Communication, collaboration and contagion: "Virtualisation" of anatomy during COVID-19

COVID-19 has generated a global need for technologies that enable communication, collaboration, education and scientific discourse whilst maintaining physical distance. University closures due to COVID-19 and physical distancing measures disrupt academic activities that previously occurred face-to-face. Restrictions placed on universities due to COVID-19 have precluded most conventional forms of education, assessment, research and scientific discourse. Anatomists now require valid, robust and easy-to-use communication tools to facilitate remote teaching, learning and research. Recent advances in communication, video conferencing and digital technologies may facilitate continuity of teaching and research activities. Examples include highly-interactive video conferencing technology, collaborative tools, social media and networking platforms. In this narrative review, we examine the utility of these technologies in supporting effective communication and professional activities of anatomists during COVID-19 and after.

Determination of whether morphometric analysis of vertebrae in the domestic cat (Felis catus) is related to sex or skull shape

In many mammals, gender and skull shape are related to the bone morphology of the entire body; however, this has not been well established in the domestic cat (Felis catus). This study aims to find a relationship between cervical, thoracic and lumbar vertebrae morphometrics with regard to the sex and skull shape of domestic cats. A total of 79 samples obtained from 92 dried bones of domestic cats were used to determine morphometric measurements for a total of 29 parameters. Hierarchical clustering was used to cluster the vertebral bones found in three groups: C3-T1, T2-T11 and T12-L7. The skull shape identification process employed discriminative analysis and revealed the highest training data accuracy rate at up to 86.20% in T4 followed by L1 (86.04%) Axis (85.71%) and C5 (85.18%). Sex identification employed discriminative analysis and displayed the highest training data accuracy rate at up to 75.58% in L1 followed by, T7 (71.87%) and C6 (71.79%). Moreover, we found that 14% of the samples had one vertebra missing (T13 or L1). In conclusion, domestic cat vertebral morphometrics were found to be more related to skull shape than gender. In addition, bone clustering employed morphometric data and yielded a result that was similar to that of traditional cluster analysis involving body regions.

Sex-based differences in human sacroiliac joint shape: a three-dimensional morphological analysis of the iliac auricular surface of modern Japanese macerated bones

The human pelvis is one of the skeletons where sex differences are expressed, but few detailed studies have been conducted on sex-related differences in the sacroiliac joint morphology. Therefore, we conducted a three-dimensional morphological analysis evaluation of the sacroiliac joints to clarify the sex-related difference of the joint's morphology. Right-side macerated innominate bones of Japanese males (n = 100) and females (n = 70) whose ages at death were recorded were included in the study. Three-dimensional images were created from the subjects' iliac auricular surface images, and 16 measurement parameters were acquired on the basis of 11 defined measurement points. All measurement parameters were compared between the male and female groups. The values of the measurement parameters indicating the size of the iliac auricular surface were significantly larger in the male group than in the female group. In addition, the angle between the short and long arms of the auricular surface was larger in the male group. Furthermore, on the basis of the corrected values of the physical disparity, the long arm dimension of the iliac auricular surface was larger in the male group, while the short arm dimension was larger in the female group. The sex-based differences in the iliac auricular surface morphology that were confirmed in this study may reflect the sex-based differences in the sacroiliac joint function. The findings of this study may contribute to the elucidation of the pathophysiology of the sacroiliac joint dysfunction that frequently occurs in women.

A concise survey on 3D modeling in the science of anatomy

This report provides a concise overview of the rendering and utilization of three-dimensional models in the field of anatomy. Anatomical three-dimensional virtual models are widely used for educational purposes, preoperative planning, and surgical simulations because they simply allow for interactive three-dimensional navigation across the human organs or entire body. Virtual three-dimensional models have been recently fabricated as accurate replicas of the anatomical structures thanks to advances in rapid prototyping technology.

Enchanted nature, dissected nature: the case of Galen's anatomical theology

Through the historical portrait of Galen, I argue that even an enchanted nature does not prevent the performance of violence against nature. Galen (129-c. 216 CE), the great physician-philosopher of antiquity, is best known for his systematization and innovation of the Hippocratic medical tradition, whose thought was the reigning medical orthodoxy from the medieval period into the Renaissance. His works on anatomy were the standard that Vesalius' works on anatomy overturned. What is less known about Galen's study of anatomy, however, is its philosophical and theological edge. In this paper, I show that it is precisely because nature is enchanted that Galen undertakes the grisly practices of anatomical dissection and vivisection, which entail violence against nature. First, I illustrate the violent character of Galen's anatomical experiments. Second, I elucidate Galen's anatomical methodology as a form of philosophizing and theologizing with a scalpel. Third, I explicate the importance of the demonstration of divine teleology that anatomical dissection reveals. Fourth, I sketch how anatomical dissection as a way of knowing nature and God becomes a kind of anatomical, liturgical theology. I conclude that, at least for Galen, an enchanted nature is not in itself exempt from violence.

Re-enchanting the body: overcoming the melancholy of anatomy

I argue here that Weberian disenchantment is manifest in the triumph of instrumental reason and the expansion of analytic enquiry, which now dominates not simply those sciences upon which medicine depends, but medical practice itself. I suggest ways that analytic enquiry, also referred to here as anatomical reasoning, are part of a particular ideology-a way of seeing, speaking about, and inhabiting the world-that often fails to serve the health of patients because it is incapable of "seeing" them in the moral sense described by Iris Murdoch and others. I use the work of James Elkins and Wendell Berry to call for the recovery of a way of seeing the human body as both other and more than an object of scientific enquiry and social control.

Johann Gottlieb Walter (1734-1818) and the technical preparation of bones in an anatomical cabinet in the late eighteenth and nineteenth century

This study aims to analyze Johann Gottlieb Walter's biography (1734-1818), a German physician that specialized in human anatomy, who received an award of the Göttingen Royal Academy of Sciences. Here, we describe his technique of preparing bones for educational purposes through the comparison of other widely used techniques. The article also focuses on the great historical, scientific and didactic values of the anatomical preparations. In Europe during the eighteenth century the activity of some anatomists and physiologists, who were dedicated to the realization of anatomical preparations, testified the progress of medicine in the study of the human body, fundamental knowledge for physician training.

A lucky mistake: the splenic glands of Marcello Malpighi

Marcello Malpighi (1628-1694) is one of the most important anatomists and physicians in the history of medicine. His contributions to the understanding of human anatomy and physiology span from the first description of capillary circulation to a thorough analysis of the structure and function of body glands. Malpighi believed that most organs consisted of glandular structures, whose distribution and microscopic features determine each organ-specific function. He also applied this view to the study of spleen anatomy, which he recognized as composed of 2 distinct anatomic compartments (ie, the red and the white pulp). Malpighi's observations on the structure and function of the spleen were first published in 1666 in De Viscerum Structura. In this paper, we pay tribute to this work, presenting Malpighi's theory of the spleen as a glandular organ. The rationale of Malpighi's view and its value for contemporary pathologists and medical researchers will also be elucidated.

Cloud-Based Evaluation of Anatomical Structure Segmentation and Landmark Detection Algorithms: VISCERAL Anatomy Benchmarks

Variations in the shape and appearance of anatomical structures in medical images are often relevant radiological signs of disease. Automatic tools can help automate parts of this manual process. A cloud-based evaluation framework is presented in this paper including results of benchmarking current state-of-the-art medical imaging algorithms for anatomical structure segmentation and landmark detection: the VISCERAL Anatomy benchmarks. The algorithms are implemented in virtual machines in the cloud where participants can only access the training data and can be run privately by the benchmark administrators to objectively compare their performance in an unseen common test set. Overall, 120 computed tomography and magnetic resonance patient volumes were manually annotated to create a standard Gold Corpus containing a total of 1295 structures and 1760 landmarks. Ten participants contributed with automatic algorithms for the organ segmentation task, and three for the landmark localization task. Different algorithms obtained the best scores in the four available imaging modalities and for subsets of anatomical structures. The annotation framework, resulting data set, evaluation setup, results and performance analysis from the three VISCERAL Anatomy benchmarks are presented in this article. Both the VISCERAL data set and Silver Corpus generated with the fusion of the participant algorithms on a larger set of non-manually-annotated medical images are available to the research community.

The development of anatomy: from macroscopic body dissections to stem cell-derived organoids

Anatomy as a descriptive topic of research and instruction in medicine has been increasingly influenced by discoveries in molecular cell and developmental biology and most recently the advent of human induced pluripotent stem cells and organoids. We summarize here how anatomy has been influenced by developmental and stem cell biologists, and how in vitro modelling of the three-dimensional body environment is emerging to understand structure and function of cells during differentiation processes in development and disease.

Repeatability, Reproducibility, Separative Power and Subjectivity of Different Fish Morphometric Analysis Methods

We compared the repeatability, reproducibility (intra- and inter-measurer similarity), separative power and subjectivity (measurer effect on results) of four morphometric methods frequently used in ichthyological research, the "traditional" caliper-based (TRA) and truss-network (TRU) distance methods and two geometric methods that compare landmark coordinates on the body (GMB) and scales (GMS). In each case, measurements were performed three times by three measurers on the same specimen of three common cyprinid species (roach Rutilus rutilus (Linnaeus, 1758), bleak Alburnus alburnus (Linnaeus, 1758) and Prussian carp Carassius gibelio (Bloch, 1782)) collected from three closely-situated sites in the Lake Balaton catchment (Hungary) in 2014. TRA measurements were made on conserved specimens using a digital caliper, while TRU, GMB and GMS measurements were undertaken on digital images of the bodies and scales. In most cases, intra-measurer repeatability was similar. While all four methods were able to differentiate the source populations, significant differences were observed in their repeatability, reproducibility and subjectivity. GMB displayed highest overall repeatability and reproducibility and was least burdened by measurer effect. While GMS showed similar repeatability to GMB when fish scales had a characteristic shape, it showed significantly lower reproducability (compared with its repeatability) for each species than the other methods. TRU showed similar repeatability as the GMS. TRA was the least applicable method as measurements were obtained from the fish itself, resulting in poor repeatability and reproducibility. Although all four methods showed some degree of subjectivity, TRA was the only method where population-level detachment was entirely overwritten by measurer effect. Based on these results, we recommend a) avoidance of aggregating different measurer's datasets when using TRA and GMS methods; and b) use of image-based methods for morphometric surveys. Automation of the morphometric workflow would also reduce any measurer effect and eliminate measurement and data-input errors.

Size, shape, and form: concepts of allometry in geometric morphometrics

Allometry refers to the size-related changes of morphological traits and remains an essential concept for the study of evolution and development. This review is the first systematic comparison of allometric methods in the context of geometric morphometrics that considers the structure of morphological spaces and their implications for characterizing allometry and performing size correction. The distinction of two main schools of thought is useful for understanding the differences and relationships between alternative methods for studying allometry. The Gould-Mosimann school defines allometry as the covariation of shape with size. This concept of allometry is implemented in geometric morphometrics through the multivariate regression of shape variables on a measure of size. In the Huxley-Jolicoeur school, allometry is the covariation among morphological features that all contain size information. In this framework, allometric trajectories are characterized by the first principal component, which is a line of best fit to the data points. In geometric morphometrics, this concept is implemented in analyses using either Procrustes form space or conformation space (the latter also known as size-and-shape space). Whereas these spaces differ substantially in their global structure, there are also close connections in their localized geometry. For the model of small isotropic variation of landmark positions, they are equivalent up to scaling. The methods differ in their emphasis and thus provide investigators with flexible tools to address specific questions concerning evolution and development, but all frameworks are logically compatible with each other and therefore unlikely to yield contradictory results.

Anatomical Mercury: Changing Understandings of Quicksilver, Blood, and the Lymphatic System, 1650-1800

The use of mercury as an injection mass in anatomical experiments and preparations was common throughout Europe in the long eighteenth century, and refined mercury-injected preparations as well as plates of anatomical mercury remain today. The use and meaning of mercury in related disciplines such as medicine and chemistry in the same period have been studied, but our knowledge of anatomical mercury is sparse and tends to focus on technicalities. This article argues that mercury had a distinct meaning in anatomy, which was initially influenced by alchemical and classical understandings of mercury. Moreover, it demonstrates that the choice of mercury as an anatomical injection mass was deliberate and informed by an intricate cultural understanding of its materiality, and that its use in anatomical preparations and its perception as an anatomical material evolved with the understanding of the circulatory and lymphatic systems. By using the material culture of anatomical mercury as a starting point, I seek to provide a new, object-driven interpretation of complex and strongly interrelated historiographical categories such as mechanism, vitalism, chemistry, anatomy, and physiology, which are difficult to understand through a historiography that focuses exclusively on ideas.

Anatomical hepatic resection of segment VIII with preoperative 3-dimensional volumetry using SYNAPSE VINCENT and ultrasound-guided vessel compression: report of a case

We report a case of 90-year-old patient who underwent preoperative 3-dimensional (3D) computed tomography (CT) volumetric analysis using SYNAPSE VINCENT imaging software and anatomical resection of segment VIII using ultrasound-guided vessel compression. Preoperative abdominal CT revealed a liver mass measuring 5.0 cm in diameter, and the patient was diagnosed with hepatocellular carcinoma. Liver function was preserved. Preoperative 3D volumetry using SYNAPSE VINCENT revealed the volume of the entire liver to be 1,339 mL and the volume of segment VIII to be 327 mL. Anatomical hepatic resection of segment VIII was performed using ultrasound-guided vessel compression. Operative duration was 372 min and estimated blood loss was 760 mL. Resected liver volume was 290 g. The patient's postoperative course was uneventful, and there has been no evidence of recurrence since the surgery.

How early can we predict Alzheimer's disease using computational anatomy?

Computational anatomy with magnetic resonance imaging (MRI) is well established as a noninvasive biomarker of Alzheimer's disease (AD); however, there is less certainty about its dependency on the staging of AD. We use classical group analyses and automated machine learning classification of standard structural MRI scans to investigate AD diagnostic accuracy from the preclinical phase to clinical dementia. Longitudinal data from the Alzheimer's Disease Neuroimaging Initiative were stratified into 4 groups according to the clinical status-(1) AD patients; (2) mild cognitive impairment (MCI) converters; (3) MCI nonconverters; and (4) healthy controls-and submitted to a support vector machine. The obtained classifier was significantly above the chance level (62%) for detecting AD already 4 years before conversion from MCI. Voxel-based univariate tests confirmed the plausibility of our findings detecting a distributed network of hippocampal-temporoparietal atrophy in AD patients. We also identified a subgroup of control subjects with brain structure and cognitive changes highly similar to those observed in AD. Our results indicate that computational anatomy can detect AD substantially earlier than suggested by current models. The demonstrated differential spatial pattern of atrophy between correctly and incorrectly classified AD patients challenges the assumption of a uniform pathophysiological process underlying clinically identified AD.

A semi-automated approach for anatomical ontology mapping

This paper presents a study in the domain of semi-automated and fully-automated ontology mapping. A process for inferring additional cross-ontology links within the domain of anatomical ontologies is presented and evaluated on pairs from three model organisms. The results of experiments performed with various external knowledge sources and scoring schemes are discussed.

Acrylic resin injection method for blood vessel investigations

The injection of acrylic resin into vessels is an excellent method for macroscopically and microscopically observing their three-dimensional features. Conventional methods can be enhanced by removal of the polymerization inhibitor (hydroquinone) without requiring distillation, a consistent viscosity of polymerized resin, and a constant injection pressure and speed. As microvascular corrosion cast specimens are influenced by viscosity, pressure, and speed changes, injection into different specimens yields varying results. We devised a method to reduce those problems. Sodium hydroxide was used to remove hydroquinone from commercial methylmethacrylate. The solid polymer and the liquid monomer were mixed using a 1 : 9 ratio (low-viscosity acrylic resin, 9.07 ± 0.52 mPa•s) or a 3:7 ratio (high-viscosity resin, 1036.33 ± 144.02 mPa•s). To polymerize the acrylic resin for injection, a polymerization promoter (1.0% benzoyl peroxide) was mixed with a polymerization initiator (0.5%, N, N-dimethylaniline). The acrylic resins were injected using a precise syringe pump, with a 5-mL/min injection speed and 11.17 ± 1.60 mPa injection pressure (low-viscosity resin) and a 1-mL/min injection speed and 58.50 ± 5.75 mPa injection pressure (high-viscosity resin). Using the aforementioned conditions, scanning electron microscopy indicated that sufficient resin could be injected into the capillaries of the microvascular corrosion cast specimens.

A machine learning approach for identifying anatomical locations of actionable findings in radiology reports

Recognizing the anatomical location of actionable findings in radiology reports is an important part of the communication of critical test results between caregivers. One of the difficulties of identifying anatomical locations of actionable findings stems from the fact that anatomical locations are not always stated in a simple, easy to identify manner. Natural language processing techniques are capable of recognizing the relevant anatomical location by processing a diverse set of lexical and syntactic contexts that correspond to the various ways that radiologists represent spatial relations. We report a precision of 86.2%, recall of 85.9%, and F(1)-measure of 86.0 for extracting the anatomical site of an actionable finding. Additionally, we report a precision of 73.8%, recall of 69.8%, and F(1)-measure of 71.8 for extracting an additional anatomical site that grounds underspecified locations. This demonstrates promising results for identifying locations, while error analysis reveals challenges under certain contexts. Future work will focus on incorporating new forms of medical language processing to improve performance and transitioning our method to new types of clinical data.

[The application of stereology in radiology imaging and cell biology fields]

Stereology is an interdisciplinary method for 3D morphological study developed from mathematics and morphology. It is widely used in medical image analysis and cell biology studies. Because of its unbiased, simple, fast, reliable and non-invasive characteristics, stereology has been widely used in biomedical areas for quantitative analysis and statistics, such as histology, pathology and medical imaging. Because the stereological parameters show distinct differences in different pathology, many scholars use stereological methods to do quantitative analysis in their studies in recent years, for example, in the areas of the condition of cancer cells, tumor grade, disease development and the patient's prognosis, etc. This paper describes the stereological concept and estimation methods, also illustrates the applications of stereology in the fields of CT images, MRI images and cell biology, and finally reflects the universality, the superiority and reliability of stereology.

Introduction to stereology

Just as astrology became astronomy and alchemy became chemistry through the application of mathematics, descriptive anatomy can be expected to become more and more quantitative in nature. This article describes the basics of stereology, which provides meaningful quantitative descriptions of the geometry of three-dimensional (3D) structures from measurements that are made on two-dimensional (2D) images. With precise mathematical descriptions such as those that can be obtained with unbiased stereological techniques, it will be possible to make concise descriptions of the relationships between structure and function, of the dynamics of structure, and to reassert the importance of quantitative morphology as an essential part of the evaluation of biological tissues.

A plea for the use of drawing in human anatomy teaching

Descriptive human anatomy constitutes one of the main parts of the educational program of the first part of the medical studies. Professors of anatomy have to take into account the exponential evolution of the techniques of morphological and functional exploration of the patients, and the trend to open more and more the contents of the lectures of anatomy to clinical considerations. Basically, teaching requires a series of descriptive and educational media to set up, in front of the student, the studied structures and so to build the human body. More generally, lectures in morphological sciences try to develop three types of knowledge: declarative, procedural, and conditional. Traditionally in France "basic or first" anatomy is taught in amphitheater and in big groups by building each structure or region on a blackboard with colored chalk that allows a relief stake of certain structures and builds in two dimensions a three-dimensional organization. Actually, the blackboard is and stays for us an excellent media of non-verbal expression.

Elliptical Fourier descriptors for contours in three dimensions: a new tool for morphometrical analysis in biology

Elliptical Fourier descriptor analysis is a method for the morphometric study of curves. It has been used in the two-dimensional plane for closed contours, but rarely for lines in the three-dimensional space. The method consists of an expansion of a contour as a sum of ellipses. In this article, we study three-dimensional contours, i.e. lines embedded in the three-dimensional space. We compute for the first time the relations between the Fourier coefficients and its geometric parameters. We then use these relations for normalization and reorientation of three-dimensional contours. Such an algorithm can be used to perform inter-individual comparisons between contours, regardless of differences in viewpoint or global size. Human and small animal illustrative examples using biomedical X-ray CT imaging data of open bone structures demonstrate the interest and potential of the method for morphological analysis.

[Effect of large-scale repair work on indoor formaldehyde levels upon and subjective symptoms in, medical students during gross anatomy dissection course]

OBJECTIVES

To examine the effect of large-scale repair work on indoor formaldehyde (FA) levels and subjective symptoms in medical students during a gross anatomy dissection course.

METHODS

We measured the indoor FA levels, room air temperature, and room humidity during a gross anatomy dissection course. In addition, the prevalence of subjective symptoms, keeping allergy state, and wearing personal protective equipment were surveyed in two groups of students using a self-administered questionnaire.

RESULTS

The mean indoor FA levels before and after repair work were 1.22 ppm and 0.14 ppm, respectively. The mean indoor FA level significantly decreased after repair work. The prevalences of most subjective symptoms before the anatomy practice were similar before and after the repair work. However, the prevalences of most subjective symptoms during the anatomy practice were lower after the repair work.

CONCLUSIONS

The mean indoor FA levels and prevalences of subjective symptoms decreased after the repair work. We have to continuously monitor indoor FA levels, carry out private countermeasures to minimize exposure to FA, and maintain equipment for ventilation to be able to conduct practice in a comfortable environment.

An unusual course of the thoracic duct in relation to the vertebral vessels

A variation in the course of the thoracic duct was found in the cervical portion of a male cadaver during routine dissection of the head and neck region for undergraduate students. The thoracic duct, while arching laterally above the clavicle, was coursing posterior to the vertebral vein but anterior to the vertebral artery; it normally passes anterior to both the vertebral vein and artery. To the best of our knowledge, this variation in relation to the vertebral vein has not yet been reported. In addition, after coursing posterior to the vertebral vein, the thoracic duct divided into two branches that drained separately, one at the angle between the internal jugular vein and subclavian vein, and the other into the subclavian vein. Knowledge of these variations is essential in order to prevent injury to the thoracic duct while performing surgeries at the root of the neck.

Enhancement of the focal depth in anatomical photography

Limited depth of field is one of the crucial disadvantages of macro photography because some details of the imagined object are blurred. This paper presents the benefits of using an algorithm which enhances focal depth in the close-up views of anatomical structures. The applied technique was based on combining a set of images of the same object (temporal bone) taken on different focal planes. In effect, a single image was generated which presented all details sharply across the photographed object. The extended depth of field of the composite image was reconstructed by CombineZP Image Stacking Software.

Policy needs and options for a common approach towards modelling and simulation of human physiology and diseases with a focus on the virtual physiological human

Life is the result of an intricate systemic interaction between many processes occurring at radically different spatial and temporal scales. Every day, worldwide biomedical research and clinical practice produce a huge amount of information on such processes. However, this information being highly fragmented, its integration is largely left to the human actors who find this task increasingly and ever more demanding in a context where the information available continues to increase exponentially. Investments in the Virtual Physiological Human (VPH) research are largely motivated by the need for integration in healthcare. As all health information becomes digital, the complexity of health care will continue to evolve, translating into an ever increasing pressure which will result from a growing demand in parallel to limited budgets. Hence, the best way to achieve the dream of personalised, preventive, and participative medicine at sustainable costs will be through the integration of all available data, information and knowledge.

A gross anatomy ontology for hymenoptera

Hymenoptera is an extraordinarily diverse lineage, both in terms of species numbers and morphotypes, that includes sawflies, bees, wasps, and ants. These organisms serve critical roles as herbivores, predators, parasitoids, and pollinators, with several species functioning as models for agricultural, behavioral, and genomic research. The collective anatomical knowledge of these insects, however, has been described or referred to by labels derived from numerous, partially overlapping lexicons. The resulting corpus of information--millions of statements about hymenopteran phenotypes--remains inaccessible due to language discrepancies. The Hymenoptera Anatomy Ontology (HAO) was developed to surmount this challenge and to aid future communication related to hymenopteran anatomy. The HAO was built using newly developed interfaces within mx, a Web-based, open source software package, that enables collaborators to simultaneously contribute to an ontology. Over twenty people contributed to the development of this ontology by adding terms, genus differentia, references, images, relationships, and annotations. The database interface returns an Open Biomedical Ontology (OBO) formatted version of the ontology and includes mechanisms for extracting candidate data and for publishing a searchable ontology to the Web. The application tools are subject-agnostic and may be used by others initiating and developing ontologies. The present core HAO data constitute 2,111 concepts, 6,977 terms (labels for concepts), 3,152 relations, 4,361 sensus (links between terms, concepts, and references) and over 6,000 text and graphical annotations. The HAO is rooted with the Common Anatomy Reference Ontology (CARO), in order to facilitate interoperability with and future alignment to other anatomy ontologies, and is available through the OBO Foundry ontology repository and BioPortal. The HAO provides a foundation through which connections between genomic, evolutionary developmental biology, phylogenetic, taxonomic, and morphological research can be actualized. Inherent mechanisms for feedback and content delivery demonstrate the effectiveness of remote, collaborative ontology development and facilitate future refinement of the HAO.

Partition-based mass clustering of tractography streamlines

We describe a novel scalable clustering framework for streamlines obtained from diffusion tractography. Clustering is an attractive means of segmenting a large set of streamlines into anatomically relevant bundles. For most existing methods, however, the large datasets produced in high resolution or multiple subject studies are problematical. To achieve good scalability, our method repeatedly divides the data into subsets, which are then partitioned using hierarchical clustering. A final partition is obtained by recombining the subsets. In addition, the recombination scheme provides a consistency measure for cluster assignment of individual streamlines, which is used to clean up the final result. The clusters have good anatomical plausibility and we show that three clusters corresponding to the three known segments of the arcuate fasciculus show excellent agreement with literature. A major advantage of the method is the fact that it can find clusters in datasets of essentially arbitrary size. This fact is exploited to find consistent clusters in concatenated tractography data from multiple subjects. We expect the identification of bundles across subjects to be an important application of the method.

Visualizing fetal mouse great blood vessels by plastic casting

In this protocol, the great vessels of the mouse are visualized by injecting colored plastic solutions directly into the heart, thereby filling the vessels. The plastic solidifies to create a stable cast that is then revealed by removing the mouse tissues with a caustic. This protocol can be modified for casting the vasculature of other organs by altering the delivery of the liquid plastic. For example, plastic casts of the maternal and fetal vasculature of the placenta can be generated.

The supratrochlear foramen of the humerus and its relation to the medullary canal: a potential surgical application

BACKGROUND

The supratrochlear foramen of the humerus is located at the septum separating the coronoid from the olecranon fossa. Beyond its anthropologic interest, that trait seems to have clinical significance as well.

MATERIAL/METHODS

The supratrochlear foramen was studied in 240 macerated adult humeri. The foramen was recorded in each sex and each side. We attempted to enlighten the likely relation of the foramen with the inferior edge of the medullary canal, as well as that of the dimensions of that canal of humerus and compare it to contralateral humeri without foramen.

RESULTS

The medullary canal width at the entry point of a retrograde intramedullary nail was statistically smaller in humeri with foramen than in humeri without it. Furthermore, the medullary canal of the humeri with foramen ends more proximally than the canal of nonforamen humeri.

CONCLUSIONS

In cases of humeral fractures of the supratrochlear foramen, the surgeon must keep in mind that it is better to perform an antegrade medullary nailing than a retrograde one; as there is higher chance of a secondary fracture, due to the extreme narrowness of the canal at the distal portion of humeri with the supratrochlear foramen.

Anatomy and anatomists in Tuscany in the 17th century

The 17th century was characterized by a real revolution in the field of scientific research due to the introduction of the experimental method, promoted by Galileo Galilei who was the most representative scientist of this period. Therefore, medical disciplines, particularly Anatomy, underwent innovative and deep changes shattering traditional culture and representing the background for the modern science. In this fermenting period, Tuscany played a significant role since numerous distinguished scientists were gathered by Medici Grand Dukes (especially Ferdinando the 2nd and Cosimo the 3rd) at Pisa University and at their court in Florence. Among them, it must be mentioned Giovanni Alfonso Borelli, creator of iathromechanics, Marcello Malpighi, founder of microscopic Anatomy, Francesco Redi, who denied the insect spontaneous generation, Nils Steensen who continued in Florence his anatomical studies on lymph nodes and salivary glands while setting also the bases of modern geology. Moreover, at the end of the 17th century, the anatomical wax modelling techniques arose and developed in Florence thanks to the work of Gaetano Zumbo (or Zummo), capable of creating some real masterpieces, still very well preserved and collected in the Museum of Natural Sciences "La Specola".

Some interesting observations on the surface features of the liver and their clinical implications

INTRODUCTION

A sound knowledge of the normal and variant liver anatomy is a prerequisite to having a favourable surgical outcome. Knowledge of the commonly-occurring variations assumes even more significance in the era of diagnostic imaging and minimally-invasive surgical approaches. Although the segmental anatomy of the liver has been extensively researched, very few studies have dealt with the surface variations of the liver.

METHODS

90 formalin-fixed livers were utilised for the study. Variations regarding the shapes of the caudate and the quadrate lobes as well as the normal fissures were observed. The presence of the accessory fissures and any other variations on the surface of the livers were noted.

RESULTS

Varied shapes of the caudate and the quadrate lobes were encountered. Notching along the inferior border of the caudate lobe was seen in 18 percent of livers, a vertical fissure was observed in 30 percent, and prominent papillary process was seen in 32 percent. Accessory fissures and grooves were more common in the right lobe. Multiple prominent vertical grooves were observed on the anterosuperior surface of the liver in six percent of livers. Quadrate lobe was absent in four percent, and in two cases, it was found to be deeply buried. Presence of a pons hepatis, bridging the left and the quadrate lobes, was observed in 30 percent of the livers examined.

CONCLUSION

Our study is expected to serve as a guide for proper interpretations of liver images using various imaging modalities. It will also be useful to the operating surgeons to be aware of the frequently-occurring morphological variations on the liver surface.

Improved diagnostics through quantitative ultrasound imaging

Conventional B-mode imaging in ultrasound consists of displaying the log-compressed envelope of the backscattered signal. While clinical ultrasonic B-mode images have good spatial resolution, i.e., better than a millimeter, the contrast resolution of ultrasonic B-mode images is typically low. However, additional information is contained in the ultrasonic backscattered signal, which can be used to create images related to tissue microstructure. Because diagnosis of disease is typically based on histological examination of tissue microstructure, the ability to quantify and describe tissue microstructure through ultrasound may result in improved diagnostic capabilities of ultrasound. Tissue-mimicking phantoms and animal models of breast cancer were used to assess the ability of novel ultrasonic imaging techniques to quantify microstructure. Four parameters were extracted from the ultrasonic backscattered signal and related to the microstructure. The effective scatterer diameter (ESD) and the effective acoustic concentration (EAC) parameters were based on modeling the frequency dependence of the backscatter. The k parameter (which quantifies the periodicity of scatterer locations) and the mu parameter (which estimates the number of scatterers per resolution cell) were based on modeling the statistics of the backscattered envelope. Images constructed with these parameters resulted in an increase in contrast between diseased tissue and normal tissues but at the expense of spatial resolution. Specifically, in simulation, quantitative ultrasound (QUS) increased the contrast-to-noise ratio (CNR) between targets and background by more than 10 times in some cases. Statistically significant differences were observed between three kinds of tumors using the ESD, EAC, and k parameters. QUS imaging was also improved with the addition of coded excitation. A novel coded excitation technique was used that improved the variance of estimates over conventional pulsing methods, e.g- , the variance of ESD estimates were reduced by a factor of up to 10.

A new presentation and exploration of human cerebral vasculature correlated with surface and sectional neuroanatomy

The increasing complexity of human body models enabled by advances in diagnostic imaging, computing, and growing knowledge calls for the development of a new generation of systems for intelligent exploration of these models. Here, we introduce a novel paradigm for the exploration of digital body models illustrating cerebral vasculature. It enables dynamic scene compositing, real-time interaction combined with animation, correlation of 3D models with sectional images, quantification as well as 3D manipulation-independent labeling and knowledge-related meta labeling (with name, diameter, description, variants, and references). This novel exploration is incorporated into a 3D atlas of cerebral vasculature with arteries and veins along with the surrounding surface and sectional neuroanatomy derived from 3.0 Tesla scans. This exploration paradigm is useful in medical education, training, research, and clinical applications. It enables development of new generation systems for rapid and intelligent exploration of complicated digital body models in real time with dynamic scene compositing from highly parcellated 3D models, continuous navigation, and manipulation-independent labeling with multiple features.

[An interactive three-dimensional model of the human body]

Driven by advanced computer technology, it is now possible to show the human anatomy on a computer. On the internet, the Visible Body programme makes it possible to navigate in all directions through the anatomical structures of the human body, using mouse and keyboard. Visible Body is a wonderful tool to give insight in the human structures, body functions and organs.