A comprehensive morphometric study of visceral and subcutaneous adipose tissue depots in mice, hamsters and rats / Un estudio morfométrico completo de los depósitos de tejido adiposo visceral y subcutáneo en ratones, hámsters y ratas

SUMMARY: Adipose tissue morphology of different fat tissue depots can be described using the number of adipocytes and cell surface of adipocytes. This study deals with characteristics and morphometric analysis of white and brown adipose tissue depots in healthy adult laboratory mice, hamsters and rats of both sexes. The number of unilocular adipocytes in white adipose tissue differs from one adipose tissue depot to another, with the largest number of adipocytes in mice and a similar number in hamsters and rats. The smallest surface area and the largest percentage of small unilocular adipocytes were found in mice. White adipose tissue in hamsters and rats was predominantly made out of a larger percentage of medium-sized adipocytes and a smaller percentage of small and medium-sized adipocytes. Uncoupling protein 1 positive multilocular adipocytes were found in classic brown adipose tissue depots with larger percentages in mice (93.20 %) and hamsters (91.30 %), while rats had a smaller percentage (78.10 %). In white and brown adipose tissue, significant differences between species and both sexes within the same species were found, indicating the influence of sexual dimorphism. The presented morphometric results could serve as a basis for further studies concerning experimental animal models of metabolic disorders and obesity.

RESUMEN: La morfología del tejido adiposo de diferentes depósitos de tejido graso se puede describir utilizando el número de adipocitos y la superficie celular de los adipocitos. Este estudio analiza las características y el análisis morfométrico de los depósitos de tejido adiposo blanco y marrón en ratones, hamsters y ratas de laboratorio, adultos sanos de ambos sexos. El número de adipocitos uniloculares en el tejido adiposo blanco difiere de un depósito de tejido adiposo a otro, con el mayor número de adipocitos en ratones y un número similar en hámsteres y ratas. La superficie más pequeña y el mayor porcentaje de adipocitos uniloculares pequeños se encontraron en ratones. El tejido adiposo blanco en hámsteres y ratas estaba compuesto predominantemente por un mayor porcentaje de adipocitos de tamaño mediano y un porcentaje menor de adipocitos de tamaño pequeño y mediano. Los adipocitos multiloculares positivos para la proteína desacopladora 1 se encontraron en depósitos de tejido adiposo marrón clásico con mayores porcentajes en ratones (93,20 %) y hámsters (91,30 %), mientras que las ratas tenían un porcentaje menor (78,10 %). En el tejido adiposo blanco y pardo se encontraron diferencias significativas entre especies y entre ambos sexos dentro de una misma especie, lo que indica la influencia del dimorfismo sexual. Los resultados morfométricos presentados podrían servir como base para futuros estudios sobre modelos animales experimentales de trastornos metabólicos y obesidad.

Primo Bundles Identified by Microcomputed Tomography in Primo Vascular Tissue on the Surface of Rat Abdominal Organs.

BACKGROUND: The primo vascular system (PVS) is a novel network composed of primo nodes (PNs) and primo vessels (PVs). Currently, its anatomy is not fully understood. OBJECTIVES: The aim of this study was to elucidate the three-dimensional PN-PV structure. METHODS: Organ-surface PVS tissue was isolated from healthy and anemic rats. The tissues were analyzed by X-ray microcomputed tomography (CT), hematoxylin and eosin staining, and scanning electron microscopy. RESULTS: From CT images, we identified one or more bundles in a PV. In the PN, the bundles were enlarged and existed in isolation and/or in anastomosis. The transverse CT images revealed four areas of distinct intensities: zero, low, intermediate, and high. The first two were considered to be the sinuses and the subvessels of the PVS and were identified in the hematoxylin and eosin-stained PN sections. The enlargement of the PN from anemic rats was associated with an increase in the intermediate-intensity area. The high-intensity area demarcated the bundle and was overlapped with the mesothelial cells. In scanning electron microscopy, the PV bundles branched out, tapering down to a single bundle at some distance from the PN. Each bundle was composed of several subvessels (∼5 µm). Clustered round microcells (1-25 µm), scattered flat oval cells (∼15 µm), and amorphous extracellular matrix were observed on the surface of the PVS tissue. CONCLUSIONS: The results newly showed that the primo bundle is a structural unit of both PVs and PNs. A bundle was demarcated by high CT intensity and mesothelial cells and consisted of multiple subvessels. The PN bundles contained also sinuses.

[The key points to comprehend the pelvic fascia].

Pelvic fascia is considered to be one controversial human anatomic structure. According to the characteristics of specialized surgery, colorectal surgeons, gynecologic surgeons and urologic surgeons respectively marked the pelvic fascia, but the naming is not unified. For some specific anatomic structures (such as pelvic plexus), different scholars have different descriptions of their positions. The lack of standard anatomic terms makes it difficult to understand the corresponding anatomic structures, and also hinders the communication between disciplines. Combined with autopsy research, surgical observation and literature review, we discussed the common puzzles of pelvic clinical anatomy. The main points of this article are as follows. (1) Urogenital fascia and vesicohypogastric fascia are the components of visceral fascia. (2) The visceral fascia and fascia propria of rectum are two separate layers. (3) The pelvic plexus is located on the outside of the confluence of visceral fascia and Denonvilliers' fascia. (4) To understand the pelvic lateral ligament from the perspective of layers. (5) To understand pelvic fascia from a holistic perspective.

Bellymount enables longitudinal, intravital imaging of abdominal organs and the gut microbiota in adult Drosophila.

Cell- and tissue-level processes often occur across days or weeks, but few imaging methods can capture such long timescales. Here, we describe Bellymount, a simple, noninvasive method for longitudinal imaging of the Drosophila abdomen at subcellular resolution. Bellymounted animals remain live and intact, so the same individual can be imaged serially to yield vivid time series of multiday processes. This feature opens the door to longitudinal studies of Drosophila internal organs in their native context. Exploiting Bellymount's capabilities, we track intestinal stem cell lineages and gut microbial colonization in single animals, revealing spatiotemporal dynamics undetectable by previously available methods.

Topography and syntopy of abdominopelvic viscera of the giant anteater (Myrmecophage tridactyla - Linnaeus, 1758) / Topografia e sintopia das vísceras abdominopélvicas do tamanduá-bandeira (Myrmecophage tridactyla - Linnaeus, 1758)

In view of the scarcity of data about the topography and syntopy of abdominopelvic viscera of the giant anteater (Myrmecophage tridactyla - Linnaeus, 1758), the present study aimed to elucidate these characteristics and to compare them with the other animal species, especially the domestic ones. Three specimens, two males and one female, were donated by the Environmental Military Police of Franca to the Anatomy Veterinary Laboratory of the University of Franca, after death by road killings. The animals were fixed and maintained in aqueous 10% formaldehyde solution, followed by conventional dissection of the abdominopelvic cavities for subsequent direct inspection and topographic description of the viscera, aiming at comparative analyzes with other species, whose positioning and particularities are already established in the literature. It was observed that most of the viscera of these cavities have similar location and syntopy to domestic animals, except for the kidneys and testicles. In view of the established methodology and the results obtained, it is accepted that more specimens of anteater, both genera, should be evaluated and registered scientifically to confirm the data of the current research and anatomical preconization of the abdominopelvic cavity, inasmuch anatomical individual variation are possible between animals of the same species.(AU)

Diante da escassez de dados sobre a topografia e a sintopia das vísceras abdominopélvicas do tamanduá-bandeira (Myrmecophage tridactyla - Linnaeus, 1758), o presente estudo teve como objetivo elucidar essas características e compará-las com as demais espécies animais, mormente as domésticas. Utilizaram-se três espécimes, dois machos e uma fêmea, provenientes de doação da Polícia Militar Ambiental de Franca ao Laboratório de Anatomia Veterinária da Universidade de Franca, após óbitos por atropelamentos. Os animais foram fixados e mantidos em solução aquosa de formaldeído a 10%, seguidos de dissecação convencional das cavidades abdominopélvicas para posterior inspeção direta e descrição topográfica das vísceras, visando a análises comparativas com outras espécies, cujo posicionamento e cujas particularidades já são bem estabelecidos na literatura. Observou-se que a maioria das vísceras dessas cavidades possuem localização e sintopia similares aos animais domésticos, exceto os rins e os testículos. Diante da metodologia estabelecida e dos resultados obtidos, admite-se que mais espécimes de tamanduás-bandeiras, de ambos os gêneros, devam ser avaliados e registrados cientificamente, visando à confirmação dos dados da atual pesquisa e à preconização anatômica da cavidade abdominopélvica, visto que variações anatômicas individuais são passíveis entre animais da mesma espécie.(AU)

Total and Regional Body Composition of NCAA Division I Collegiate Baseball Athletes.

This study's purpose was to evaluate total, regional, and throwing versus non-throwing arm body composition measurements between various positions of NCAA Division I male baseball players using dual X-ray absorptiometry (DXA). Two hundred and one collegiate baseball athletes were measured using DXA. Visceral adipose tissue (VAT), total and regional fat mass (FM), lean mass (LM), and bone mineral density (BMD) were measured. Athletes were separated into: pitchers (n=92), catchers (n=25), outfielders (n=43), and infielders (n=41). ANOVA and Tukey's honest significant difference assessed total and regional differences between positions. Infielders had significantly (p<0.05) lower total LM than pitchers and outfielders. Additionally, outfielders had significantly lower total FM compared to pitchers and catchers. No significant differences between positions were observed for total BMD and VAT. Pitchers' and infielders' throwing arm demonstrated significantly greater total mass, FM, LM, and BMD compared to the non-throwing arm. Further, outfielders' throwing arm total mass, LM, and BMD were significantly higher vs. the non-throwing arm. Significant differences were observed in total and regional body composition measurements across position, in addition to differences in throwing arm vs. non-throwing arm composition. These measurement values are important to coaches and trainers as normative positional DXA data for collegiate baseball players.

Real world usability analysis of two augmented reality headsets in visceral surgery.

Recent developments in the field of augmented reality (AR) have enabled new use cases in surgery. Initial set-up of an appropriate infrastructure for maintaining an AR surgical workflow requires investment in appropriate hardware. We compared the usability of the Microsoft HoloLens and Meta 2 head mounted displays (HMDs). Fifteen medicine students tested each device and were questioned with a variant of the System Usability Scale (SUS). Two surgeons independently tested the devices in an intraoperative setting. In our adapted SUS, ergonomics, ease of use, and visual clarity of the display did not differ significantly between HMD groups. The field of view (FOV) was smaller in the Microsoft HoloLens than the Meta 2 and significantly more study subjects (80% vs. 13.3%; P < 0.001) felt limited through the FOV. Intraoperatively, decreased mobility due to the necessity of an AC adapter and additional computing device for the Meta 2 proved to be limiting. Object stability was rated superior in the Microsoft HoloLens than the Meta 2 by our surgeons and lead to increased use. In summary, after examination of the Meta 2 and the Microsoft HoloLens, we found key advantages in the Microsoft HoloLens which provided palpable benefits in a surgical setting.

Revisiting Avicenna's (980-1037 AD) anatomy of the abdominal viscera from the Canon of Medicine.

Avicenna (980-1037 A.D) was the most influential Iranian physician and philosopher in the medieval era. Avicenna composed and compiled treaties on various aspects of medicine in his famous book the Canon of Medicine. Avicenna's treaties have inspired countless debates in all fields of medicine including basic medical sciences. In his treaties, Avicenna adopted the practical approach to the descriptions of the human body and the diseases associated. He made substantial contribution to the medical literature and medical education through his observations and clinical studies. In the current treaties we analysed the anatomy extracts on the topographic and functional anatomy on the abdominal viscera including the gastrointestinal tract presented in the Canon of Medicine and compared to them to extant anatomical textbooks, particularly those adopted in modern curriculums. We found that Avicenna described fairly the anatomy and topographic relations of the abdominal viscera and associated digestive organs. Avicenna's anatomy contributed immensely to the evolution of anatomical sciences and related medical disciplines despite being written 1000 years ago.

Neuroanatomy of Hyalinella punctata: Common patterns and new characters in phylactolaemate bryozoans.

Studies on the bryozoan adult nervous system employing immunocytochemical techniques and confocal laser scanning microscopy are scarce. To gain a better view into the structure and evolution of the nervous system of the Phylactolaemata, the earliest extant branch and sister taxon to the remaining Bryozoa, this work aims to characterize the nervous system of Hyalinella punctata with immunocytochemical techniques and confocal laser scanning microscopy. The cerebral ganglion is located between the anus and the pharynx and contains a lumen. Two ganglionic horns and a circum-oral nerve ring emanate from the cerebral ganglion. The pharynx is innervated by a diffuse neural plexus with two prominent neurite bundles. The caecum is innervated by longitudinal neurite bundles and a peripheral plexus. The intestine is characterized by longitudinal and circular neurite bundles, mostly near the anus. Novel putative sensory cells were found in the foregut and intestine. The tentacle sheath is innervated by a diffuse neural plexus, which emanates from several neurite bundles from the cerebral ganglion, but also parts of the pharyngeal plexus. There are six tentacle neurite bundles of intertentacular origin. The retractor muscles are innervated by two thin neurite bundles. Several characters are described herein for the first time in Phylactolaemata: Longitudinal neurite bundles and a peripheral plexus of the caecum, putative sensory structures of the gut, retractor muscle innervation, specific duplicature band neurite bundles. The tentacle innervation differs from previous descriptions of phylactolaemates regarding the origin of the three abfrontal neurite bundles. In general, most organ systems are innervated by a diffuse plexus in phylactolaemates as opposed to gymnolaemates. In contrast to the Gymnolaemata, representatives of Phylactolaemata show a higher number of tentacle nerves. Although the plesiomorphic condition for zooidal features among bryozoans remains unclear, having a diffuse nerve plexus may represent an ancestral feature for freshwater bryozoans.

Ensino de técnicas de cirurgia cardiovascular na graduação em Medicina utilizando vísceras de suínos / Teaching techniques in cardiovascular surgery for undergraduate students with swine thoracic viscera

OBJETIVO: Apresentar um método prático de ensino e avaliar o grau de eficácia do aprendizado, comparando alunos que passaram pelo curso durante a graduação básica (sétimo semestre) e após 18 meses (décimo semestre), já no internato hospitalar. MÉTODOS: As vísceras conservadas por refrigeração, com coração, estruturas vasculares do mediastino, traqueia e pulmões, foram fixadas em suporte metálico apropriado. Os vasos supra- -aórticos foram ligados, e uma sonda de Foley foi introduzida retrogradamente para a infusão de água, permitindo a apresentação de procedimentos operatórios. Foram aplicados questionários a 40 alunos do sétimo e décimo semestre. As respostas foram submetidas à análise estatística. RESULTADOS: Foram demonstradas técnicas necessárias para o estabelecimento de circulação extracorpórea, confecção de enxerto aorta-coronária com segmento da artéria carótida obtido no mesmo bloco de vísceras, substituição da valva aórtica por prótese valvar sintética, correção de defeito previamente realizado no septo atrial, posicionamento dos vários tipos de eletrodos utilizados para a estimulação elétrica do coração, demonstração de técnicas empregadas para transplante cardíaco, simulação e correção de ferimentos do coração e da aorta. O grau de adequação da ferramenta avaliada foi positivo, com valores entre 55 e 95%, e houve retenção dos ensinamentos após 18 meses. Conclusão: Este método de ensino foi de fácil preparação e baixo custo, permitindo a realização de operações complexas e despertando interesse durante a graduação em Medicina.(AU)

OBJECTIVE: To present this practical teaching method, and assess the degree of learning effectiveness, comparing students who attended the course during basic undergraduation (seventh semester), and after eighteen months (tenth semester), when already in the Hospital internship. METHODS: Thoracic viscera, with heart, vascular structures of the mediastinum, trachea and lungs, preserved by refrigeration, were fixed in a metallic device. The supra-aortic branches were connected, and a Foley catheter was introduced backwards for water infusion, allowing the presentation of surgical procedures. Questionnaires were applied to 40 students of the seventh and tenth semesters; the answers underwent statistical analysis. RESULTS: The following techniques were demonstrated: establishment of cardiopulmonary bypass; coronary artery bypass grafting with carotid artery segment obtained in the same block of viscera; aortic valve replacement with synthetic valve; patch made with biological material in order to correct a defect previously held in the atrial septum; positioning of the various types of electrodes used for electrical stimulation of the heart; demonstration of techniques performed in cardiac transplantation and simulation and correction of both heart and aorta injuries. The degree of adequacy of such tool was positive, with values between 55 and 95%, and retention of what was taught after 18 months. CONCLUSION: This teaching method requires easy preparation and low cost, allowing the performance of complex operations, attracting medical students' interest.(AU)

Microscopic anatomy of the visceral fasciae.

The term 'visceral fascia' is a general term used to describe the fascia lying immediately beneath the mesothelium of the serosa, together with that immediately surrounding the viscera, but there are many types of visceral fasciae. The aim of this paper was to identify the features they have in common and their specialisations. The visceral fascia of the abdomen (corresponding to the connective tissue lying immediately beneath the mesothelium of the parietal peritoneum), thorax (corresponding to the connective tissue lying immediately beneath the mesothelium of the parietal pleura), lung (corresponding to the connective tissue under the mesothelium of the visceral pleura), liver (corresponding to the connective tissue under the mesothelium of the visceral peritoneum), kidney (corresponding to the Gerota fascia), the oesophagus (corresponding to its adventitia) and heart (corresponding to the fibrous layer of the pericardial sac) from eight fresh cadavers were sampled and analysed with histological and immunohistochemical stains to evaluate collagen and elastic components and innervation. Although the visceral fasciae make up a well-defined layer of connective tissue, the thickness, percentage of elastic fibres and innervation vary among the different viscera. In particular, the fascia of the lung has a mean thickness of 134 µm (±â€…21), that of heart 792 µm (±â€…132), oesophagus 105 µm (±â€…10), liver 131 µm (±â€…18), Gerota fascia 1009 µm (±â€…105) and the visceral fascia of the abdomen 987 µm (±â€…90). The greatest number of elastic fibres (9.79%) was found in the adventitia of the oesophagus. The connective layers lying immediately outside the mesothelium of the pleura and peritoneum also have many elastic fibres (4.98% and 4.52%, respectively), whereas the pericardium and Gerota fascia have few (0.27% and 1.38%). In the pleura, peritoneum and adventitia of the oesophagus, elastic fibres form a well-defined layer, corresponding to the elastic lamina, while in the other cases they are thinner and scattered in the connective tissue. Collagen fibres also show precise spatial organisation, being arranged in several layers. In each layer, all the fibrous bundles are parallel with each other, but change direction among layers. Loose connective tissue rich in elastic fibres is found between contiguous fibrous layers. Unmyelinated nerve fibres were found in all samples, but myelinated fibres were only found in some fasciae, such as those of the liver and heart, and the visceral fascia of the abdomen. According to these findings, we propose distinguishing the visceral fasciae into two large groups. The first group includes all the fasciae closely related to the individual organ and giving shape to it, supporting the parenchyma; these are thin, elastic and very well innervated. The second group comprises all the fibrous sheets forming the compartments for the organs and also connecting the internal organs to the musculoskeletal system. These fasciae are thick, less elastic and less innervated, but they contain larger and myelinated nerves. We propose to call the first type of fasciae 'investing fasciae', and the second type 'insertional fasciae'.

Abdominal Visceral to Subcutaneous Adipose Tissue Ratio Is Associated with Increased Risk of Erosive Esophagitis.

BACKGROUND: To investigate the association between abdominal fat distribution represented by the visceral fat area (VFA) to subcutaneous fat area (SFA) ratio, and erosive esophagitis (EE). METHODS: Seven hundred and twenty-eight participants aged >40 years underwent physical examination, blood tests, esophagogastroduodenoscopy, and abdominal computer tomography at Chung-Ang University Hospital from 2007 to 2012. RESULTS: Of 728 subjects, 65 (8.9%) had EE. The EE patients had higher body mass index, metabolic syndrome prevalence, triglyceride levels, and blood pressure (P < 0.05). The mean VFA/SFA ratio was higher in the EE group than in the non-EE group (1.30 vs. 0.92, P < 0.001). The predominance of EE in the group with higher VFA/SFA ratio was higher than in the group with lower VFA/SFA ratio (P < 0.001). A VFA/SFA ratio ≥1.165 had good accuracy to predict EE (area under the receiver-operating characteristic curve, 0.643). The VFA/SFA ratio and visceral fat volume were positively correlated with the severity of EE (P = 0.002), and a VFA/SFA ratio ≥1.165 was strongly correlated with the severity of EE (P < 0.001). CONCLUSION: The high VFA/SFA ratio can be a useful clinical predictor of EE.

Diffusion tensor imaging in abdominal organs.

Initially, diffusion tensor imaging (DTI) was mainly applied in studies of the human brain to analyse white matter tracts. As DTI is outstanding for the analysis of tissue´s microstructure, the interest in DTI for the assessment of abdominal tissues has increased continuously in recent years. Tissue characteristics of abdominal organs differ substantially from those of the human brain. Further peculiarities such as respiratory motion and heterogenic tissue composition lead to difficult conditions that have to be overcome in DTI measurements. Thus MR measurement parameters have to be adapted for DTI in abdominal organs. This review article provides information on the technical background of DTI with a focus on abdominal imaging, as well as an overview of clinical studies and application of DTI in different abdominal regions. Copyright © 2015 John Wiley & Sons, Ltd.

Magnetic susceptibility anisotropy outside the central nervous system.

Magnetic-susceptibility-based MRI has made important contributions to the characterization of tissue microstructure, chemical composition, and organ function. This has motivated a number of studies to explore the link between microstructure and susceptibility in organs and tissues throughout the body, including the kidney, heart, and connective tissue. These organs and tissues have anisotropic magnetic susceptibility properties and cellular organizations that are distinct from the lipid organization of myelin in the brain. For instance, anisotropy is traced to the epithelial lipid orientation in the kidney, the myofilament proteins in the heart, and the collagen fibrils in the knee cartilage. The magnetic susceptibility properties of these and other tissues are quantified using specific MRI tools: susceptibility tensor imaging (STI), quantitative susceptibility mapping (QSM), and individual QSM measurements with respect to tubular and filament directions determined from diffusion tensor imaging. These techniques provide complementary and supplementary information to that produced by traditional MRI methods. In the kidney, STI can track tubules in all layers including the cortex, outer medulla, and inner medulla. In the heart, STI detected myofibers throughout the myocardium. QSM in the knee revealed three unique layers in articular cartilage by exploiting the anisotropic susceptibility features of collagen. While QSM and STI are promising tools to study tissue susceptibility, certain technical challenges must be overcome in order to realize routine clinical use. This paper reviews essential experimental findings of susceptibility anisotropy in the body, the underlying mechanisms, and the associated MRI methodologies. Copyright © 2016 John Wiley & Sons, Ltd.

La anatomía y las prácticas adivinatorias en las antiguas civilizaciones / Anatomy and divination practices inancient civilizations

Se describe la relación de la anatomía con la aruspicina, también conocida como hieroscopia y extispicina. Se trata del método de adivinar, examinado las vísceras de un animal sacrificado e interpretando detalles de esta anatomía macroscópica con el fin de predecir el futuro, siempre ligado a una voluntad divina. Eran las antiguas civilizaciones las que practicaban este arte supersticioso de adivinar basados en la conformación anatómica que presentaban dichas vísceras. Por estas razones, es muy probable que estos individuos hayan desarrollado un notable conocimiento de la anatomía y que hayan utilizado una terminología anatómica propia que hoy desconocemos por falta de documentación.

The relation between anatomy with haruspicina (also called hieroscopia and extispicina) is described. This is the method to guess, examined the entrails of a slaughtered animal and interpreting details of this gross anatomy in order to predict the future, always linked to a divine will. Ancient civilizations were those who practiced this art to guess superstitious based on anatomical conformation presenting these viscera. For these reasons, it is likely that these individuals have developed considerable knowledge of anatomy and have their own anatomical terminology used today unknown for lack of documentation.

Development of Four Dimensional Human Model that Enables Deformation of Skin, Organs and Blood Vessel System During Body Movement - Visualizing Movements of the Musculoskeletal System.

We constructed a four dimensional human model that is able to visualize the structure of a whole human body, including the inner structures, in real-time to allow us to analyze human dynamic changes in the temporal, spatial and quantitative domains. To verify whether our model was generating changes according to real human body dynamics, we measured a participant's skin expansion and compared it to that of the model conducted under the same body movement. We also made a contribution to the field of orthopedics, as we were able to devise a display method that enables the observer to more easily observe the changes made in the complex skeletal muscle system during body movements, which in the past were difficult to visualize.

Tissue segmentation: a crucial tool for quantitative MRI and visualization of anatomical structures.

Automatic or semi-automatic segmentation of tissue types or organs is well established for X-ray-based computed tomography, with its fixed grey-scale and tissue classes with well-established ranges of Hounsfield units. MRI is much more powerful with regard to soft tissue contrast and quantitative assessment of tissue properties (e.g., perfusion, diffusion, fat content), but the principle of signal generation and recording in MRI leads to inherent problems if simple threshold based segmentation procedures are applied. In this editorial in the special issue of MAGMA on tissue segmentation, a number of relevant methodical, scientific, and clinical aspects of reliable tissue segmentation using data recording by MRI are reported and discussed.

[3D modeling of the female pelvis by Computer-Assisted Anatomical Dissection: Applications and perspectives]. / Modélisation anatomique 3D du pelvis féminin par dissection anatomique assistée par ordinateur : applications et perspectives.

OBJECTIVES: To achieve a 3D vectorial model of a female pelvis by Computer-Assisted Anatomical Dissection and to assess educationnal and surgical applications. MATERIALS AND METHOD: From the database of "visible female" of Visible Human Project(®) (VHP) of the "national library of medicine" NLM (United States), we used 739 transverse anatomical slices of 0.33mm thickness going from L4 to the trochanters. The manual segmentation of each anatomical structures was done with Winsurf(®) software version 4.3. Each anatomical element was built as a separate vectorial object. The whole colored-rendered vectorial model with realistic textures was exported in 3Dpdf format to allow a real time interactive manipulation with Acrobat(®) pro version 11 software. RESULTS: Each element can be handled separately at any transparency, which allows an anatomical learning by systems: skeleton, pelvic organs, urogenital system, arterial and venous vascularization. This 3D anatomical model can be used as data bank to teach of the fundamental anatomy. CONCLUSION: This 3D vectorial model, realistic and interactive constitutes an efficient educational tool for the teaching of the anatomy of the pelvis. 3D printing of the pelvis is possible with the new printers.

Nonlinear Difference Imaging Approach to Three-Dimensional Electrical Impedance Tomography in the Presence of Geometric Modeling Errors.

OBJECTIVE: To evaluate the recently proposed nonlinear difference imaging approach to electrical impedance tomography (EIT) in realistic 3-D geometries. METHODS: In this paper, the feasibility of nonlinear difference approach-based EIT is tested using simulation studies in 3-D geometries of thorax and larynx, and with an experimental study of a thorax-shaped water tank. All test cases exhibit severe modeling errors due to uncertainty in the boundary shape of the body. RESULTS: In all test cases, the conductivity change reconstructed with nonlinear difference imaging outperforms the conventional reconstructions qualitatively and quantitatively. CONCLUSION: The results demonstrate that the nonlinear difference reconstructions tolerate geometrical modeling errors at least to the same extent as the conventional linear approach and produce quantitatively more accurate information on the conductivity change. SIGNIFICANCE: Physiological processes that produce changes in the electrical conductivity of the body can be monitored with difference imaging based on EIT. The wide popularity of linearized difference imaging in EIT is mainly based on its good tolerance for the ubiquitous modeling errors, which are predominantly caused by inexact knowledge of the body geometry. However, the linearized difference imaging produces only qualitative information on the conductivity change, and the feasibility of the estimates also depends on the selection of the linearization point which ideally should be equal to the conductivity of the initial state. Based on the findings of this paper, these problems can be avoided by nonlinear difference imaging, and potentially the approach can enable quantitative imaging of conductivity change in medical applications.

Morphology of the Canine Omentum Part 1: Arterial Landmarks that Define the Omentum.

Although the omentum remains an enigmatic organ, research during the last decades has revealed its fascinating functions including fat storage, fluid drainage, immune activity, angiogenesis and adhesion. While clinicians both in human and veterinary medicine are continuously exploring new potential omental applications, detailed anatomical data on the canine omentum are currently lacking, and information is often retrieved from human medicine. In this study, the topographic anatomy of the canine greater and lesser omentum is explored in depth. Current nomenclature is challenged, and a more detailed terminology is proposed. Consistent arteries that are contained within folds of the superficial omental wall are documented, described and named, as they can provide the anatomical landmarks that are necessary for unambiguous scientific communication on the canine omentum. In an included dissection video, the conclusions and in situ findings described in this study are demonstrated.