computed Tomographic Angiography ◽  
Ease Of Use ◽  
Computed Tomographic ◽  
Imaging Tool ◽  
Preoperative Mapping ◽  
Flap Design ◽  
Tomographic Angiography

AbstractSince propeller flaps are elevated as island flaps and most often nourished by a single perforator nearby the defect, it is challenging to change the flap design intraoperatively when a reliable perforator cannot be found where expected to exist. Thus, accurate preoperative mapping of perforators is essential in the safe planning of propeller flaps. Various methods have been reported so far: (1) handheld acoustic Doppler sonography (ADS), (2) color duplex sonography (CDS), (3) perforator computed tomographic angiography (P-CTA), and (4) magnetic resonance angiography (MRA). To facilitate the preoperative perforator assessment, P-CTA is currently considered as the gold standard imaging tool in revealing the three-dimensional anatomical details of perforators precisely. Nevertheless, ADS remains the most widely used tool due to its low cost, faster learning, and ease of use despite an undesirable number of false-positive results. CDS can provide hemodynamic characteristics of the perforator and is a valid and safer alternative particularly in patients in whom ionizing radiation and/or contrast exposure should be limited. Although MRA is less accurate in detecting smaller perforators of caliber less than 1.0 mm and the intramuscular course of perforators at the present time, MRA is expected to improve in the future due to the recent developments in technology, making it as accurate as P-CTA. Moreover, it provides the advantage of being radiation-free with fewer contrast reactions.

scholarly journals How Effective Is the Green Development Policy of China’s Yangtze River Economic Belt? A Quantitative Evaluation Based on the PMC-Index Model

2021 ◽  
Vol 18 (14) ◽  
pp. 7676
Author(s):  
Shengli Dai ◽  
Weimin Zhang ◽  
Jiamin Zong ◽  
Yingying Wang ◽  
Ge Wang
Keyword(s):  
Yangtze River ◽  
Three Dimensional ◽  
Local Area ◽  
Surface Model ◽  
Policy Effectiveness ◽  
Index Model ◽  
Advantages And Disadvantages ◽  
Green Development ◽  
Development Policies ◽  
Policy Texts

Although many countries around the world, especially China, highlight the strategy of green development, there has been little research evaluating the effectiveness of green development policies in local area. This study explores 16 policy texts with the theme of green development in the Yangtze River Economic Belt in China. Using the Policy Modeling Consistency Index (PMC-Index) model, the paper establishes a multi-input–output policy table and scientifically and systematically evaluates these policies. The results show that the average PMC index of the 16 policy texts is 6.83, indicating a high overall quality of policy texts. The index identifies two states of policy effectiveness as being good and excellent; 50% of the total texts fall into these categories and do not fall into the category of having a low level of policy effectiveness. Five indicators, including policy timeliness, social benefits, policy audience scope, and incentives and constraints, significantly impact the PMC-Index of the policy. Six representative policy samples were selected and analyzed. The advantages and disadvantages of the policy can be more fully understood by the degree of depression of the PMC’s three-dimensional curved surface (PMC-Surface) model. Finally, the paper provides theoretical recommendations for the optimization of the green development policies.

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