Liver shape analysis using statistical parametric maps at population scale.

BACKGROUND: Morphometric image analysis enables the quantification of differences in the shape and size of organs between individuals. METHODS: Here we have applied morphometric methods to the study of the liver by constructing surface meshes from liver segmentations from abdominal MRI images in 33,434 participants in the UK Biobank. Based on these three dimensional mesh vertices, we evaluated local shape variations and modelled their association with anthropometric, phenotypic and clinical conditions, including liver disease and type-2 diabetes. RESULTS: We found that age, body mass index, hepatic fat and iron content, as well as, health traits were significantly associated with regional liver shape and size. Interaction models in groups with specific clinical conditions showed that the presence of type-2 diabetes accelerates age-related changes in the liver, while presence of liver fat further increased shape variations in both type-2 diabetes and liver disease. CONCLUSIONS: The results suggest that this novel approach may greatly benefit studies aiming at better categorisation of pathologies associated with acute and chronic clinical conditions.

Nonfluoroscopic 3D Image Guidance System Reduces Navigation Times Through Five 3D-Printed Iliofemoral Vascular Phantoms.

PURPOSE: To assess the potential adjunctive role of a 3D electromagnetic (EM) navigational system for use in above-knee vessels afflicted with peripheral artery disease (PAD). Peripheral artery disease can be challenging to operators encountering significant vessel tortuosity, calcium, and stenoses, which may require prolonged procedure times and excessive use of nephrotoxic iodinated contrast when performed with conventional fluoroscopy. MATERIALS AND METHODS: Following appropriate ethical oversight, five 3D-printed bench phantoms modeling tortuous calcified PAD were created based on source CTA (computed tomography angiography) data sets from real patients. Investigational software was developed based on a commercially available aortic EM navigation platform (Intraoperative Positioning System [IOPS]; Centerline Biomedical, Inc., Cleveland, Ohio), with patient-specific structural maps of vessel lumens and calcification. Using a sensorized prototype 6 French (Fr) catheter and 0.035" guidewire, 15 interventionalists traversed each phantom using the EM platform as well as 2D simulated fluoroscopy-like image guidance and the times were recorded. Participants completed a 10-item standard system usability scale (SUS) questionnaire (score 1-5, 5=strongly agree) evaluating system usability and user satisfaction. Navigation times and SUS scores were compared with a 1-tailed statistical t test. RESULTS: Participants demonstrated a statistically significant reduction in navigation times using EM guidance, performing 0.7 minutes (42 seconds) faster on average (P < .001), corresponding to a 25% average relative reduction. Participants reported sufficiently high levels of usability satisfaction, with a mean SUS score of 4.29 (P < .001), exceeding the acceptance criterion (score ≥3.5). CONCLUSION: This preclinical phantom study highlights the future potential of Centerline Biomedical's EM navigation technology as a possible adjunct to fluoroscopy for highly precise visualization and navigation of PAD-afflicted vasculature. CLINICAL IMPACT: This preclinical proof-of-concept study highlights the feasibility of EM navigation not only for branch vessel cannulation, but also for inline navigation of peripheral vessels afflicted with calcified plaques via benchtop iliofemoral phantom simulations. The navigation platform studied addresses the need for improvements in EM technology through modelling algorithms that facilitate 3D visualization of calcified plaque in any projection in real time, in addition to sensorization of both catheter and guidewire in a compact 6Fr system.

Kidney shape statistical analysis: associations with disease and anthropometric factors.

BACKGROUND: Organ measurements derived from magnetic resonance imaging (MRI) have the potential to enhance our understanding of the precise phenotypic variations underlying many clinical conditions. METHODS: We applied morphometric methods to study the kidneys by constructing surface meshes from kidney segmentations from abdominal MRI data in 38,868 participants in the UK Biobank. Using mesh-based analysis techniques based on statistical parametric maps (SPMs), we were able to detect variations in specific regions of the kidney and associate those with anthropometric traits as well as disease states including chronic kidney disease (CKD), type-2 diabetes (T2D), and hypertension. Statistical shape analysis (SSA) based on principal component analysis was also used within the disease population and the principal component scores were used to assess the risk of disease events. RESULTS: We show that CKD, T2D and hypertension were associated with kidney shape. Age was associated with kidney shape consistently across disease groups. Body mass index (BMI) and waist-to-hip ratio (WHR) were also associated with kidney shape for the participants with T2D. Using SSA, we were able to capture kidney shape variations, relative to size, angle, straightness, width, length, and thickness of the kidneys, within disease populations. We identified significant associations between both left and right kidney length and width and incidence of CKD (hazard ratio (HR): 0.74, 95% CI: 0.61-0.90, p < 0.05, in the left kidney; HR: 0.76, 95% CI: 0.63-0.92, p < 0.05, in the right kidney) and hypertension (HR: 1.16, 95% CI: 1.03-1.29, p < 0.05, in the left kidney; HR: 0.87, 95% CI: 0.79-0.96, p < 0.05, in the right kidney). CONCLUSIONS: The results suggest that shape-based analysis of the kidneys can augment studies aiming at the better categorisation of pathologies associated with chronic kidney conditions.

MRI visible Fe3O4 polypropylene mesh: 3D reconstruction of spatial relation to bony pelvis and neurovascular structures.

INTRODUCTION AND HYPOTHESIS: To demonstrate mesh magnetic resonance imaging (MRI) visibility in living women, the feasibility of reconstructing the full mesh course in 3D, and to document its spatial relationship to pelvic anatomical structures. METHODS: This is a proof of concept study of three patients from a prospective multi-center trial evaluating women with anterior vaginal mesh repair using a MRI-visible Fe3O4 polypropylene implant for pelvic floor reconstruction. High-resolution sagittal T2-weighted (T2w) sequences, transverse T1-weighted (T1w) FLASH 2D, and transverse T1w FLASH 3D sequences were performed to evaluate Fe3O4 polypropylene mesh MRI visibility and overall post-surgical pelvic anatomy 3 months after reconstructive surgery. Full mesh course in addition to important pelvic structures were reconstructed using the 3D Slicer® software program based on T1w and T2w MRI. RESULTS: Three women with POP-Q grade III cystoceles were successfully treated with a partially absorbable MRI-visible anterior vaginal mesh with six fixation arms and showed no recurrent cystocele at the 3-month follow-up examination. The course of mesh in the pelvis was visible on MRI in all three women. The mesh body and arms could be reconstructed allowing visualization of the full course of the mesh in relationship to important pelvic structures such as the obturator or pudendal vessel nerve bundles in 3D. CONCLUSIONS: The use of MRI-visible Fe3O4 polypropylene meshes in combination with post-surgical 3D reconstruction of the mesh and adjacent structures is feasible suggesting that it might be a useful tool for evaluating mesh complications more precisely and a valuable interactive feedback tool for surgeons and mesh design engineers.

How else can we study sex differences in early infancy?

This paper revisits group difference and individual variability in birth weight, head size, Apgar score, and motor performance in neonatal and 8-month-old males and females using a large existing data set. The goal is primarily theoretical--to reframe existing analyses with an eye toward designing and executing more predictive analyses in the future. 3D graphing to visualize both the areas of overlap and regions of disparity between boys and girls has been used. A two-step cluster analysis of boys and girls together revealed three clusters. One was almost equally divided between boys and girls, but a second was highly enriched for boys and the third highly skewed toward girls. The relationship between cluster membership and Bayley motor scores at 8 months tested the hypothesis that initial differences that have no sex-related behavioral content might start processes that produce later sex-related differences. Initially, parental belief systems may be less important than infant care patterns evoked by basic size and health characteristics, even though later parental behaviors assume a decidedly gendered pattern.

A fine-grained orthodontics segmentation model for 3D intraoral scan data.

With the widespread application of digital orthodontics in the diagnosis and treatment of oral diseases, more and more researchers focus on the accurate segmentation of teeth from intraoral scan data. The accuracy of the segmentation results will directly affect the follow-up diagnosis of dentists. Although the current research on tooth segmentation has achieved promising results, the 3D intraoral scan datasets they use are almost all indirect scans of plaster models, and only contain limited samples of abnormal teeth, so it is difficult to apply them to clinical scenarios under orthodontic treatment. The current issue is the lack of a unified and standardized dataset for analyzing and validating the effectiveness of tooth segmentation. In this work, we focus on deformed teeth segmentation and provide a fine-grained tooth segmentation dataset (3D-IOSSeg). The dataset consists of 3D intraoral scan data from more than 200 patients, with each sample labeled with a fine-grained mesh unit. Meanwhile, 3D-IOSSeg meticulously classified every tooth in the upper and lower jaws. In addition, we propose a fast graph convolutional network for 3D tooth segmentation named Fast-TGCN. In the model, the relationship between adjacent mesh cells is directly established by the naive adjacency matrix to better extract the local geometric features of the tooth. Extensive experiments show that Fast-TGCN can quickly and accurately segment teeth from the mouth with complex structures and outperforms other methods in various evaluation metrics. Moreover, we present the results of multiple classical tooth segmentation methods on this dataset, providing a comprehensive analysis of the field. All code and data will be available at https://github.com/MIVRC/Fast-TGCN.

68 landmarks are efficient for 3D face alignment: what about more?: 3D face alignment method applied to face recognition.

This paper proposes a 3D face alignment of 2D face images in the wild with noisy landmarks. The objective is to recognize individuals from their single profile image. We first proceed by extracting more than 68 landmarks using a bag of features. This allows us to obtain a bag of visible and invisible facial keypoints. Then, we reconstruct a 3D face model and get a triangular mesh by meshing the obtained keypoints. For each face, the number of keypoints is not the same, which makes this step very challenging. Later, we process the 3D face using butterfly and BPA algorithms to make correlation and regularity between 3D face regions. Indeed, 2D-to-3D annotations give much higher quality to the 3D reconstructed face model without the need for any additional 3D Morphable models. Finally, we carry out alignment and pose correction steps to get frontal pose by fitting the rendered 3D reconstructed face to 2D face and performing pose normalization to achieve good rates in face recognition. The recognition step is based on deep learning and it is performed using DCNNs, which are very powerful and modern, for feature learning and face identification. To verify the proposed method, three popular benchmarks, YTF, LFW, and BIWI databases, are tested. Compared to the best recognition results reported on these benchmarks, our proposed method achieves comparable or even better recognition performances.

Inertial biometry from commercial 3D body meshes.

Body segments inertial parameters (or, more generally encompassing humans and animal species, inertial biometry), often necessary in kinetics calculations, have been obtained in the past from cadavers, medical 3D imaging, 3D scanning, or geometric approximations. This restricted the inertial archives to a few species. The methodology presented here uses commercial 3D meshes of human and animal bodies, which can be further re-shaped and 'posed', according to an underlying skeletal structure, before processing. The sequence of steps from virtually chopping the mesh to the estimation of inertial parameters of body segments is described. The accuracy of the method is tested by comparing the estimated results to real data published for humans (male and female), horses, and domestic cats. The proposed procedure opens the possibility of remarkably expanding biomechanics research when body size and shape change, or when external tools, such as prosthesis and sport material, take part in biological movement.

Primary Orbital Reconstruction with Selective Laser Melting (SLM) of Patient-Specific Implants (PSIs): An Overview of 96 Surgically Treated Patients.

Contemporary advances in technology have allowed the transfer of knowledge from industrial laser melting systems to surgery; such an approach could increase the degree of accuracy in orbital restoration. The aim of this study was to examine the accuracy of selective laser melted PSIs (patient-specific implants) and navigation in primary orbital reconstruction. Ninety-six patients with orbital fractures were included in this study. Planned vs. achieved orbital volumes (a) and angles (b) were compared to the unaffected side (n = 96). The analysis included the overlay of post-treatment on planned images (iPlan 3.0.5, Brainlab®, Feldkirchen, Germany). The mean difference in orbital volume between the digitally planned orbit and the postoperative orbit was 29.16 cm3 (SD 3.54, presurgical) to 28.33 cm3 (SD 3.64, postsurgical, t = 5.00, df = 95.00; p < 0.001), resulting in a mean volume difference (planned vs. postop) of less than 1 cm3. A 3D analysis of the color mapping showed minor deviations compared to the mirrored unaffected side. The results suggested that primary reconstruction in complex orbital wall fractures can be routinely achieved with a high degree of accuracy by using selective laser melted orbital PSIs.

Application of Structured-Light 3-D Scanning to the Documentation of Plastic Fingerprint Impressions: A Quality Comparison with Traditional Photography.

Plastic fingerprint impressions found at crime scenes are often too delicate for collection, leaving photography as the best option for documentation. However, traditional photography techniques can be inadequate in documenting minute 3-D details due to limitations of the camera and lighting conditions. This study investigated the feasibility of applying commercially available structured-light 3-D scanners in the documentation of plastic prints. Attempts were made to develop a procedure to extract curvature features from 3-D scanned fingerprints and flatten the friction ridge features into two-dimensional (2-D) images to allow direct comparison with the traditional photography in the CSIpix® Matcher and NFIQ 2.0 software. Two 3-D scanners were evaluated a Dentsply Sirona inEos X5® and an Artec Space Spider. In this study, 3-D scanners demonstrated robustness as well as efficiency in the collection of plastic fingerprint impressions in select substrates. One of the developed methods utilizing a discrete geometry operator and convexity features outperformed traditional photography, achieving higher software detection scores in minutiae count and match quality, while traditional photography could not always capture enough high-quality minutiae for comparisons, even after digital enhancement.

Developing Fall-impact Protection Pad with 3D Mesh Curved Surface Structure using 3D Printing Technology.

In this study, we present the development of fall-impact protection pads for elderly people using three-dimensional (3D) printing technology. To develop fall-impact protection clothing, it is important to maintain the functionality of the protection pad while ensuring that its effectiveness and appearance remain optimal in the process of inserting it. Therefore, this study explores the benefit of exploiting 3D scan data of the human body using 3D printing technology to develop a fall-impact protection pad that is highly suited to the human body shape. The purpose of this study was to present a 3D modeling process for creating curved protective pads comprising a hexagonal mesh with a spacer fabric structure and to verify the impact protection performance by printing curved pads. To this end, we set up a section that includes pads in the 3D human body scan data and extracted body surface information to be applied in the generation of the pad surface. The sheet-shaped hexagonal mesh structure was cut and separated according to the pad outline, and then deformed according to the curved surface of the human body. The pads were printed, and their protection performance was evaluated; a 79.2-81.8% reduction in impact force was observed compared to similar cases in which the pads were not used.

Primary orbital reconstruction with selective laser melted core patient-specific implants: overview of 100 patients.

Contemporary advances in technology have enabled the transfer of industrial laser melting technology to surgery, and its use can improve the accuracy of orbital restoration. The aim of this study therefore was to evaluate the accuracy of primary orbital reconstruction with the use of selective laser melted, patient-specific implants and navigation. A total of 100 patients with complex orbital fractures were included. Planned orbital volumes were compared with those achieved, and angles were compared with the unaffected side. Analysis included the overlay of postoperative on planned images (iPlan® 3.0.5, Brainlab). The mean (SD) orbital volume of the unaffected side was 27.2 (2.8)ml in men and 25.0 (2.6)ml in women. Fractures that involved the posterior third of the orbital floor and comminuted fractures showed significant orbital enlargement (p=0.026). The mean (SD) reconstructed orbital volume was 26.9 (2.7)ml in men and 24.26 (2.5)ml in women. Three-dimensional analysis of the colour mapping showed minor deviations when compared with the unaffected side. The results suggest that a high degree of accuracy can be routinely achieved in these complex cases.

Injectable PLCL/gelatin core-shell nanofibers support noninvasive 3D delivery of stem cells.

Stem cells with their intrinsic ability to differentiate to specific cell types have been clinically used as the most promising cell therapy. However, the injection-based administration in most clinical trials shows cell retention rates as low as 1% within days of transplantation. Herein, core-shell nanofibers of PLCL (Poly(lactide-co-ε-caprolactone)) and Gelatin-Methacrylate (Gel-MA), respectively, were fabricated to support the 3D delivery of human mesenchymal stem cells (hMSCs). The core-shell ratios can be accurately controlled using coaxial electrospinning, achieving smooth sliding fibers with up to 85 wt% of Gel-MA shell. Different core-shell flow rate ratios were systematically investigated. Either an increase of the concentration of the core PLCL solution or an increase of core solution flow rate can lead to an increase of the fiber diameter from 0.26 µm to 1.38 µm, and a decrease of numbers of beads from 33 per 100 fibers to bead-free. Significantly enhanced hMSCs proliferation (~2 folds over 7 days) on the three dimensional (3D) core-shell fibers were observed compared to that on 2D culture. Moreover, hMSCs cellularized 3D core-shell fibers can be directly injected as 4 cm2 meshes through a catheter, with an 80% viable retention after injection, indicating their great promise in advancing stem cell therapy by both improving viable retention and meanwhile allowing minimally invasive administration.

Graphene Oxide-Based Biocompatible 3D Mesh with a Tunable Porosity and Tensility for Cell Culture.

One of the major challenges associated with modeling the influence of the cellular microenvironment on cell growth and differentiation is finding suitable substrates for growing the cells in a manner that recapitulates the cell-cell and cell-microenvironmental interactions in vitro. As one approach to address this challenge, we have developed graphene oxide (GO)-3D mesh with tunable hardness and porosity for application in cell culture systems. The synthetic method of GO-3D mesh is simple, easily reproducible, and low cost. The foundation of the method is the combination of poly(ethylene)(glycol) (PEG) and GO together with a salt-leaching approach (NaCl) in addition to a controlled application of heat during the synthetic process to tailor the mechanical properties, porosity, and pore-size distribution of the resulting GO-3D mesh. With this methodology, the hydrogel formed by PEG and GO generates a microporous mesh in the presence of the NaCl, leading to the formation of a stable 3D scaffold after extensive heating and washing. Varying the ratio of NaCl to GO controls porosity, pore size, and pore connectivity for the GO-3D mesh. When the porosity is less than 90%, with an increasing ratio of NaCl to GO, the number of pores increases with good interconnectivity. The 3D-mesh showed excellent biocompatibility with vascular cells which can take on a morphology comparable to that observed in vessels in vivo. Cell proliferation and gene expression can be determined from cells grown on the GO-3D scaffold, providing a valuable tool for investigating cell-microenvironmental changes. The GO-3D mesh described results from the synergy of the combined chemical properties of the PEG and GO with the salt-leaching methodology to generate a unique and flexible mesh that can be modified and optimized for a variety of in vitro applications.

Endoscopic and histological evaluations of a newly designed inguinal hernia mesh implant: Experimental studies on porcine animal model and human cadaver.

PURPOSE: Conventional prostheses used for inguinal hernia repair are static and passive. This feasibility-study shows the features of a new 3D tension-free prosthesis in an experimental model. METHODS: This study was divided into two-phases: 1) aimed to test the physics intrinsic features and the anatomical adaptability of a new 3D designed mesh, and 2) aimed to evaluate the inflammatory reaction associated with different materials used. On phase-1 implantations were performed in pigs. During the first trial phase, the prostheses were also implanted on human cadavers. On phase-2, implantation was carried out on large swine. Follow-up was of 60-days, after which the animals were anaesthetized for laparoscopic assessment, and for sample collection of mesh implantation site for histological analysis. RESULTS: All animals showed good 3D mesh tolerance, and the follow-up period was uneventful. The laparoscopy showed no inflammatory lesions on the internal surface of the peritoneum. Macroscopic observation of implantation site revealed some local fibrosis and reorganization of tissue, no signs of infection, and no changes on original implant positioning. Histological analysis on phase-1 showed in most sample segments the deferent duct maintaining its central position and surrounded by vascular and nervous structures. On phase-2 differences in inflammatory lesion score could be found between subjects. CONCLUSIONS: This new 3D mesh can be placed appropriately and from this preliminary animal study no untoward complications were noted over a 60 day period.

Anatomy-based 3D skeleton extraction from femur model.

Using 3D models of bones can highly improve accuracy and reliability of orthopaedic evaluation. However, it may impose excessive computational load. This article proposes a fully automatic method for extracting a compact model of the femur from its 3D model. The proposed method works by extracting a 3D skeleton based on the clinical parameters of the femur. Therefore, in addition to summarizing a 3D model of the bone, the extracted skeleton would preserve important clinical and anatomical information. The proposed method has been applied on 3D models of 10 femurs and the results have been evaluated for different resolutions of data.

Biological treatment and modeling aspect of BTEX abatement process in a biofilter.

In the present work, a laboratory scale corn-cob based biofilter inoculated with Bacillus sphaericus (MTCC 8103) was used for degradation of BTEX for a period of 86 days. The overall performance of a biofilter evaluated in terms of its elimination capacity by using 3-D mesh technique. Maximum removal efficiency was found more than 96.43% for all four compounds in each phase of experiments. A maximum elimination capacity (EC) of 60.89 gm(-3)h(-1) of the biofilter was obtained at inlet BTEX load of 63.14 gm(-3)h(-1). The follow-up of carbon dioxide concentration profile through the biofilter revealed that the mass ratio of carbon dioxide produced to the BTEX removed was approximately 2.2, which confirms complete degradation of BTEX. Moreover, BTEX concentration profile along the biofilter depth bed also determined by convection-diffusion reactor (CDR) model.

Recurrence after Repair of Primary Acquired Grynfeltt Hernia

Lumbar hernias are rare posterolateral abdominal wall defects. There are two types of lumbar hernia. One is a superior lumbar hernia through the deep superior orifice (Grynfeltt triangle), and the other is a lower lumbar hernia through the superficial lower orifice (Petit triangle). A lumbar hernia is often misdiagnosed as a lipoma, so a cautious clinical examination is very important. Reports of recurrent lumbar hernia are extremely rare in the literature. We experienced a case of recurrence in an acquired primary lumbar hernia in a 71-year-old male who had undergone mesh-plug herniorrhaphy. The hernia orifice was 1 cm in diameter and exhibited a fibrous smooth margin. Hernia repair using 3-D mesh was performed. The patient had uncomplicated postoperative course and was discharged one day after the operation.