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In this paper, we propose a machine learning approach for detecting superficial defects in metal surfaces using point cloud data. We compare the performance of two popular deep learning architectures, multilayer perceptron networks (MLPs) and fully convolutional networks (FCNs), with varying feature sets. Our results show that FCNs (F1=0.94) outperformed MLPs (F1=0.52) in terms of precision, recall, and F1-score. We found that transfer learning with pre-trained models can improve performance when the amount of available data is limited. Our study highlights the importance of considering the amount and quality of training data in developing machine learning models for defect detection in industrial settings with 3D images. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this clinical study was to compare the accuracy of intraoral scan system (IOS) with prefabricated aids and stereophotogrammetry (SPG) compared with open tray implant impression (OI) for complete‐arch implant‐supported fixed dental prostheses (CIFDP). Materials and methods: Patients needing CIFDP were enrolled in this study. OI, reference standard, IOS with prefabricated aids, and SPG were performed for each patient. Distance and angle deviations between all pairs of abutment analogs, root mean square (RMS) errors between the aligned test and reference model, and chairside time were measured. The effect of inter‐abutment distance, jaw (maxilla or mandible), number of implants, and arch length on deviations was analyzed. The mixed effect model was applied to analyze deviations and RMS errors. Results: Fifteen consecutive individuals (6 females and 9 males, 47–77 years old) with 22 arches (9 upper and 13 lower jaws) and 115 implants were included. There was no significant difference in distance deviation comparing SPG and IOS with OI (p >.05). IOS showed a significantly greater angle deviation and RMS errors than SPG (median 0.40° vs. 0.31°, 69 μm vs. 45 μm, p <.01). The inter‐abutment distance was negatively correlated with the accuracy of SPG and IOS (p <.05). The chairside time for IOS, SPG, and OI was 10.49 ± 3.50, 14.71 ± 2.86, and 20.20 ± 3.01 min, respectively (p <.01). Conclusions: The accuracy of SPG and IOS with prefabricated aids was comparable. IOS was the most efficient workflow. [ABSTRACT FROM AUTHOR]

Accurate geometric modeling of blood vessel lumen from 3D images is crucial for vessel quantification as part of the diagnosis, treatment, and monitoring of vascular diseases. Our method, unlike other approaches which assume a circular or elliptical vessel cross-section, employs parametric B-splines combined with image formation system equations to accurately localize the highly curved lumen boundaries. This approach avoids the need for image segmentation, which may reduce the localization accuracy due to spatial discretization. We demonstrate that the model parameters can be reliably identified by a feedforward neural network which, driven by the cross-section images, predicts the parameter values many times faster than a reference least-squares (LS) model fitting algorithm. We present and discuss two example applications, modeling the lower extremities of artery–vein complexes visualized in steady-state contrast-enhanced magnetic resonance images (MRI) and the coronary arteries pictured in computed tomography angiograms (CTA). Beyond applications in medical diagnosis, blood-flow simulation and vessel-phantom design, the method can serve as a tool for automated annotation of image datasets to train machine-learning algorithms. [ABSTRACT FROM AUTHOR]

Hand gesture recognition is important in human-computer interaction with wide applications in many fields. Different from common hand gesture recognition based on 2D images acquired from RGB camera, the utilization of 3D images provides additional spatial information about the target and attracts more and more attention in hand gesture recognition. However, most 3D images for hand gesture recognition are based on depth maps, which only take the distance information as a channel of 2D images, without taking full use of the 3D information. Besides, greater data volume of 3D images brings challenges to the arithmetic facility of hand gesture recognition. Here, we proposed a point cloud based method for hand gesture recognition. To fully use the 3D information, plane points for template matching were extracted based on their normal distributions, which leads to the average recognition rate over 97%. Pre-classification was implemented to ensure a high-efficient recognition without additional requirements for the computer. The proposed method may provide approach for accurate and efficient hand gesture recognition based on 3D images. [ABSTRACT FROM AUTHOR]

Analytic signal is a useful mathematical tool. It separates qualitative and quantitative information of a signal in form of the local phase and local amplitude. Clifford Fourier transform (CFT) plays a vital role in the representation of multidimensional signals. By generalizing the CFT to Clifford linear canonical transform (CLCT), we present a new type of Clifford biquaternionic analytic signal. Due to the advantages of more freedom, the envelop detection problems of 3D images, with the help of this new analytic signal, can get a better visual appearance. Synthesis examples are presented to demonstrate these advantages. [ABSTRACT FROM AUTHOR]

Background: Femoral antetorsion in uncemented hip replacement hardly can be modified and the restoration of the anatomic anteversion might be difficult with standard stems. We compared femoral anteversion restoration of a generic straight stem with a proximally fixed anatomic stem that included a dual sagittal curvature and a proximal torsion. It was hypothesised that the restoration of the anteversion was more accurate with the anatomic stem. Patients and methods: In this comparative study data were collected prospectively of 80 consecutive patients with total hip arthroplasty for primary osteoarthritis. In the first 40 patients (Group I) a cementless proximally fixed anatomic stem with 15° antetorsion of the shaft and a dual sagittal curvature was used. Its design was based on a database of 3D CT images of 600 hips. For comparison a cementless generic straight double-tapered stem was implanted in the next 40 patients (Group II). All operations were performed by one experienced surgeon. All patients had a preoperative 3D planning. A low-dose CT scan was performed at 3 months postoperatively to determine the postoperative stem anteversion. Results: The demographics were similar in both groups. In group I the mean postoperative femoral anteversion was similar to the preoperative one (22.1° ± 10.2° vs. 20.4° ± 9°; p = 0.2). In Group II, the mean postoperative femoral anteversion was lower (12.9° ± 10.8°, vs. 18.3° ± 12°; p = 0.02). Conclusions: Uncemented standard femoral stems tend to reduce femoral anteversion. The used anatomic stem restored femoral anteversion better. The clinical impact of this finding has to be proven. [ABSTRACT FROM AUTHOR]

Batu Caves is an isolated limestone massif located in the outskirts of north Kuala Lumpur. Dark Cave supports significant species endemism with its diverse habitats. Nine reported caverns have been mapped using conventional speleological methods. The selection of Dark Cave as a Conservation Site was able to limit the number of visitors, preventing intrusive surveys and making non-intrusive methods such as Light Detection and Ranging (LIDAR) scanning useful. In this study, the interior of the cave was mapped using LIDAR to produce a 3D model of the caverns. The results showed that the LIDAR model produced a more accurate representation of Dark Cave than the conventional 2D map. Features such as cavern's dimension, bat roosting locations, and man-made structures revealed in this 3D model are novel from previous conventional maps. Integration of LIDAR-acousticvisualisation survey methods further confirms four bat species (Taphozous melanopogon, Hipposideros diadema, Eonycteris spelaea, Rousettus leschenaultii) roosting in the Dark Cave. T. melanopogon roosts at the brightest part of Dark Cave, while colonies of H. diadema were only found in the pitch-dark areas of Dark Cave. These outcomes produced a more accurate map as reference to scientists and management authority can use it in important conservation decision-making in the future. [ABSTRACT FROM AUTHOR]

Holography is an optical (interferometric-diffractive) technique that allows the recording and reconstruction of 3D images of objects, as a hologram carries the intensity and phase information of a 'holographed' object. For its study and realization, conventional, theoretical and experimental optical tools are applied. On the other hand, the evolution of computers in data processing and storage, has enabled the viability of computational holograms, the so-called computer generated holograms (CGH). Currently, the experimental implementation of CGHs is done through new opto-electronic devices such as spatial light modulators (SLM), high resolution CCDs cameras, in addition to new photosensitive materials; thus allowing the recording and optical reconstruction of wavefronts of three-dimensional objects and special optical beams. Thus, the purpose of these works is to present and make available to the academic, scientific and other areas of knowledge our studies and algorithms (routines) of computational holographic generation in an accessible and didactic way. Specifically, in this first article, the purpose is to study computer generated holography (CGH) from simplified algorithms (software) of virtual 3D images; as well as, to present simulation results of construction (recording) and numerical reconstruction (reading) of CGHs from simple 2D and 3D images using MATLAB. These present interesting possibilities for experimental realization through their optical reconstruction (reproduction) using SLMs devices to obtain 3D images. [ABSTRACT FROM AUTHOR]

Deep learning (DL) based semantic segmentation methods have achieved excellent performance in biomedical image segmentation, producing high quality probability maps to allow extraction of rich instance information to facilitate good instance segmentation. While numerous efforts were put into developing new DL semantic segmentation models, less attention was paid to a key issue of how to effectively explore their probability maps to attain the best possible instance segmentation. We observe that probability maps by DL semantic segmentation models can be used to generate many possible instance candidates, and accurate instance segmentation can be achieved by selecting from them a set of “optimized” candidates as output instances. Further, the generated instance candidates form a well-behaved hierarchical structure (a forest), which allows selecting instances in an optimized manner. Hence, we propose a novel framework, called hierarchical earth mover’s distance (H-EMD), for instance segmentation in biomedical 2D+time videos and 3D images, which judiciously incorporates consistent instance selection with semantic-segmentation-generated probability maps. H-EMD contains two main stages: (1) instance candidate generation: capturing instance-structured information in probability maps by generating many instance candidates in a forest structure; (2) instance candidate selection: selecting instances from the candidate set for final instance segmentation. We formulate a key instance selection problem on the instance candidate forest as an optimization problem based on the earth mover’s distance (EMD), and solve it by integer linear programming. Extensive experiments on eight biomedical video or 3D datasets demonstrate that H-EMD consistently boosts DL semantic segmentation models and is highly competitive with state-of-the-art methods. [ABSTRACT FROM AUTHOR]

This paper presents a high-performance 2D-to-3D conversion algorithm technique and its VLSI architecture design for natural scenes. In this study, the depth map was generated based on the horizontal dividing line concept. Also, the dividing line was estimated by obvious color difference on the local region, and the current dividing line was a demarcation from the maximum value to the minimum one for the depth map. A Depth Based Image Rendering technology was employed to generate stereoscopic images according to the image channel of the depth map. Based on the proposed algorithm, a real-time VLSI architecture is presented. Also, for the purpose of cost efficiency, a module-based hardware consisting of a timing schedule control should be designed. The multiplications and divisions of the algorithm can be minimized by circuit design, and so this helps reduce the complexity of this system. Only one frame memory is required to generate real-time 3D images using the depth map. The depth map can be immediately calculated by referring to the location of dividing lines, which can reduce the storage size and I/O bandwidth. The circuit is simulated and verified by one FPGA chip. The critical path is at the multiplex and one flip-flop, and the maximum clock rate can achieve 205 MHz. To be VGA compatible, the stereoscopic RGB pixels can be outputted in parallel per clock to the interface. The overall maximum data rates of the proposed 3D conversion chip can achieve 610 M bytes per second. This can meet the real-time HD requirement. [ABSTRACT FROM AUTHOR]

Most commercially successful face recognition systems combine information from multiple sensors (2D and 3D, visible light and infrared, etc.) to achieve reliable recognition in various environments. When only a single sensor is available, the robustness as well as efficacy of the recognition process suffer. In this paper, we focus on face recognition using images captured by a single 3D sensor and propose a method based on the use of region covariance matrixes and Gaussian mixture models (GMMs). All steps of the proposed framework are automated, and no metadata, such as pre-annotated eye, nose, or mouth positions is required, while only a very simple clustering-based face detection is performed. The framework computes a set of region covariance descriptors from local regions of different face image representations and then uses the unscented transform to derive low-dimensional feature vectors, which are finally modeled by GMMs. In the last step, a support vector machine classification scheme is used to make a decision about the identity of the input 3D facial image. The proposed framework has several desirable characteristics, such as an inherent mechanism for data fusion/integration (through the region covariance matrixes), the ability to explore facial images at different levels of locality, and the ability to integrate a domain-specific prior knowledge into the modeling procedure. Several normalization techniques are incorporated into the proposed framework to further improve performance. Extensive experiments are performed on three prominent databases (FRGC v2, CASIA, and UMB-DB) yielding competitive results. [ABSTRACT FROM AUTHOR]

Glaucoma is as an abnormality of the optic system that alters the patient's vision, causing damage to the nervous system and potentially increasing intraocular pressure. Early detection is essential in glaucoma – a progressive disease – in order to initiate preventive treatment and thus avoid total vision loss in patients. Efficient glaucoma diagnosis is expensive and time consuming. Considering these aspects, computer vision techniques have been developed to obtain a rapid and cost-effective diagnosis. This paper presents a new method of classification for glaucomatous and healthy background images of the eye. Here, we propose the use of a three-dimensional convolutional neural network (3DCNN) applied to volumes constructed from a transformation, which converts two-dimensional (2D) background images of the eye. The proposed method showed favorable results, reaching 96.4% accuracy, 100% sensitivity, 93.02% specificity, a 0.965 area under the curve (AUC), and a 0.928 Kappa. [ABSTRACT FROM AUTHOR]

Stereoscopic three‐dimensional (S3D) displays can present a different image to each eye and therefore can convey depth cues and enhance image appearance. However, many people often feel discomfort when the difference between two retinas exceeds a certain amount. There are many factors that affect the visual comfort of S3D displays, and there is no standard for evaluating the visual comfort of 3D contents. In this paper, we conduct an experiment to evaluate the visual discomfort caused by hue asymmetries in 3D images. In particular, it examines how the hue difference factor affects the visual comfort in two types of 3D images: natural images and computer‐generated images. By manipulating the hue asymmetries of 3D images in the CIE LAB color space, the visual comfort was measured subjectively at nine different hue levels. The results of the experiment showed that the visual comfort decreases as the hue difference increases on both image types. We found that natural images are more discomfortable than computer‐generated images at the same hue difference level. It may be due to the fact that natural images have more detailed features. Based on Weber–Fechner's Law, an objective mathematical model was fitted out. The model predicts that the maximum value of hue difference for comfortable watching is about 76.3°. This is a large tolerance range, and it provides the basis for the application that the surface appearance of an object can be simulated easily by using binocular color difference on 3D display devices. [ABSTRACT FROM AUTHOR]

Structured light scanning is a noninvasive, accurate, and cost‐effective 3D imaging technique, but due to reflection issues is yet to be utilized for tool mark analysis on fresh bone. During imaging, reflection from shiny surfaces, such as greasy bone, disrupts image formation. This study tested the David SLS‐1 scanner's ability to image saw marks and explored six strategies to reduce reflection by [1] dulling the surface or [2] altering the projected light. The surface was dulled by freezing, talcum powder, dulling spray, or compressed air. The projected light was altered with a diffuser or limited to single pattern‐coded. Results demonstrated that the resolution was insufficient for capturing minute details of striae. All six tests failed to reduce reflection sufficiently to produce complete images, but projecting vertical pattern‐coded light showed the most promise. Future research is required concentrating on enhancing resolution and exploring the role of pattern‐coded light in reducing reflection. [ABSTRACT FROM AUTHOR]

Highlights • Results of the μCT analysis were associated with hydraulic measurements. • μCT allowed a detailed analysis of soil morphological and geometrical parameters. • Forest presented the highest macroporosity and connectivity in the 0.05-0.10 m layer. • No-tillage system connectivity was larger than conventional tillage for 0.05-0.10 m layer. • Macroporosity presented great influence on the saturated hydraulic conductivity. Abstract The sustainability and efficiency of crop production are sometimes dependent on the adopted tillage system. In Brazil, conservation systems such as no-tillage (NT) have been adopted as an alternative to conventional tillage (CT) method. Conservation tillage systems usually tend to minimize soil losses, water runoff, preserve soil moisture and reduce the disruption of the soil structure. Nevertheless, the influence of these managements in the soil porous system, in the micrometric point of view, is not presented in most of the published literature. Considering the importance of pores for the proper functioning of the soil, the main objective of this study was to analyze the effect of long-term NT and CT systems, in comparison to non-managed soil maintained under secondary forest (F) conditions on the pore system of a clay soil, using 3D X-ray computed tomography (μCT) images. To achieve this goal, 3D μCT images were obtained from samples of the surface soil (0.05-0.10 m and 0.10-0.15 m). Morphological attributes such as: macroporosity (MAP), number of macropores (NMAP), shape of pores, tortuosity (τ) and connectivity (C), estimated based on the Euler-Poincaré characteristic (EPC), were employed to characterize the soil porous system. In addition, saturated hydraulic conductivity (K s) and soil water retention curve (SWRC) were analyzed. The forest was characterized by the highest MAP. However, when comparing the tillage systems, the CT MAP was larger than that of NT. K s showed the same trends, which indicates that K s was directly influenced by MAP. However, SWRC analyses showed a greater volume fraction of mesopores and micropores under NT than under CT. The macropore size distribution reveals that large well-connected macropores (volume >1000 mm3) were responsible for the major contribution to MAP. However, the highest contribution to NMAP was given by macropores with volume up to 0.1 mm3. Tortuosity results indicate less sinuous pores for F, when compared to CT and NT. EPC results present better connectivity of pores in the shallow layer 0.05-0.10 m for F, while the opposite was observed for CT. The present research showed that from 3D μCT images, associated with results of hydraulic properties, it is possible to characterize the macroporous system of undisturbed samples. Research like this is important to infer about the impacts of management systems on soil. [ABSTRACT FROM AUTHOR]

Highlights • An automatic tool (Morpho3D) was developed to register and analyze 3D body shapes of large animals. • Correlations between Morpho3D and manual measurements on morphological traits are high. • Reproducibility and repeatability variation coefficients are lower than 4%. • It will offer opportunities to determine animal body volume and surface. Abstract Monitoring the growth and body condition of cows is essential for optimal management of modern dairy farms. However, monitoring is rarely performed on commercial farms. Modern technologies based on three-dimensional (3D) shape analysis could address this problem. The objective of the present study was to test and validate tools that can record and analyze 3D body shapes of animals. On 30 Holstein dairy cows, wither height (WH), heart girth (HG), chest depth (CD), hip width (HW), backside width (BaW) and ischial width (IW) were manually measured. These manual measurements were compared to those measured with a scanner (Morpho3D) that provided 3D images of the entire cow body. Correlations between manual and Morpho3D measurements were high: 0.89 for CD, 0.82 for HW, 0.78 for HG, 0.76 for BaW, 0.63 for IW and 0.62 for WH. The mean coefficient of variation of reproducibility for Morpho3D was 2.8%. Future development can provide new opportunities for dairy herd management based on determining animal body volume and surface area. [ABSTRACT FROM AUTHOR]

Surface correlation functions are extremely useful descriptors of interfaces and in this role can be used in material science, rock and soil physics, food engineering and other numerous areas. However, their widespread usage was hampered by insufficiently robust computation methodologies. In this contribution we elaborate on recent works in surface function evaluation and present a novel exact algorithm to compute surface–surface (F s s) and surface–surface–surface (F s s s) functions for smooth boundary sets without discretization. This allows us to test digital computational approach on geometries beyond those available as analytical solutions. Moreover, we propose a better edge detection filter that allowed to improve the quality of assessment of surface correlation functions, both surface–surface (F s s) and surface-void (F s v), for digital images. The code for continuous and discrete computational frameworks is freely available and is now the part of the more general CorrelationFunctions.jl package. • We developed a truly exact method of computing surface–surface functions in continuous manner. • Previous method to compute discrete surface functions was improved with a novel edge filter. • We verified discrete and continuous methods using analytical solutions. • The influence of image resolution on the digital computations was explored. • All developed approaches are presented open source with documentation. [ABSTRACT FROM AUTHOR]

An accurate estimation of the position, orientation, principal curvatures, and change in intensity of the edges in a 3D image provides highly useful information for many applications. The use of derivative operators to compute the gradient vector and the Hessian matrix in each voxel usually generates inaccurate results. This paper presents a new edge detector which is derived from the Partial Volume Effect (PVE). Instead of assuming continuity in the image values, edge features are extracted from the distribution of intensities within a neighborhood of each edge voxel. First, the influence of the intensities of the voxels in first- and second-order edges is analyzed to demonstrate that these types of edges can be precisely characterized from the intensity distribution. Afterward, this approach is extended to especially demanding situations by considering how adverse conditions can be tackled. This extension includes filtering noisy images, characterizing edges in blurred regions, and using windows with floating limits for close edges. The proposed technique has been tested on synthetic and real images, including some particularly difficult objects, and achieving a highly accurate subvoxel characterization of the edges. An open source implementation of our method is provided. • Extraction of edge features assuming the partial volume effect. • High accuracy in subvoxel position and change in intensity. • Estimation of orientation and principal curvatures. • Recovery of edge features in blurred edges and noisy images. • Use of windows with floating limits in close edges. [ABSTRACT FROM AUTHOR]

Holoprinters based on holographic stereograms (HS) have been developed to synthesize holograms by using 2D images with perspective information of 3D objects. The objects can be real or computer generated. HS has been applied to different fields such as engineering, medicine and military because the high visual impact of the tridimensional and multi-view images it presents. To implement a Holoprinter requires development of three components: i) 2D images generation, ii) optical system design for HS recording and iii) mechanical and control implementation. Therefore, we design and develop each of the components, which integrated compose a holoprinter to synthesize full parallax HS. This paper studies basis for production of this kind ofholograms and describes the computational and opto-mechanical design and implementation that we have made. Experimental HS were obtained to validate the system. [ABSTRACT FROM AUTHOR]

Tracking the 3D image feature points of aerobic movements of high difficulty can improve the quality of aerobic movements. The current method takes the windowed area as the tracking template to complete the track of feature points with low efficiency. For that reason, a method based on Gabor is presented with which to track the 3D image feature points of aerobic movements of high difficulty. The method extracts feature points with SIFT algorithms, classifies feature points according to AdaBoost algorithms, and tracks feature points through the image pyramid. The experiment shows that the mentioned method enhances the accuracy of tracking the 3D image feature points of aerobic movements. [ABSTRACT FROM AUTHOR]

This paper focuses on challenging applications that can be expressed as an iterative pipeline of multiple 3d stencil stages and explores their optimization space on GPUs. For this study, we selected a representative example from the field of digital signal processing, the Anisotropic Nonlinear Diffusion algorithm. An open issue to these applications is to determine the optimal fission/fusion level of the involved stages and whether that combination benefits from data tiling. This implies exploring a large space of all the possible fission/fusion combinations with and without tiling, thus making the process non-trivial. This study provides insights to reduce the optimization tuning space and programming effort of iterative multiple 3d stencils. Our results demonstrate that all combinations that fuse the bottleneck stencil with high halos update cost (>25%, this percentage can be measured or estimated experimentally for each single stencil) and high registers and shared memory accesses must not be considered in the exploration process. The optimal fission/fusion combination is up to 1.65× faster than the case in which we fully decompose our stencil without tiling and 5.3× faster with respect to the fully fused version on the NVIDIA GPUs. [ABSTRACT FROM AUTHOR]

Many successful models of saliency have been proposed to detect salient regions for 2D images. Because stereopsis, with its distinctive depth information, influences human viewing, it is necessary for stereoscopic saliency detection to consider depth information as an additional cue. In this paper, we propose a 3D stereoscopic saliency model based on both contrast and depth-guided-background prior. First, a depth-guided-background prior is specifically detected from a disparity map apart from the conventional prior, assuming boundary super-pixels as background. Then, saliency based on disparity with the help of the proposed prior is proposed to prioritize the contrasts among super-pixels. In addition, a scheme to combine the contrast of disparity and the contrast of color is presented. Finally, 2D spatial dissimilarity features are further employed to refine the saliency map. Experimental results on the PSU stereo saliency benchmark dataset (SSB) show that the proposed method performs better than existing saliency models. [ABSTRACT FROM AUTHOR]

Backgrounds: Some patients have P6a running on the ventral side (Ventral-P6a), relative to the right hepatic vein (RHV).Study Design: Forty-one patients who underwent left trisectionectomy or central bisectionectomy for biliary cancer were enrolled. We compared the anatomical features using 3D images and surgical outcomes between patients with Ventral-P6a (n = 17) and those with P6a running on the dorsal side relative to the RHV (Dorsal-P6a; n = 25). Moreover, the liver volume by hand-tracing 2D axial images was compared to the volume calculated using the 3D images.Results: The frequency of complete exposure of RHV on the transection plane was less in Ventral-P6a (12 vs. 76%; p < 0.001), and the frequency of supraportal type of right posterior hepatic artery (RPHA, 29 vs. 4%, p = 0.020), the presence of inferior RHV (47 vs. 12%, p = 0.011), and the angle between the transection plane of segment VI and VII (S6-S7angle, 29.0° vs. 4.9°; p < 0.001) were greater in Ventral-P6a than in Dorsal-P6a. In Dorsal-P6a, the volume of posterior section calculated using 2D images was greater than that calculated using 3D images (404 vs. 370 mL; p = 0.004). The incidence of daily diuretic administration in Dorsal-P6a was greater than in Ventral-P6a (88 vs. 54%, p = 0.035).Conclusion and Relevance: In Ventral-P6a, the complete exposure of RHV was rare in left trisectionectomy or central bisectionectomy. Surgeons should preoperatively recognize the course of RPHA, the presence of inferior RHV, and the S6-S7angle. In Dorsal-P6a, the volume of posterior section, which tended to be overestimated using 2D images, was smaller than that in Ventral-P6a. [ABSTRACT FROM AUTHOR]

The granulometry operator is a mathematical operator largely employed in the 3D analysis of porous media to estimate the sizes of the pores detected in pervious materials and tissues. Quantifying the total porosity volume in a material with only closed pores is a relatively easy task. A simple numerical analysis of connected void or fluid phase components enables one to obtain such a volume. Unfortunately, for materials and/or tissues with (partly) open porosity granulometry calculations might become excessively time and memory consuming. In this work we suggest a method by means of which the open porosity map can be rapidly calculated on the basis of a pre-calculated distance map. [ABSTRACT FROM AUTHOR]

To produce realistic synthetic images, it is important to shade objects based on real illumination conditions of a scene. Estimating the direction of the light source of the scene is a key factor to achieve this. Properly estimating this source under noisy conditions is very challenging, and it is a subject of intense research. Computational intelligence techniques offer promising way of tackling this problem. This paper presents a novel neural network-based approach for recovering light source direction in relation to the viewpoint direction of a graphical image in noisy environments. The estimated light source direction can be used for the generation of 3D images from 2D ones. Experiments are performed using both synthetic and real images in noisy scenes. Four synthetic surfaces where generated with varying light source directions for a total of 12 images. Three real images were also used with varying degrees of noise. The experimental results show that the proposed approach is robust and provides a good level of accuracy. [ABSTRACT FROM AUTHOR]

This paper presents analysis on two 3D mesh to 2D map strategies applied to unwrap images of rock tunnels and facilitate visualization of large datasets. First, we examined mesh parameterization algorithms which are used in computer graphics to convert a 3D mesh model to a 2D representation. We found that while these methods were automatic and could provide 2D maps with minimal metric distortion (ie: conservation of lengths in 3D when mapped to 2D), they exhibited twisted shapes and were not intuitive to interpret. Second, we proposed two novel approaches, combining mesh deformation algorithms, which are used in computer animation to reshape a 3D mesh to resemble a 3D plane, and projection onto a 2D plane. We found that while these methods required user interaction and introduced a greater amount of metric distortion, their outputs were fairly intuitive to interpret. To compare the relative merits of mesh parameterization and mesh deformation and projection, the different strategies are applied to a 8.2 m wide by 41 m long by 6.7 m high subsection of a mining tunnel. The metric distortion produced was calculated and their respective output 2D maps are presented and discussed. [ABSTRACT FROM AUTHOR]

Recent studies have examined various aspects of human physical attractiveness. Attractiveness is considered an evolved psychological mechanism acquired via natural selection because an attractive body reflects an individual's health and fertility. The length of the legs is an often-emphasized aspect of attractiveness and has been investigated using the leg-to-body ratio (LBR), which reflects nutritional status of the infant, health status, fecundity, and other factors that are predictive of physical fitness. However, previous studies of leg length and physical fitness have produced mixed results. The present study investigated the relationship between LBR, defined as the height to perineum divided by total height, and perceived attractiveness. Three-dimensional stimuli (11 male and 11 female) were constructed with various LBR features. Each stimulus was rated by 40 women and 40 men in Japan on a 7-point scale. The results showed that the values closest to the average LBRs were rated as the most attractive. Furthermore, by fitting a quadratic curve on the relationship between attractiveness and LBR, an inverted U-shaped curve with the peak located at the average LBR was observed. In addition, high LBR values were rated as more attractive in females, whereas the opposite was true for males. These results suggest that average LBR is indicative of good health and good reproductive potential, whereas more extreme values are avoided because they could be indicative of diseases and other maladaptive conditions. [ABSTRACT FROM AUTHOR]

Teeth develop within the surrounding periodontal tissues, involving the alveolar bone, periodontal ligament and cementum. The alveolar bone originates through the process of intramembranous ossification involving mesenchymal cells from the tooth germ. As most available data are related to endochondral ossification, we examined the molecular background of alveolar bone development. We investigated the osteogenic profile of mesenchymal cells dissected from mouse mandible slices at the stage of early alveolar bone formation. Relative monitoring of gene expression was undertaken using PCR Arrays; this included the profiles of 84 genes associated with osteogenesis. To examine the tooth-bone interface, stages with detectable changes in bone remodelling during development (E13.0, E14.0 and E15.0) were chosen and compared with each other. These results showed a statistically significant increase in the expression of the genes Fgf3, Ctsk, Icam-1, Mmp9, Itga3 and Tuft1, and of a wide range of collagens (Col1a2, Col3a1, Col7a1, Col12a1, Col14a1). Decreased expression was detected in the case of Col2a1, Sox9, Smad2 and Vegfb. To confirm these changes in gene expression, immunofluorescence analyses of Mmp9 and Sox9 proteins were performed in situ. Our research has identified several candidate genes that may be crucial for the initiation of alveolar bone formation and is the basis for further functional studies. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

In this manuscript we suggest a three-dimensional reconstruction technique to fully characterize structural performance of solid materials. The described technique extrapolates, measures and interprets the 3-dimensional data which is extracted from SEM images, obtained from different angles. Further, finer results were achieved by extrapolating of spatial data from three or more sample images using visual reconstruction software applications. Gold particles, silicon wafers and dendrites were selected as model materials for the spatial 3D surface reconstruction. For comparison and proof-of-concept, stereoscopy technique was also included into the research. [ABSTRACT FROM AUTHOR]

With the proliferation of 3D image data comes the need for advances in automated spatial reasoning. One specific challenge is the need for a practical mapping between spatial reasoning and human cognition, where human cognition is expressed through natural-language terminology. With respect to human understanding, researchers have found that errors about spatial relations typically tend to be metric rather than topological; that is, errors tend to be made with respect to quantitative differences in spatial features. However, topology alone has been found to be insufficient for conveying spatial knowledge in natural-language communication. Based on previous work that has been done to define metrics for two lines and a line and a 2D region in order to facilitate a mapping to natural-language terminology, herein we define metrics appropriate for 3D regions. These metrics extend the notions of previously defined terms such as splitting, closeness, and approximate alongness. The association between this collection of metrics, 3D connectivity relations, and several English-language spatial terms was tested in a human subject study. As spatial queries tend to be in natural language, this study provides preliminary insight into how 3D topological relations and metrics correlate in distinguishing natural-language terms. [ABSTRACT FROM AUTHOR]

To perform three-dimensional measurements (volume and area) of the maxillary sinus, from cone-beam computed tomography (CBCT) images, and to assess potential differences between the left and right sides and a correlation of the measurements to sex, age, skin color, and nutritional status. CBCT images of 161 living Brazilian subjects of both sexes (89 women and 72 men) were used, and three-dimensional measurements of volume and area were made with the beta version of the DDS-Pro™ 2.14.2_2022 software (DPP Systems, Czestochowa, Poland). The inter- and intra-examiner reproducibility of measurements was evaluated with TEM, rTEM, and R. Both maxillary sinus volume and area did not show significant differences between the left and right sides and between the sexes. Volume and area were significantly lower in the age group from 6 to 11 years than in the other two groups (p < 0.05). The measurements obtained for maxillary sinus volume and area were significantly higher in white individuals (p < 0.05), but they did not show significant differences (p > 0.05) regarding nutritional status (considering the body mass index - BMI). There were no statistically significant differences between the sexes, which does not allow recommending the use of maxillary sinus volume and area measurements to analyze sexual dimorphism, and the same occurs for BMI. However, such measures can help to estimate the age and skin color of individuals. • There was no sexual dimorphism in 3D maxillary sinuses (MS) measurements. • Different age groups presented different MS volumetric data. • There were differences in MS area and volume between black and white subjects. • Normal and above normal BMI people didn't present differences in 3D MS measurements. • MS 3D measurements may be used to estimate age and skin color. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine and assess comparative values of HRCT-based multiplanar reformation (MPR), volume rendering (VR) and virtual endoscope built on three-dimensional (3D) shaded-surface display (SSD-based CTVE) for detections of ossicular chain's damage in patients with otitis media. 70 human ears from 70 patients suffering by chronic otitis media or cholesteatoma, who were examined with a preoperative multi-slice computer tomography (MSCT) examination and tympanoplasty in our hospital were collected. The patients ossicular chains were reconstructed with the aforementioned three protocols and assessed via a three-point scoring system by three radiologists. Then, all the patients ossicular chains were reviewed by a surgeon and a radiologist via the same three-point scoring system used during surgeries at same time. By calculation, the Youden's index and coincidence rate were acquired without a significant difference for display of malleus. With regard to the incus, the Youden's index and coincidence rate of VR and MPR did not show any difference, however, both were higher than CTVE. For representation of the stapes, the accuracy of these three modalities is very low; especially, for the CTVE. In conclusion, both MPR and VR are relative robust, and CTVE is not effective for evaluation of small ossicular structures, particularly the stapes. Furthermore, the VR images are real 3D ones. Therefore, it could be the more valuable protocols for detection of the damage of ossicular chain in the patients with otitis media, and should be further applied in the future work. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents an approach to achieve morphological characterizing for complex porous materials based on micro X-ray tomography images, with an example of a novel porous metal fiber sheet produced through solid-state sintering method. The geometrical reconstruction was performed after selection of volume of interest and image processing of anisotropic diffusion smooth. The reconstructed gray level images were then transferred into binary images by adjusting binarization threshold according to the actual porosity. Taking into account the tubular structural feature of the fibers, skeleton extraction algorithm based on the distance transform function was applied and further improved by the scale axis transform method. The skeleton was later pruned and segmented according to the contact points to perform morphological characterizing. Compared with actual manufacturing parameters, the style, length, radius, orientation and tortuosity of fiber segments were discussed. The results show that our proposed method can well describe the actual geometrical and morphological characteristics, which will provide a promising method for the structural description of fibrous networks. [Copyright &y& Elsevier]

We suggest a symmetric-polar pixellation scheme which makes possible a reduction of the computational cost for expectation maximization (EM) iterative algorithms. The proposed symmetric-polar pixellation allows us to deal with 3D images as a whole problem without dividing the 3D problem into 2D slices approach. Performance evaluation of each approach in terms of stability and image quality is presented. Exhaustive comparisons between all approaches were conducted in a 2D based image reconstruction model. From these 2D approaches, that showing the best performances were finally implemented and evaluated in a 3D based image reconstruction model. Comparison to 3D images reconstructed with FBP is also presented. Although the algorithm is presented in the context of computed tomography (CT) image reconstruction, it can be applied to any other tomographic technique as well, due to the fact that the only requirement is a scanning geometry involving measurements of an object under different projection angles. Real data have been acquired with a small animal (CT) scanner to verify the proposed mathematical description of the CT system. [ABSTRACT FROM AUTHOR]

This paper presents a new framework for an interactive segmentation of 3D images. The framework is based on a bimodal data structure defined by a region adjacency graph (RAG) that is associated with a hierarchical classification tree (HCT). The RAG provides information about the spatial and topological organisation of the extracted regions of the image. The HCT provides information about the similarities between the extracted regions of the image based on a predefined set of features. The first contribution of our work is the combination of a RAG and a HCT. An incremental system was obtained by defining operators that work with and on the RAG and the HCT. If a static predefined processing chain has been defined, these operators can be used in batch mode. If a scheduler is available, they can be used in an adaptive manner. Finally, if a user chooses the operator to be used after each step, the operators can be used interactively. The second contribution of this paper is the formal description of these operators. To give the user the ability to incrementally improve the segmentation, powerful visualisation of the segmentation state and interfaces have been proposed, an important advantage of the proposed framework. To validate the proposed framework, a user study has been conducted in a concrete case of texture segmentation. Our system obtains very satisfactory results even for complex volumetric textures, and helps real users by providing high quality segmentations. The system has been tested by specialists in sonography to segment 3D ultrasound images of the skin. Some examples of segmentation are presented to illustrate the benefit of the interactivity provided by our approach. [ABSTRACT FROM AUTHOR]

Abstract: The features associated with modern synchrotron radiation machines (intense and coherent beams) result in a substantial extension of X-ray imaging capabilities in terms of spatial and temporal resolution, phase contrast and 3D images. This allows crystal growth-related information to be obtained which is not available otherwise. After briefly describing the main synchrotron radiation based imaging techniques of interest, we give original examples illustrating the new capabilities for crystal growth: characterisation of crystals grown for applications, such as ice tri-crystals produced for mechanical deformation studies; SiC; crystalline silicon for solar photovoltaic cells; in situ and in real time studies of quasicrystal growth (AlPdMn); and ultrafast tomography for the study of the growth of dendrites in metallic alloys. [Copyright &y& Elsevier]

With the progress of network transmission technology, the popularity of smart phones, the rise of social networking sites and micro-film, the birth of the fourth screen and the boom of 3D images and network industry, the media market has been shaped dramatically. As video sharing website is becoming more and more popular, it provides a great opportunity for creative young people to showcase their creativity and videos through these networks. This article is written for the young people who are interested in joining the imaging industry, summarizing the rapid development and transformation of the media industry. Hopefully it can provide some insights of the industry and inspire creative direction for young people. [ABSTRACT FROM AUTHOR]

The morphological tortuosity of a geodesic path in a medium can be defined as the ratio between its geodesic length and the Euclidean distance between its two extremities. Thus, the minimum tortuosity of all the geodesic paths into a medium in 2D or in 3D can be estimated by image processing methods using mathematical morphology. Considering a medium, the morphological tortuosities of its internal paths are estimated according to one direction, which is perpendicular to both starting and ending opposite extremities of the geodesic paths. The used algorithm estimates the morphological tortuosities from geodesic distance maps, which are obtained from geodesic propagations. The shape of the propagated structuring element used to estimate the geodesic distance maps on a discrete grid has a direct influence on the morphological tortuosity and has to be chosen very carefully. The results of our algorithm is an image with pixels p having a value equal to the length of the shortest path containing p and connected to two considered opposite boundaries A and B of the image. The analysis of the histogram of the morphological tortuosities gives access to their statistical distribution. Moreover, for each tortuosity the paths can be extracted from the original image, which highlights the location of them into the sample. However, these geodesic paths have to be reconstructed for further processing. The extraction, because applying a threshold on the tortuosities, results in disconnected components, especially for highly tortuous paths. This reconstruction consists in reconnecting these components to the geodesic path linking the two opposite faces, by means of a backtracking algorithm. [ABSTRACT FROM AUTHOR]

Fractures of the proximal humerus are typical osteoporotic fractures of the elderly with an increasing incidence. Computed tomography (CT) with 3D reconstruction plays a more and more decisive role in the diagnostics because of an improved understanding of fractures in 3D images. The resulting correct fracture classification has significance for the decision of the best therapy procedure. Currently an extended version of the Codman classification with its four and more fragments is used to give additive information about varus or valgus dislocation, impression or distraction. The comparison of conservative and operative treatment showed no predominance of one of the procedures, therefore both strategies are justified. An operative treatment is recommended in complex fractures. Thus, early functional mobilization, early self-dependence and return to the activities of daily living are possible. Intramedullary nailing is advised in 2-part fractures, in dislocated multipart fractures locking plating or a primary reverse shoulder arthroplasty with refixation of the tuberosities in patients over 75 years. However, the improved plate and nail systems with polyaxiality, calcar screws, modern plate and nails designs as well as the possibility of arthroscopy-assisted nail implantation or plate removal combined with arthroscopic arthrolysis are innovative. [ABSTRACT FROM AUTHOR]

Background: Further advances in modern microscopy are leading to teravoxel-sized tiled 3D images at high resolution, thus increasing the dimension of the stitching problem of at least two orders of magnitude. The existing software solutions do not seem adequate to address the additional requirements arising from these datasets, such as the minimization of memory usage and the need to process just a small portion of data. Results: We propose a free and fully automated 3D Stitching tool designed to match the special requirements coming out of teravoxel-sized tiled microscopy images that is able to stitch them in a reasonable time even on workstations with limited resources. The tool was tested on teravoxel-sized whole mouse brain images with micrometer resolution and it was also compared with the state-of-the-art stitching tools on megavoxel-sized publicy available datasets. This comparison confirmed that the solutions we adopted are suited for stitching very large images and also perform well on datasets with different characteristics. Indeed, some of the algorithms embedded in other stitching tools could be easily integrated in our framework if they turned out to be more effective on other classes of images. To this purpose, we designed a software architecture which separates the strategies that use efficiently memory resources from the algorithms which may depend on the characteristics of the acquired images. Conclusions: TeraStitcher is a free tool that enables the stitching of Teravoxel-sized tiled microscopy images even on workstations with relatively limited resources of memory (< 8 GB) and processing power. It exploits the knowledge of approximate tile positions and uses ad-hoc strategies and algorithms designed for such very large datasets. The produced images can be saved into a multiresolution representation to be efficiently retrieved and processed. We provide TeraStitcher both as standalone application and as plugin of the free software Vaa3D. [ABSTRACT FROM AUTHOR]

Abstract: Automated segmentation and analysis of tree-like structures from 3D medical images are important for many medical applications, such as those dealing with blood vasculature or lung airways. However, there is an absence of large databases of expert segmentations and analyses of such 3D medical images, which impedes the validation and training of proposed image analysis algorithms. In this work, we simulate volumetric images of vascular trees and generate the corresponding ground-truth segmentations, bifurcation locations, branch properties, and tree hierarchy. The tree generation is performed by iteratively growing a vascular structure based on a user-defined (possibly spatially varying) oxygen demand map. We describe the details of the algorithm and provide a variety of example results. [ABSTRACT FROM AUTHOR]

Abstract: The European Modular Cultivation System (EMCS) on the ISS allows long-term biological experiments, e.g. on plants. Video cameras provide near real-time 2D images from these experiments. A method to obtain 3D coordinates and stereoscopic images from these 2D images has been developed and is described in this paper. The procedure was developed to enhance the data output of the MULTIGEN-1 experiment in 2007. One of the main objectives of the experiment was to study growth movements of the Arabidopsis plants and the effect of gravity on these. 3D data were important during parts of the experiment and the paper presents the method developed to acquire 3D data, the accuracy of the data, limitations to the technique and ways to improve the accuracy. Sequences of 3D data obtained from the MULTIGEN-1 experiment are used to illustrate the potential of this newfound capability of the EMCS. In the experiment setup, a positional depth accuracy of about ±0.4mm for relative object distances and an absolute depth accuracy of about ±1.4mm for time dependent phenomena was reached. The ability to both view biological specimens in 3D as well as obtaining quantitative 3D data added greatly to the scientific output of the MULTIGEN-1 experiment. The uses of the technique to other researchers and their experiments are discussed. [Copyright &y& Elsevier]

Quantitative evaluation of axial vertebral rotation is essential for the determination of reference values in normal and pathological conditions and for understanding the mechanisms of the progression of spinal deformities. However, routine quantitative evaluation of axial vertebral rotation is difficult and error-prone due to the limitations of the observer, characteristics of the observed vertebral anatomy and specific imaging properties. The scope of this paper is to review the existing methods for quantitative evaluation of axial vertebral rotation from medical images along with all relevant publications, which may provide a valuable resource for studying the existing methods or developing new methods and evaluation strategies. The reviewed methods are divided into the methods for evaluation of axial vertebral rotation in 2D images and the methods for evaluation of axial vertebral rotation in 3D images. Key evaluation issues and future considerations, supported by the results of the overview, are also discussed. [ABSTRACT FROM AUTHOR]

In the framework of the Silent Wall ANR project, the CMM and the US2B are associated in order to characterize and to model fibrous media studying 3D images acquired with an X-Ray tomograph used by the US2B. The device can make 3D images of maximal 23043 voxels with resolutions in the range of 2 μm to 15 μm. Using mathematical morphology, measurements on file 3D X-Ray CT images are used to characterize materials. For example measuring the covariance on these images of an acoustic insulating material made of wooden fibres highlights the isotropy of the fibres orientations in the longitudinal planes which are perpendicular to the compression Oz axis. Moreover, it is possible to extract other morphological properties from these image processing methods such as the size distribution either of the fibres or of the pores by estimating the morphological opening granulometry of the considered medium. Using the theory of random sets introduced by Georges Matheron in the early 1970's, the aim of this work is to model such a fibrous material by parametric random media in 3D according to the prior knowledge of its morphological properties (covariance, porosity, size distributions, etc.). A Boolean model of random cylinders in 3D stacked in planes parallel to each other and perpendicular to the Oz compression axis is first considered. The granulometry results provide gamma distributions for the radii of the fibres. In addition, a uniform distribution of the orientations is chosen, according to the experimental isotropy measurements in the longitudinal planes. Finally the third statistical factor is the length distribution of the fibres which can be fitted by an exponential distribution. Thus it is possible to estimate the validity of this model first by trying to fit the experimental transverse and longitudinal covariances of the pores with the theoretical ones taking into account the statistical distributions of the dimensions of the random cylinders. The second method to validate the model consists in comparing morphological measurements (density profiles, covariance, opening granulometry, tortuosity, specific surface area) processed on real and on simulated media. [ABSTRACT FROM AUTHOR]

The aim of this paper is to provide a complete overview of the existing methods for quantitative evaluation of spinal curvature from medical images, and to summarize the relevant publications, which may not only assist in the introduction of other researchers to the field, but also be a valuable resource for studying the existing methods or developing new methods and evaluation strategies. Key evaluation issues and future considerations, supported by the results of the overview, are also discussed. [ABSTRACT FROM AUTHOR]

Little is known about how amyloid-β (Aβ) is deposited in relation to the complex ultrastructure of the brain. Here we combined serial section immunoelectron microscopy with 3D reconstruction to elucidate the spatial relationship between Aβ deposits and ultrastructurally identified cellular compartments. The analysis was performed in a transgenic mouse model with mutant presenilin-1, and mutant amyloid-β protein precursor (AβPP) and tau transgenes (3xTg-AD mice) and in aged dogs that develop Aβ plaques spontaneously. Reconstructions based on serial ultrathin sections of hippocampus (mice) or neocortex (dogs) that had been immunolabeled with Aβ (Aβ_{1-42}) antibodies showed that the organization of extracellular Aβ deposits is more complex than anticipated from light microscopic analyses. In both species, deposits were tightly associated with plasma membranes of pyramidal cell bodies and major dendrites. The deposits typically consisted of thin sheets as well as slender tendrils that climbed along the large caliber dendritic stems of pyramidal neurons. No preferential association was observed between Aβ deposits and thin dendritic branches or spines, nor was there any evidence of preferential accumulation of Aβ around synaptic contacts or glial processes. Our data suggest that plaque formation is a precisely orchestrated process that involves specialized domains of dendrosomatic plasma membranes. [ABSTRACT FROM AUTHOR]

• A mixture rule can predict the green density of Ti6Al4V/xAg powder mixes. • Pore filling by liquid phase drives the densification of Ti6Al4V/xAg composites. • Formation of Ti 2 Ag and TiAg is due to solid state diffusion into the Ti6Al4V matrix. • Isolated pores are obtained by adding 20 vol% of Ag into Ti6Al4V matrix. • Microhardness shows a linearly behavior with respect to the relative density. This work investigates the fabrication of Ti6Al4V/xAg composites processed by powder metallurgy. An atomized Ti6Al4V powder was blended with 0, 5, 10, 15 and 20 vol% of Ag particles, compacted in a die, and sintered above Ag melting point. The compressibility of the mixtures was analyzed, and the sintering kinetics was evaluated by dilatometry tests. The characterization of sintered samples by microtomography, SEM and diffraction analysis allowed determining the effect of Ag amount on the sintering process and on microstructural changes arising during sintering. The mechanical properties of sintered materials were investigated by microhardness. The compressibility of Ti6Al4V powder was found to be improved by adding soft Ag particles, which resulted in denser packing and larger plastic deformation. The densification during compaction can be predicted by Heckel model and the rule of mixture. It was next found that sintering was driven by volume diffusion in the solid state for Ag content lower than 10 vol% and involved a liquid phase for Ag content higher than 15 vol%. In the latter case, the liquid fills the interconnected pores under the action of capillary forces as the quantity of liquid increased. The microstructure was composed mainly of α-Ti, Ti 2 Ag, and Ag, which filled the pores between Ti6Al4V particles. Microhardness data showed a maximum value with 20 vol% of Ag. This value is similar to those reported for highly dense Ti6Al4V. It has thus proved that close to full-dense Ti6Al4V/20Ag composites can be processed by powder metallurgy. [ABSTRACT FROM AUTHOR]

During a Disaster Victims Identification (DVI) mission, international protocols rely on interdisciplinary work, especially between specialists from forensic imaging and anthropology. In case of air crashes or explosions, DVI units may face thousands of fragmented human remains (FHRs). The physical re-association of FHRs and the identification process is very complex and challenging, and relies upon expensive and destructive DNA analysis. A virtual re-association (VRA) of these fragments, using Multidetector Computed Tomography (MDCT), could be a helpful tool in forensic anthropology analysis, as it could assist in reducing the number of DNA samples. However, there is no standardized protocol for including such an approach into a DVI procedure. The aim of this study was to summarize and analyze existing techniques through a systematic review and to develop a protocol for virtual re-association of FHRs, adapted to the DVI context. A keyword-based literature search was conducted, focusing on the VRA methods using MDCT imaging and 3D surface scan methodology. Reviews and primary articles, published between 2005 and 2020 in the fields of forensic anthropology, paleoanthropology, archeology, and fracture reduction surgery were sorted out. A total of 45 publications were selected and analyzed based on their content and relevance. The results show that research on the re-association of FHRs increased significantly during the last five years. Seven steps regarding the MDCT-based method for the virtual re-association of FHRs could be identified: acquisition of 3D-images, segmentation of the MDCT-data, post-processing and surface generation, identification of intact and fracture surfaces, identification and registration of matching fragments, and validation of the re-association. The literature is surprisingly sparse regarding the FHRs re-association as a forensic tool, and mainly consists in case reports, whereas validated methods were presented in archeology and surgery publications. However, we were able to adapt the MDCT-based approach for the virtual re-association of the FHRs and propose an innovative protocol for DVI missions. This protocol includes the needed details, from the acquisition of MDCT imaging to the virtual re-association of 3D models and its validation. Each step has to be fully tested, adapted and validated in future studies. [ABSTRACT FROM AUTHOR]