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Traumatic injuries to the thorax are a common occurrence, and given the disparity in outcomes, injury risk is non-uniformly distributed within the population. Rib cage geometry, in conjunction with well-established biomechanical characteristics, is thought to influence injury tolerance, but quantifiable descriptions of adult rib cage shape as a whole are lacking. Here, we develop an automated pipeline to extract whole rib cage measurements from a large population and produce distributions of these measurements to assess variability in rib cage shape. Ten measurements of whole rib cage shape were collected from 1,719 individuals aged 25–45 years old including angular, linear, areal, and volumetric measures. The resulting pipeline produced measurements with a mean percent difference to manually collected measurements of 1.7% ± 1.6%, and the whole process takes 30 s per scan. Each measurement followed a normal distribution with a maximum absolute skew value of 0.43 and a maximum absolute excess kurtosis value of 0.6. Significant differences were found between the sexes (p < 0.001) in all except angular measures. Multivariate regression revealed that demographic predictors explain 29%–68% of the variance in the data. The angular measurements had the three lowest R2 values and were also the only three to have little correlation with subject stature. Unlike other measures, rib cage height had a negative correlation with BMI. Stature was the dominant demographic factor in predicting rib cage height, coronal area, sagittal area, and volume. Subject weight was the dominant demographic factor for rib cage width, depth, axial area, and angular measurements. Age was minimally important in this cohort of adults from a narrow age range. Individuals of similar height and weight had average rib cage measurements near the regression predictions, but the range of values across all subjects encompassed a large portion of their respective distributions. Our findings characterize the variability in adult rib cage geometry, including the variation within narrow demographic criteria. In future work, these can be integrated into computer aided engineering workflows to assess the influence of whole rib cage shape on the biomechanics of the adult human thorax.

Variability in the topography of the arteries of the upper extremity is associated with fetal development. Determination of individual anatomical variants of the upper extremity blood supply at different stages of ontogeny, especially in human fetuses, is of great practical importance in vascular surgery. Aim of the study. To study the individual anatomical variability of the ulnar and radial arteries in human fetuses of different ages. Material and methods. The study of variants of the topography of the branches of the radial and ulnar arteries, the peculiarities of the formation of the superficial palmar arterial arch was carried out on 46 preparations of the upper extremities of 23 human fetuses 81. 0-375, 0 mm parieto-coccygeal length using macromicroscopic dissection, vascular injection and morphometry without external signs of anatomical abnormalities or congenital malformations of skeletal, fascial-muscular and vascular-nerve structures of the upper extremities. Results and discussion. Our study demonstrated fetal anatomical variability and bilateral asymmetry of the right and left upper extremity arteries in human fetuses. Thus, in a fetus with a PCL of 210.0 mm, the right brachiocephalic artery was found to originate from the right axillary artery. It should be noted that the initial portion of the right brachiocephalic artery passed anteriorly, not posteriorly, to the median nerve, and at the level of the middle third of the anterior shoulder region, the artery occupied a superficial position relative to the median nerve, which is located in the lateral bicuspid groove of the shoulder. The brachiocephalic artery was then directed in an oblique lateral direction to the lateral surface of the forearm. In this fetus, a high origin of the right ulnar artery was found, which originated from the trunk of the brachiocephalic artery in the upper third of the right anterior shoulder region. At the border of the middle and lower thirds of the anterior shoulder region, the ulnar artery crossed the ulnar nerve anteriorly and passed with it in the median biceps groove of the shoulder. 3.0 mm below the beginning of the ulnar artery, the superior circumflex ulnar artery bifurcated from the brachiocephalic artery, and in the lower third of the anterior shoulder region, a common trunk bifurcated from the brachiocephalic artery and bifurcated into the middle and inferior circumflex ulnar arteries. We found arterial anastomoses between the latter and branches of the ulnar artery. The immediate continuation of the right brachiocephalic artery in the palm was the brachiocephalic artery of the thumb. At the level of the base of the proximal phalanx of the thumb, the brachiocephalic artery branched into three palmar finger arteries, which were directed to both edges of the palmar surface of the first finger and the radial edge of the palmar surface of the second finger. The superficial palmar arch was formed by the superficial palmar branch of the brachial radial artery, the terminal ulnar artery, and the anterior interosseous artery. Four common palmar arteries originated from the superficial palmar arch and were directed to the ulnar edge of the palmar surface of the second finger and the palmar surfaces of the adjacent edges of the third through fifth fingers. The left superficial palmar arch had an atypical structure located under the palmar aponeurosis at the level of the middle of the metacarpals and formed by the terminal parts of the ulnar and anterior interosseous arteries. Because the radial artery in this fetus was traced to the distal part of the forearm (to the scaphoid bone), we did not find branches of this artery in the palm area, especially the superficial palmar branch of the radial artery. The ulnar artery was directed caudally to the palmar region, curving slightly in an arc to the radial side of the hand. From the terminal portion of the ulnar artery, three common palmar finger arteries bifurcated, which in turn bifurcated into five palmar finger arteries of their own. The latter supplied the ulnar edge of the third finger and the palmar areas of the fourth and fifth fingers. The radial edge of the third finger and the palmar areas of the II-I fingers were supplied by five separate palmar arteries originating from the terminal portion of the anterior interosseous artery. Anastomoses were found between the palmar arteries, mainly in the middle and terminal phalanges. In the area of the palm, numerous muscular branches bifurcated from the anterior interosseous and ulnar arteries, providing blood supply to the palm muscles. Conclusions. In the majority of the studied fetuses (82.61 %) the superficial palmar arch was closed, in 17.39 % of the observations it was not closed. In 10.5 % of cases, the superficial palmar arch was formed by the trunk of the ulnar artery and the median forearm artery, and in 5.2 % - with the participation of the ulnar and anterior interosseous arteries. The ulnar artery is predominantly involved in the formation of the superficial palmar arch. In a fetus with a PCL of 210.0 mm, the right brachiocephalic artery was found, as well as a high origin of the right ulnar artery from it and an atypical branching of other branches. In particular, the superficial palmar arch was formed by the superficial palmar branch of the brachial radial artery, the terminal ulnar artery, and the anterior interosseous artery, while the left superficial palmar arch was formed by the terminal ulnar and anterior interosseous arteries. [ABSTRACT FROM AUTHOR]

Abstract Introduction - Le ligament talo-fibulaire antérieur représente le faisceau antérieurdu complexe ligamentaire latéral de la cheville. Etant le moins résistant, il est lepremier touché en cas d’entorse latérale de la cheville. Notre travail a pour but demettre en évidence la grande variabilité de ce ligament.Matériels et méthodes - A partir de la dissection de 24 chevilles fraîches et embauméesau formaldéhyde, le nombre de faisceaux, les dimensions au point neutre etaprès mise en tension, les rapports avec les structures de voisinage, ainsi que lespoints d’insertions du LTFA ,ont été étudiés.Résultats - Le ligament talo-fibulaire antérieur était bi-fasciculaire dans 66,7%des cas et mono-fasciculaire dans 33,3% des cas. Sa longueur moyenne en positionneutre était de 20,52 ± 2,35 mm, et sa largeur de 7,10 ± 1,02 mm. En flexionplantaire, la longueur était de 20,9 ± 0,05 mm, et de 21,03 ± 0,07 mm en inversionforcée. La distance entre son insertion talaire et le sommet du processus latéralétait de 16,4 mm ±2 mm.Conclusion - Les connaissances macroscopiques et morphométriques de ce ligament,peuvent fournir une base pour comprendre le mécanisme lésionnel, et permettreainsi une meilleure prise en charge des entorses latérales de la cheville. Abstract Introduction - The anterior talofibular ligament represents the anterior bundle of the lateral complex of the ankle. Being the least resistant, it is the first touched in case of lateral sprain of the ankle. Our work aims to highlight the great variability of this ligament. Material and methods - From the dissection of 24 fresh and formaldehyde embalmed ankles, the number of beams, the dimensions at the neutral point and after tensio-ning, the relations with the neighborhood structures, as well as the insertion points of the LTFA have been studied. Results - The anterior talofibular ligament was formed in 66, 7% of the cases of two bundles and in 33, 3% of the cases it was monofascicular. Its average length in neutral position was 20, 52 ± 2, 35 mm, its width was 7, 10 ± 1, 02 mm. In plantar flexion, the length was 20, 9 ± 0, 05 mm, and in forced inversion, it was 21, 03 ± 0, 07 mm. The distance between his talar insertion and the vertex of the lateral process was 16, 4 mm ± 2 mm. Conclusion - The macroscopic and morphometric knowledge of this ligament can provide a basis for understanding the mechanism of injury, and thus allow better management of lateral ankle sprains.

Variability in the topography of the arteries of the upper extremity is associated with fetal development. Determination of individual anatomical variants of the upper extremity blood supply at diff erent stages of ontogeny, especially in human fetuses, is of great practical importance in vascular surgery. Aim of the study. To study the individual anatomical variability of the ulnar and radial arteries in human fetuses of diff erent ages. Material and methods. The study of variants of the topography of the branches of the radial and ulnar arteries, the peculiarities of the formation of the superfi cial palmar arterial arch was carried out on 46 preparations of the upper extremities of 23 human fetuses 81. 0-375, 0 mm parieto- coccygeal length using macromicroscopic dissection, vascular injection and morphometry without external signs of anatomical abnormalities or congenital malformations of skeletal, fascial- muscular and vascular- nerve structures of the upper extremities. Results and discussion. Our study demonstrated fetal anatomical variability and bilateral asymmetry of the right and left upper extremity arteries in human fetuses. Thus, in a fetus with a PCL of 210.0 mm, the right brachiocephalic artery was found to originate from the right axillary artery. It should be noted that the initial portion of the right brachiocephalic artery passed anteriorly, not posteriorly, to the median nerve, and at the level of the middle third of the anterior shoulder region, the artery occupied a superfi cial position relative to the median nerve, which is located in the lateral bicuspid groove of the shoulder. The brachiocephalic artery was then directed in an oblique lateral direction to the lateral surface of the forearm. In this fetus, a high origin of the right ulnar artery was found, which originated from the trunk of the brachiocephalic artery in the upper third of the right anterior shoulder region. At the border of the middle and lower thirds of the anterior shoulder region, the ulnar artery crossed the ulnar nerve anteriorly and passed with it in the median biceps groove of the shoulder. 3.0 mm below the beginning of the ulnar artery, the superior circumfl ex ulnar artery bifurcated from the brachiocephalic artery, and in the lower third of the anterior shoulder region, a common trunk bifurcated from the brachiocephalic artery and bifurcated into the middle and inferior circumfl ex ulnar arteries. We found arterial anastomoses between the latter and branches of the ulnar artery. The immediate continuation of the right brachiocephalic artery in the palm was the brachiocephalic artery of the thumb. At the level of the base of the proximal phalanx of the thumb, the brachiocephalic artery branched into three palmar fi nger arteries, which were directed to both edges of the palmar surface of the fi rst fi nger and the radial edge of the palmar surface of the second fi nger. The superfi cial palmar arch was formed by the superfi cial palmar branch of the brachial radial artery, the terminal ulnar artery, and the anterior interosseous artery. Four common palmar arteries originated from the superfi cial palmar arch and were directed to the ulnar edge of the palmar surface of the second fi nger and the palmar surfaces of the adjacent edges of the third through fi fth fi ngers. The left superfi cial palmar arch had an atypical structure located under the palmar aponeurosis at the level of the middle of the metacarpals and formed by the terminal parts of the ulnar and anterior interosseous arteries. Because the radial artery in this fetus was traced to the distal part of the forearm (to the scaphoid bone), we did not fi nd branches of this artery in the palm area, especially the superfi cial palmar branch of the radial artery. The ulnar artery was directed caudally to the palmar region, curving slightly in an arc to the radial side of the hand. From the terminal portion of the ulnar artery, three common palmar fi nger arteries bifurcated, which in turn bifurcated into fi ve palmar fi nger arteries of their own. The latter supplied the ulnar edge of the third fi nger and the palmar areas of the fourth and fi fth fi ngers. The radial edge of the third fi nger and the palmar areas of the II-I fi ngers were supplied by fi ve separate palmar arteries originating from the terminal portion of the anterior interosseous artery. Anastomoses were found between the palmar arteries, mainly in the middle and terminal phalanges. In the area of the palm, numerous muscular branches bifurcated from the anterior interosseous and ulnar arteries, providing blood supply to the palm muscles. Conclusions. In the majority of the studied fetuses (82.61 %) the superfi cial palmar arch was closed, in 17.39 % of the observations it was not closed. In 10.5 % of cases, the superfi cial palmar arch was formed by the trunk of the ulnar artery and the median forearm artery, and in 5.2 % – with the participation of the ulnar and anterior interosseous arteries. The ulnar artery is predominantly involved in the formation of the superfi cial palmar arch. In a fetus with a PCL of 210.0 mm, the right brachiocephalic artery was found, as well as a high origin of the right ulnar artery from it and an atypical branching of other branches. In particular, the superfi cial palmar arch was formed by the superfi cial palmar branch of the brachial radial artery, the terminal ulnar artery, and the anterior interosseous artery, while the left superfi cial palmar arch was formed by the terminal ulnar and anterior interosseous arteries.

IntroductionConductive hearing loss describes an insufficient sound transfer of the middle ear, often caused by defects or absence of the ossicles. Depending on the specific middle ear dimensions and the kind of defect, surgeons can choose from a variety of passive implants to reconstruct the middle ear and hence restore sound transmission. However, the latter is only achieved if the optimal implant size is available and selected for each individual patient.MethodsAnatomical dimensions relevant for middle ear reconstruction were assessed within high-resolution clinical imaging data of 50 patients (100 ears). The ranges of these dimensions were then compared to implant types and sizes available from different manufacturers.ResultsIn general, total and partial prostheses seem to cover the whole range of anatomical variations. A lack of stapesplasty implants was found for particularly small anatomies. Various implant lengths of all types far exceed dimensions necessary for successful restoration of sound transmission. In some cases, implant lengths are not clearly specified by the manufacturer. Tympanic membrane and stapes axis were not in line for any of the investigated middle ears.ConclusionClear specifications of implant lengths are crucial to allow for successful hearing restoration, and clinics often need to have more than one implant type to cover the entire range of anatomical variations they may encounter. There appears to be an unmet clinical need for smaller stapesplasty implants. Devices which allow for an angular adjustment between distal and proximal end appear to mimic the orientation of the ossicles more naturally.

Introduction. Elucidation of the sources of human orbital bones, clarification of the sequence of their ossification will allow to create a morphological basis for effective interpretation of the data of fetal condition monitoring, will contribute to early diagnosis of variants of the structure and possible malformations of the head, organ of vision and related structures. The aim of the study. The aim of this work was to find out the sources of origin, the chronology of ossification, the characteristics of age-related topographic and anatomical changes in the bones of the orbit. Material and methods. 18 series of histological sections of samples of human embryos and pre-fetuses at the age of 4-12 weeks of intrauterine development (4,0-80,0 mm parietal-coccygeal length) and samples of 12 fetuses at the age of 4-9 months of intrauterine development (130,0-450. 0 mm parietal-calcaneal length) using a complex of morphological research methods (anthropometry, morphometry, preparation of histological sections, dissection, three-dimensional reconstruction of series of histological sections and computer tomography, statistical analysis). The study was conducted in accordance with the main provisions of the European Union Convention on Human Rights and Biomedicine (1997), as well as the Helsinki Declaration on Ethical Principles of Medical Research Involving Human Subjects (1964-2008), EU Directive No. 609 (1986), Order of the Ministry of Health of Ukraine dated 23.09.2009 No. 690. The work was carried out within the framework of the initiative research work of the Department of Histology, Cytology and Embryology of the Bukovinian State Medical University «Structural and functional peculiarities of tissues and organs in ontogenesis, regularities of variant, constitutional, sex and age-related and comparative human morphology». State registration number: 0121U110121. Deadlines: 01.2021-12.2025. The Results. The first signs of the appearance of ossification centers around the main nervous and visceral contents of the rudiment of the orbit are determined in 6-week-old embryos in the form of seven cartilaginous bone models, and the first centers of ossification among the rudiments of bones participating in the formation of the orbit are found in the rudiment of the maxilla. In the 6th month of intrauterine development, the processes of ossification of the frontal, sphenoid, ethmoid and maxillary bones begin. At the end of the 8th month of intrauterine development, due to the ossification processes of the lesser wing of the sphenoid and frontal bones, the orbit acquires features of a definitive structure. From the beginning of the fetal period of human ontogenesis, ossification of the structures of the sphenoid bone continues, which leads to morphological transformations of the orbit in 5-month fetuses - it is separated from the sphenopalatine and infratemporal fossa by a bone layer, the optic canal is formed, and in 6-month fetuses processes of ossification of the frontal, sphenoid, ethmoid and maxillary bones, and Müller's orbital muscle changes its structure into a fibrous one. The analysis of the age-related dynamics of the morphometric parameters of the orbit during the fetal period of intrauterine development made it possible to establish the peculiarities of changes in its diameter, circumference and area, which are expressed by mathematical functions: diameter of the orbit, mm = -0. 2285+0.4704*x; circumference of the orbit, mm = -0.2924+1.4595*x; area of the orbit, mm2 = -87.8597+8.0387*x, where x is the age of the human fetus in weeks. Conclusion. The critical periods of the development of the orbit are the 6th month of prenatal ontogenesis, during which there is an uneven growth rate of the horizontal size of the orbit in relation to the vertical one, and its shape returns to the mesoconchal, which was previously observed in fetuses, as well as the 8th month, during which the growth of all parameters of the orbit slows down due to intensive processes of organogenesis of its visceral structures. [ABSTRACT FROM AUTHOR]

Statistical Shape Models (SSMs) are widely used in orthopedics to extract the main shape features from bone regions (e.g., femur). This study aims to develop an SSM of the femoral medullary canal, investigate its anatomical variability, and assess variations depending on canal length. The canals were isolated from 72 CT femur scans, through a threshold-based segmentation. A region of interest (ROI) was selected; sixteen segments were extracted from the ROI, ranging from 25% of the full length down to the most distal segment. An SSM was developed to identify the main modes of variation for each segment. The number of Principal Components (PCs) needed to explain at least 90% of the shape variance were three/four based on the length of the canal segment. The study examined the relationship between the identified PCs and geometric parameters like length, radius of curvature, ellipticity, mean diameter, and conicity, reporting range and percentage variation of these parameters for each segment. The SSMs provide insights into the anatomical variability of the femoral canal, emphasizing the importance of considering different segments to capture shape variations at various canal length. These findings can contribute for the design of personalized orthopedic implants involving the distal femur.

Introduction The wide range of anatomical variability of the structures of the middle cranial fossa (MCF) and the lack of reliable surgical landmarks contribute to a high level of complications in the surgical treatment of vestibular schwannomas. We hypothesized that the cranial phenotype influences the shape of the MCF, the orientation of the pyramid of the temporal bone, and the relative topography of the internal acoustic canal (IAC). Methods The skull base structures were studied on 54 embalmed cadavers and 60 magnetic resonance images of the head and neck by photo modeling, dissection, and three-dimensional analysis techniques. By the value of the cranial index, all specimens were subdivided into dolichocephalic, mesocephalic, and brachycephalic groups for comparison of variables. Results The length of the superior border of the temporal pyramid (SB), the apex to squama distance, and the width of the MCF all peaked in the brachycephalic group. The value of the angle between the SB and the axis of the acoustic canal varied from 33 to 58 degrees; it peaked in the dolichocephalic group and showed its smaller value in the brachycephalic one. The pyramid to squama angle had reversed distribution and dominated in the brachycephalic group. Conclusion The cranial phenotype influences the shape of the MCF, temporal pyramid, and IAC. Presented in this article data help specialists operating on the vestibular schwannoma to localize the IAC based on the individual shape of a skull. [ABSTRACT FROM AUTHOR]

Summary. Patients with scalp defects require a comprehensive examination to save lives and reduce the consequences of trauma. Plastic surgeons must take into account the anatomical, functional and cosmetic characteristics of the scalp. The aim of the study – to find out the topographical and anatomical relationships of the superficial temporal artery and its branches in human fetuses of 4–8 months. Materials and Methods. The research was carried out on the preparations of 22 human fetuses of 81.0–310.0 mm parietal-coccygeal length (PCL) without external signs of anatomical deviations or anomalies of the development of bone, fascial-muscular and vascular-nervous structures of the head using macromicroscopic dissection, injection of vessels and morphometry. Results. The classic variant of the topography of the superficial temporal artery was found in most of the examined fetuses. In some of them, variants of branching of the superficial temporal artery, variability of the number of branches, and various anastomoses have been established. A variant of branching of the left superficial temporal artery was observed in a human fetus with a 195.0 mm PCL. An anastomosis between the right and left supraorbital arteries and the frontal branches of the right and left superficial temporal arteries was found in a 230.0 mm PCL fetus. In a human fetus with a 180.0 mm PCL, a blood supply variant of the left posterolateral part of the head was found. The left occipital artery provided blood supply not only to the occipital but also to the parietal areas. In another human fetus with a 170.0 mm PCL, a doubling of the right occipital artery was detected. Conclusions. In the fetal period of human ontogenesis, the anatomical variability of the arteries supplying blood to the skin and surface structures of the head has been established. Variants of the topography of the superficial temporal artery, the supraorbital artery, and the occipital artery were revealed, manifested by the variability of the shape, the number of branches, and the formation of arterial anastomoses. The various topographic variants of the branches of the superficial temporal artery, supraorbital and occipital arteries described in human fetuses will help plastic surgeons to choose individually the most rational method of surgical intervention to repair head defects

Introduction. Performing surgical manipulations and interventions on neurovascular bundles located in the anterior brachial region of human fetuses and newborns requires comprehensive knowledge of their topographical and anatomical features. The objective of the study was to establish the fetal topography peculiarities of both nerves and vessels in the anterior brachial muscle region. Materials and methods. The study was carried out on 32 human fetuses of 4-8 months with 81.0-310.0 mm crown-rump length (CRL) using macro microscopic dissection, vascular injections and morphometry. Results. We describe the main and additional sources of muscle blood supply and innervation of the anterior brachial region in human fetuses. Two to 4 branches of the musculocutaneous nerve take part in the innervation of both coracobrachialis and brachialis muscles, as well as the biceps brachii muscle. Some fetuses possess additional sources of innervation: for the coracobrachialis muscle there is a branch of the lateral bundle of the brachial plexus, the biceps brachii muscle has median nerve and for the brachialis muscle there is radial nerve. The largest number of arterial and nerve branches goes to the proximal and middle parts of the coracobrachialis and brachialis muscles, as well as the biceps brachii muscle. Conclusions. The established neurovascular correlations and features of the fetal anatomy of the anterior brachial muscle region determine the presence of relatively favourable conditions for cutting muscle flaps that are well innervated and supplied with blood.

Functional near-infrared spectroscopy (fNIRS) is an important non-invasive technique used to monitor cortical activity. However, a varying sensitivity of surface channels vs. cortical structures may suggest integrating the fNIRS with the subject-specific anatomy (SSA) obtained from routine MRI. Actual processing tools permit the computation of the SSA forward problem (i.e., cortex to channel sensitivity) and next, a regularized solution of the inverse problem to map the fNIRS signals onto the cortex. The focus of this study is on the analysis of the forward problem to quantify the effect of inter-subject variability. Thirteen young adults (six males, seven females, age 29.3 ± 4.3) underwent both an MRI scan and a motor grasping task with a continuous wave fNIRS system of 102 measurement channels with optodes placed according to a 10/5 system. The fNIRS sensitivity profile was estimated using Monte Carlo simulations on each SSA and on three major atlases (i.e., Colin27, ICBM152 and FSAverage) for comparison. In each SSA, the average sensitivity curves were obtained by aligning the 102 channels and segmenting them by depth quartiles. The first quartile (depth < 11.8 (0.7) mm, median (IQR)) covered 0.391 (0.087)% of the total sensitivity profile, while the second one (depth < 13.6 (0.7) mm) covered 0.292 (0.009)%, hence indicating that about 70% of the signal was from the gyri. The sensitivity bell-shape was broad in the source–detector direction (20.953 (5.379) mm FWHM, first depth quartile) and steeper in the transversal one (6.082 (2.086) mm). The sensitivity of channels vs. different cortical areas based on SSA were analyzed finding high dispersions among subjects and large differences with atlas-based evaluations. Moreover, the inverse cortical mapping for the grasping task showed differences between SSA and atlas based solutions. In conclusion, integration with MRI SSA can significantly improve fNIRS interpretation. [ABSTRACT FROM AUTHOR]

Commercial autosegmentation has entered clinical use, however real-world performance may suffer in certain cases. We aimed to assess the influence of anatomic variants on performance. We identified 112 prostate cancer patients with anatomic variations (edge cases). Pelvic anatomy was autosegmented using three commercial tools. To evaluate performance, Dice similarity coefficients, and mean surface and 95% Hausdorff distances were calculated versus clinician-delineated references. Deep learning autosegmentation outperformed atlas-based and model-based methods. However, edge case performance was lower versus the normal cohort (0.12 mean DSC reduction). Anatomic variation presents challenges to commercial autosegmentation.

Traumatic injuries to the thorax are a common occurrence, and given the disparity in outcomes, injury risk is non-uniformly distributed within the population. Rib cage geometry, in conjunction with well-established biomechanical characteristics, is thought to influence injury tolerance, but quantifiable descriptions of adult rib cage shape as a whole are lacking. Here, we develop an automated pipeline to extract whole rib cage measurements from a large population and produce distributions of these measurements to assess variability in rib cage shape. Ten measurements of whole rib cage shape were collected from 1,719 individuals aged 25-45 years old including angular, linear, areal, and volumetric measures. The resulting pipeline produced measurements with a mean percent difference to manually collected measurements of 1.7% ± 1.6%, and the whole process takes 30 s per scan. Each measurement followed a normal distribution with a maximum absolute skew value of 0.43 and a maximum absolute excess kurtosis value of 0.6. Significant differences were found between the sexes ( p < 0.001) in all except angular measures. Multivariate regression revealed that demographic predictors explain 29%-68% of the variance in the data. The angular measurements had the three lowest R 2 values and were also the only three to have little correlation with subject stature. Unlike other measures, rib cage height had a negative correlation with BMI. Stature was the dominant demographic factor in predicting rib cage height, coronal area, sagittal area, and volume. Subject weight was the dominant demographic factor for rib cage width, depth, axial area, and angular measurements. Age was minimally important in this cohort of adults from a narrow age range. Individuals of similar height and weight had average rib cage measurements near the regression predictions, but the range of values across all subjects encompassed a large portion of their respective distributions. Our findings characterize the variability in adult rib cage geometry, including the variation within narrow demographic criteria. In future work, these can be integrated into computer aided engineering workflows to assess the influence of whole rib cage shape on the biomechanics of the adult human thorax., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Robinson, Zheng, von Kleeck, Tan and Gayzik.)

Evaluation of the regional intranasal delivery of locally acting drugs in children is challenging. Anatomical nasal airway replicas potentially can provide a robust pre-clinical tool to test the performance of devices and formulations. However, there is often a challenge in identifying the nasal geometries that can reasonably be indicative of in vivo regional mass distribution of administered drug. This in vitro study was designed to investigate the regional intranasal drug delivery in 20 children, 2–11 years old (50% 2–6 years old and 50% female), using two commercially available suspension nasal spray products with different nozzle designs, plume characteristics, and active pharmaceutical ingredients. High-resolution computed tomography scans of the sinonasal region of pediatric human subjects with healthy nasal airways, reviewed and scored by a head and neck surgeon, were used to develop 20 three-dimensional (3D) replicas of the nasal airways. The 3D replicas were segmented into the two regions: anterior and posterior to the internal nasal valve (INV). They were then rapid prototyped in high clarity rigid plastic (Accura ClearVue). Each side of the septum of the 20 subjects was examined separately, resulting in 40 singular nasal cavities. A nozzle-specific spray tip holder was designed for each case to ensure consistent administration (insertion length, sagittal angle, and coronal angle) in all replicates. The wide range of posterior drug delivery observed in the forty geometries indicated significant intersubject variability in pediatric intranasal drug delivery. Three nasal geometries representing low, medium, and high levels of drug delivery to the target region, posterior to the INV, were chosen from the 40 nasal cavities. Our vision is that these three nasal geometries can potentially be beneficial in determining whether performance differences between test and reference nasal spray products are present that may affect their bioequivalence in children. They also may be useful when applied in parallel with similar adult nasal geometries, previously developed following a similar procedure, to provide additional insights into pediatric nasal drug delivery with innovator products in children in lieu of extending clinical studies to include pediatric subjects. • In vitro intersubject variability in pediatric drug delivery with nasal sprays is significant. • Three representative pediatric models were identified as candidates for evaluating nasal sprays. • Intranasal drug delivery in children may be more consistent and efficient than in adults. [ABSTRACT FROM AUTHOR]

Objectives: The anatomical features of the atlanto‐occipital joint can be potentially useful in re‐associating or excluding crania to atlases in commingled remains. This study investigated whether linear measurements and the 3‐dimensional (3D) surface of occipital condyles and articular facets of atlases can represent valid insights for this purpose. Methods: The variations among eight corresponding linear distances were analyzed in a sample of 150 individuals through six supervised machine learning techniques attempting to develop classifiers able to identify elements belonging to the same individual. Furthermore, a 3D analysis was conducted on the articular surfaces through superimpositions of 3D models of corresponding and non‐corresponding crania and atlases obtained by using respectively stereophotogrammetry and laser scanning. This analysis investigated differences in terms of point‐to‐point distances (Root Mean Square, RMS) of superimposed 3D surfaces. Results: None of the six machine learning techniques were able to correctly detect a satisfying percentage of correspondent pairs in the overall sample by using the linear variables. The 3D analysis of the articular surfaces found RMS values over 0.53 mm only for superimposed non‐corresponding surfaces, which sets a threshold value to identify 32% of incorrect pairs. Discussion: The re‐association of cranium to atlas proved to be challenging and hardly possible when considering only metric variables. However, the 3D geometry of the articular surfaces represents a valid variable for this purpose and 3D analyses pave the way for an initial exclusion of incorrect re‐associations, thus should not be considered as a re‐association method per se, but as an exclusionary screening technique. [ABSTRACT FROM AUTHOR]

Abstract Introduction - The anterior talofibular ligament represents the anterior bundle of the lateral complex of the ankle. Being the least resistant, it is the first touched in case of lateral sprain of the ankle. Our work aims to highlight the great variability of this ligament. Material and methods - From the dissection of 24 fresh and formaldehyde embalmed ankles, the number of beams, the dimensions at the neutral point and after tensioning, the relations with the neighborhood structures, as well as the insertion points of the LTFA have been studied. Results - The anterior talofibular ligament was formed in 66, 7% of the cases of two bundles and in 33, 3% of the cases it was monofascicular. Its average length in neutral position was 20, 52 ± 2, 35 mm, its width was 7, 10 ± 1, 02 mm. In plantar flexion, the length was 20, 9 ± 0, 05 mm, and in forced inversion, it was 21, 03 ± 0, 07 mm. The distance between his talar insertion and the vertex of the lateral process was 16, 4 mm ± 2 mm. Conclusion - The macroscopic and morphometric knowledge of this ligament can provide a basis for understanding the mechanism of injury, and thus allow better management of lateral ankle sprains.

Purpose: The Sciatic Nerve Division (SND) into the Common Peroneal Nerve and Tibial Nerve presents a great anatomical variability in its location in the thigh, but the influence of age on it has not been fully addressed. Methods: Anatomical distances from greater trochanter to SND and from SND to popliteal crease were obtained by ultrasound examination in 60 children (age 1–12 years) and 60 adult patients (age 13–80 years) who were scheduled for programmed surgery. A sciatic nerve/thigh coefficient [Greater Trochanter-SND/(Greater Trochanter-popliteal crease)*100] and its coefficient of variation (standard deviation/mean*100) were calculated. Greater Trochanter-SND and SND-Popliteal crease were also correlated with patients´ age, weight and height. Results: There were statistically significant differences between children and adult in Greater Trochanter-SND (20.5 ± 5,5 vs 33.9 ± 2.7; p < 0.0001) and in SND-Popliteal (4.9 ± 2.1 vs 6.7 ± 1.6; p < 0.0001) distances measured in cm. There were also statistically significant differences between children and adults in Sciatic nerve/thigh coefficient (80% vs 83%; p < 0.0001) and its index of variation (8.1% vs 4.8%; p < 0.0001). In children, both Greater Trochanter-SND and SND-Popliteal distances were strongly correlated with age (r2 = 0.868 and r2 = 0.261, respectively; p < 0.0001), weight (r2 = 0.778 and r2 = 0.278, respectively; p < 0.0001) and height (r2 = 0.898 and r2 = 0.225, respectively; p < 0.0001). However, in older patients, only Greater Trochanter-SND distance was statistically correlated with height (r2 = 0.372; p = 0.0001) and not with age or weight; SND-Popliteal distance did not show statistically relevant correlation, either. Conclusion: Children presented even more anatomical variability than adults in sciatic nerve division due to the growth of both the proximal and distal nervous structures of the thigh before 12 years of age. [ABSTRACT FROM AUTHOR]

The study of age and individual anatomical variability of vagus nerves and their branches in different age periods of human ontogenesis causes interest among both morphologists and doctors of different specialties. The aim of the study. To find out the topography of the cervical and thoracic divisions of the vagus nerves in human fetuses aged from 4th to 10th gestational months. Materials and methods. The research was conducted on 75 preparations of human fetuses ranging from 81.0 to375.0 mm in parietal-coccygeal length (PCL) using methods of macro-microscopic dissection and morphometry. Results. In human fetuses, the left vagus nerve is placed anteriorly to the left subclavian artery, then on the lateral surface of the Botallo’s arterial duct and the aortic arch. In the neck region, the superior cardiac branch departs from the left vagus nerve and goes to the anterior surface of the left common carotid artery. In the inferior part of the left common carotid artery, the superior cardiac branch gives off two branches: the middle one reaches the aortic arch wall, and the lateral one runs along the anterior surface of the left common carotid artery. The left recurrent laryngeal nerve departs from the left vagus nerve at the level of the inferior border of the aortic arch. The right vagus nerve passes from the right subclavian artery anteriorly and gives rise to the right recurrent laryngeal nerve, which continues inferiorly and posteriorly around the subclavian artery. The superior cardiac branch originates from the right vagus nerve at the level of the inferior border of the thyroid gland. The inferior cardiac branch departs inferiorly and medially from the right laryngeal nerve and is located on the right anterolateral surface of the trachea. Conclusions. During the fetal period of human ontogenesis, age and individual anatomical variations of the branches of the cervical and thoracic vagus nerves is observed, which is manifested by the variability of the structure, asymmetry of the topography of the recurrent laryngeal nerves, bronchial, esophageal and cardiac branches. The left recurrent laryngeal nerve departs from the left vagus nerve at the level of the inferior border of the aortic arch, the right recurrent laryngeal nerve departs from the right vagus nerve at the level of the right subclavian artery. The esophageal nervous plexus is formed by esophageal branches of the vagus nerves, which then forms mainly the posterior vagal trunk. The anterior vagal trunk is a direct continuation of the left vagus nerve branches. The innervation of the aortic arch involves the common cardiac trunk, which is formed by the superior cardiac branch and the superior cardiac nerve and also anastomoses both with vagus nerve and with recurrent laryngeal nerves.

Introduction. The accumulated factual material about the topography of the great saphenous vein is extremely contradictory. Therefore, an individual approach is necessary to study the age-related anatomical variability of the large saphenous vein in human fetuses. The objective of the study was to determine the peculiarities of the saphenous vein topography in human fetuses of 4-10 months. Materials and methods. Studies of the variant anatomy of the great saphenous vein (GSV) were carried out on specimens of the lower limbs of 80 human fetuses of 81.0-375.0 mm parietal-coccygeal length using macro-microscopic dissection, vascular injection, surface staining of prepared vessels and nerves, radiography and morphometry. Results. GSV is a continuation of the medial marginal vein, which is directed upwards in the subcutaneous tissue along the anterior edge of the inner ankle in the studied human fetuses. On the lower leg, the GSV runs along the medial edge of the tibia and receives superficial veins from the anterior medial surface of the lower leg. The GSV bends around the back of the medial epicondyle of the femur in the knee area, is located outside the sartorial muscle, and passes to the anteromedial surface of the thigh. The GSV returns inward through the perforated fascia. In the saphenous opening area, it bends around the lower corner of the falciform margin of the saphenous opening, and it flows into the femoral vein (FV) from the anteromedial side. The anterior accessory saphenous vein flows into the femoral part of the GSV in 45% of cases. The posterior accessory saphenous vein is formed from the saphenous veins of the medial and posterior surfaces of the thigh. Conclusions. The anatomical variability of the great saphenous vein has been determined in human fetuses. The anterior accessory saphenous vein was detected in 71.3% of the studied fetuses, while the posterior accessory saphenous vein was found in 38.1% of cases. The great saphenous vein is characterized by the predominance of the transitional vein type (55.6% of cases) over the main (33.8% of cases) and loose (10.6%o cases) ones. The main type prevails over the loose type in the ratio of 3.2:1. The coincidence of the type of formation of a great saphenous vein on the right and left lower extremities was observed in 61.3% of fetuses. Significant gender differences in the typology of the great saphenous vein in human fetuses were not found.

Functional near-infrared spectroscopy (fNIRS) is an important non-invasive technique used to monitor cortical activity. However, a varying sensitivity of surface channels vs. cortical structures may suggest integrating the fNIRS with the subject-specific anatomy (SSA) obtained from routine MRI. Actual processing tools permit the computation of the SSA forward problem (i.e., cortex to channel sensitivity) and next, a regularized solution of the inverse problem to map the fNIRS signals onto the cortex. The focus of this study is on the analysis of the forward problem to quantify the effect of inter-subject variability. Thirteen young adults (six males, seven females, age 29.3 ± 4.3) underwent both an MRI scan and a motor grasping task with a continuous wave fNIRS system of 102 measurement channels with optodes placed according to a 10/5 system. The fNIRS sensitivity profile was estimated using Monte Carlo simulations on each SSA and on three major atlases (i.e., Colin27, ICBM152 and FSAverage) for comparison. In each SSA, the average sensitivity curves were obtained by aligning the 102 channels and segmenting them by depth quartiles. The first quartile (depth < 11.8 (0.7) mm, median (IQR)) covered 0.391 (0.087)% of the total sensitivity profile, while the second one (depth < 13.6 (0.7) mm) covered 0.292 (0.009)%, hence indicating that about 70% of the signal was from the gyri. The sensitivity bell-shape was broad in the source–detector direction (20.953 (5.379) mm FWHM, first depth quartile) and steeper in the transversal one (6.082 (2.086) mm). The sensitivity of channels vs. different cortical areas based on SSA were analyzed finding high dispersions among subjects and large differences with atlas-based evaluations. Moreover, the inverse cortical mapping for the grasping task showed differences between SSA and atlas based solutions. In conclusion, integration with MRI SSA can significantly improve fNIRS interpretation.

Background: The integration of advanced imaging technologies, such as Cone Beam Computed Tomography (CBCT), has transformed the rehabilitation treatment for military maxillofacial trauma, enhancing care delivery. Despite these advancements, the field lacks a comprehensive anatomical analysis of endosteal, zygomatic, and pterygoid implants, a gap that limits clinical decision-making efficacy. Addressing this research void could significantly improve the selection of implants, tailored to the unique challenges of military-induced injuries. This study underscores the necessity of embracing imaging-driven, personalized anatomical insights, particularly for those afflicted by maxillofacial trauma. Objective: This research aims to leverage the capabilities of CBCT imaging to optimize rehabilitation for military personnel by focusing on anatomically informed clinical decisionmaking for maxillofacial injuries. Through a detailed comparative analysis of different implant types, facilitated by CBCT, the study seeks to guide toward refined clinical practices that accommodate the anatomical uniqueness of each patient, thereby enhancing care in military trauma scenarios. Material and methods: Our analysis involved 50 anonymized CBCT scans, equivalent to 100 hemimaxillae, to study the impact of maxillary morphological variations on implant placement. Advanced software applications such as Planmeca Romexis Viewer (3.5.0.R), Horos for macOS (Horos Project), and Blue Sky Plan 4 were utilized for precise measurements, comprehensive 3D model assessments, and simulations of implant placements. Measurements focused on the height and width of the alveolar process across three main areas: the anterior (premaxilla), middle (at the zygomaticoalveolar crest), and posterior (tuberosity of the maxilla and pterygoid process). Results : Analysis of the CBCT scans revealed significant variability in the dimensions of the maxillary alveolar process, particularly in the anterior region with widths ranging from 2.7 to 11.65 mm and heights from 6.4 to 27.6 mm. The posterior region also showed significant variability, posing challenges for implant placement. Of note, 21 out of 100 hemimaxillae were unsuitable for zygomatic implants ... due to extensive maxillary resorption and 2 due to highly pneumatized zygomatic bones. Additionally, 9 hemimaxillae were unsuitable for pterygoid implants due to significant resorption. Remarkably, one patient was ineligible for both zygomatic and pterygoid implants, highlighting the complexity of selecting appropriate implants in patients with severe conditions. Conclusions: CBCT utilization for pre-surgical planning is indispensable in the anatomically tailored evaluation of patients, especially following maxillofacial combat trauma which can dramatically alter anatomical landscapes. This precise anatomical assessment is crucial for improving clinical decision-making and outcomes, highlighting the paramount importance of individualized imaging in the strategic planning of implant-based reconstructions for personalized patient care. [ABSTRACT FROM AUTHOR]

Background: The perforating arteries in the dorsolateral zone of the midbrain play a crucial role in the functions of the brain stem. Their damage due to herniation, pathological lesions, or surgery, favored by the narrow tentorial incisura, can lead to hemorrhages or ischemia and subsequently to severe consequences for the patient.Objective: In literature, not much attention has been directed to the perforating arteries in the lemniscus; in fact, no reports on the perforators of this anatomical region are available. The present study aims to a detailed analysis of the microanatomy and the clinical implications of these perforators, in relation to the parent vessels. We focused on the small vessels that penetrate the midbrain's dorsolateral surface, known as lemniscal trigone, to understand better their microanatomy and their functional importance in the clinical practice during the microsurgical approach to this area.Methods: Eighty-seven alcohol-fixed cadaveric hemispheres (44 brains) without any pathological lesions provided the material for studying the perforating vessels and their origin around the dorsolateral midbrain using an operating microscope (OPMI 1 FC, Zeiss). Measurements of the perforators' distances, in relation to the parent vessels, were taken using a digital caliper.Results: An origin from the SCA could be found in 70.11% (61) and from the PCA in 27.58% (24) of the hemispheres. In one hemisphere, an origin from the posterior choroidal artery was found (4.54%). No perforating branches were discovered in 8.04% of specimens (7).Conclusion: The perforating arteries of the lemniscal trigone stem not only from the superior cerebellar artery (SCA), as described in the few studies available in literature, but also from the posterior cerebral artery (PCA). Therefore, special attention should be paid during surgery to spare those vessels and associated perforators. A comprehensive understanding of the lemniscal trigone's perforating arteries is vital to avoid infarction of the brainstem when treating midbrain tumors or vascular malformations.

Background: The perforating arteries in the dorsolateral zone of the midbrain play a crucial role in the functions of the brain stem. Their damage due to herniation, pathological lesions, or surgery, favored by the narrow tentorial incisura, can lead to hemorrhages or ischemia and subsequently to severe consequences for the patient. Objective: In literature, not much attention has been directed to the perforating arteries in the lemniscus; in fact, no reports on the perforators of this anatomical region are available. The present study aims to a detailed analysis of the microanatomy and the clinical implications of these perforators, in relation to the parent vessels. We focused on the small vessels that penetrate the midbrain's dorsolateral surface, known as lemniscal trigone, to understand better their microanatomy and their functional importance in the clinical practice during the microsurgical approach to this area. Methods: Eighty-seven alcohol-fixed cadaveric hemispheres (44 brains) without any pathological lesions provided the material for studying the perforating vessels and their origin around the dorsolateral midbrain using an operating microscope (OPMI 1 FC, Zeiss). Measurements of the perforators' distances, in relation to the parent vessels, were taken using a digital caliper. Results: An origin from the SCA could be found in 70.11% (61) and from the PCA in 27.58% (24) of the hemispheres. In one hemisphere, an origin from the posterior choroidal artery was found (4.54%). No perforating branches were discovered in 8.04% of specimens (7). Conclusion: The perforating arteries of the lemniscal trigone stem not only from the superior cerebellar artery (SCA), as described in the few studies available in literature, but also from the posterior cerebral artery (PCA). Therefore, special attention should be paid during surgery to spare those vessels and associated perforators. A comprehensive understanding of the lemniscal trigone's perforating arteries is vital to avoid infarction of the brainstem when treating midbrain tumors or vascular malformations. [ABSTRACT FROM AUTHOR]

Statistical Shape Models (SSMs) are widely used in orthopedics to extract the main shape features from bone regions (e.g., femur). This study aims to develop an SSM of the femoral medullary canal, investigate its anatomical variability, and assess variations depending on canal length. The canals were isolated from 72 CT femur scans, through a threshold-based segmentation. A region of interest (ROI) was selected; sixteen segments were extracted from the ROI, ranging from 25% of the full length down to the most distal segment. An SSM was developed to identify the main modes of variation for each segment. The number of Principal Components (PCs) needed to explain at least 90% of the shape variance were three/four based on the length of the canal segment. The study examined the relationship between the identified PCs and geometric parameters like length, radius of curvature, ellipticity, mean diameter, and conicity, reporting range and percentage variation of these parameters for each segment. The SSMs provide insights into the anatomical variability of the femoral canal, emphasizing the importance of considering different segments to capture shape variations at various canal length. These findings can contribute for the design of personalized orthopedic implants involving the distal femur., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Betti, Aldieri and Cristofolini.)

This study reports an unusual variant of drainage of the small saphenous vein identified during routine anatomic dissection of a male cadaver at the Human Anatomy Department. Both the right and left small saphenous veins did not drain into the popliteal vein, but continued proximally on the thigh as the deep femoral vein which, in turn, drained into the femoral vein. The left small saphenous vein showed some peculiarities compared to that of the opposite side: presence of the intergemellar perforating vein at the calf, a perforating vein at the popliteal fossa, and Giacomini`s vein at the thigh. Knowledge about the anatomical variability of the small saphenous vein is important for vascular and cardiac surgeons, for radiologists and anatomists.

In classic anatomy teaching, the brachial plexus generally features as an enigmatic rote‐learned structure, leaving the student with a feeling of complexity. The notion of complexity may increase in dissections, where plexuses significantly differing from the standard plexus model are readily found. This raises questions: what determines the existence and prevalence of variants and to what degree should they be considered anomalous? A model linking brachial plexus morphology and its variability to causative morphological parameters which would also standardize plexus description and teaching would be beneficial. The present study aims to provide such a model by analyzing the context of plexus development and applying this model in the analysis of plexus variability in anatomical specimens. Based on a thorough literature review, a generic developmental model was formulated and different factors of variability defined. In 56 plexuses, the proposed generic principles of plexus variability were found consistent with the variations encountered. Summarized, the modeled generic principles are as follows. Brachial plexus axon bundles grow out into an environment of chemical tracer paths in which constraints and obstacles are present: the geometry of the arm bud, cartilaginous bone precursors and vessels. The overall constancy of these factors generates a gross plexus outline, while the variability in these factors gives rise to typical plexus variations. The usefulness of the model derives from the fact that the variability of the main morphologically determining factors is not random but is the expression of the possibilities of the embryological substrate. Within the model, the major plexus morphological determinant is the segmental position of the subclavian artery, which is determined by the segment level of the intersegmental artery from which it develops. Normally, the subclavian artery develops from intersegmental artery i7. However, the subclavian artery can develop from inferior or superior segmental levels, from intersegmental artery i8 or i6, and possibly also from i9 or i5. Each of these arterial variants creates a typical, morphologically distinct, predictable plexus configuration. Superimposed on these basic plexus configurations, the underlying embryological substrate may develop further variability by integrating remnants of other intersegmental arteries into the arterial network. The resulting plexus configurations are further modified by local factors, e.g. the splitting of outgrowing axon bundles around vessels. A large split in the lateral cord around a large vein or veins crossing from lateral to medial, tangentially cranially over the subclavian artery was found in 54% of the 56 investigated BP and therefore might be added to plexus teaching. The distinct plexus morphologies associated with the subclavian artery segmental levels were further found associated with, among others, typical variations in the pectoral nerves and their ansas; these associations were also modeled. The presented models could allow brachial plexus rote learning to be replaced by a more insightful narrative of formative principles suitable for teaching. Clinically, improved understanding of the relationship between plexus variability and the local anatomical environment should be relevant to brachial plexus surgery and reconstruction. [ABSTRACT FROM AUTHOR]

Purpose: Knowledge of accessory flexor carpi ulnaris (AFCU) is not only important for proper orientation in the surgical field but it can be used for tendon transfer as well. AFCU commonly occurs with concomitant variants, and its presence should rise caution in order to prevent iatrogenic injury. Methods: During a routine dissection for research data collection at the Institute of Anatomy, a AFCU with concomitant variants was observed in a European cadaver fixed with Thiel's method. A thorough review of the literature concerning all the encountered variants was performed. Results: AFCU was found in the right upper limb with its insertion on the flexor retinaculum. Palmaris longus muscle was absent in this limb, and an accessory branch of the anterior interosseous artery coursed over the pronator quadratus muscle to anastomose with the ulnar artery 5 cm proximally to the pisiform. On the left hand, a variable lumbrical of the second finger originating from the flexor retinaculum was found, which was not described in the literature before. Conclusions: AFCU commonly occurs together with concomitant variants, and special attention is needed when performing surgery on such forearm. [ABSTRACT FROM AUTHOR]

The mechanics of the lumbar spine are heavily dependent on the underlying anatomy. Anatomical measures are used to assess the progression of pathologies related to low back pain and to screen patients for surgical treatment options. To describe anatomical norms and pathological differences for the population, statistical shape modeling, which uses full three-dimensional representations of bone morphology and relative alignment, can capture intersubject variability and enable comparative evaluations of subject to population. Accordingly, the objective of this study was to develop a comprehensive set of three-dimensional statistical models to characterize anatomical variability in the lumbar spine, by specifically describing the shape of individual vertebrae, and shape and alignment of the entire lumbar spine (L1-S1), with a focus on the L4-L5 and L5-S1 functional spinal units (FSU). Using CT scans for a cohort of 52 patients, lumbar spine geometries were registered to a template to establish correspondence and a principal component analysis identified the primary modes of variation. Scaling was the most prevalent mode of variation for all models. Subsequent modes of the statistical shape models of the individual bones characterized shape variation within the processes. Subsequent modes of variation for the FSU and entire spine models described alignment changes associated with disc height and lordosis. Quantification of anatomical variation in the spine with statistical models can inform implant design and sizing, assist clinicians in diagnosing pathologies, screen patients for treatment options, and support pre-operative planning. [ABSTRACT FROM AUTHOR]

Introduction. Morphological changes of the cerebellar lobules are found in many congenital and acquired diseases of the cerebellum, but the information on the normal structure of the cerebellar lobules do not take into account the peculiarities of individual anatomical variability, sex and age characteristics. Aim – to investigate anatomical variability and fractal dimension of the white matter of the human cerebellar hemispheres. Material and methods. The study involved 100 cerebella of people of both sexes, who died of causes unrelated to brain pathology (20–99 years old). Parasagittal sections of the cerebellar hemispheres were investigated. Results. On parasagittal sections number of main branches of white matter is very varied and depends on peculiarities of structure of the hemispheric lobules. It was found that there is individual variability of the structure of the human cerebellar hemispheres, namely white matter branching features. We described variants of the branching of the main branches of white matter of the human cerebellar hemispheres. Fractal dimension of the white matter was determined. The white matter of the cerebellum is typical quasi-fractal structure that can be objectively described using fractal dimension. Fractal index of the white matter of the cerebellar hemispheres varies from 1.119 to 1.519; average fractal index is 1.370. Fractal analysis can be used as an objective morphometric criterion for the diagnosis of various diseases of the cerebellum and other structures of the central nervous system. Conclusions. Described variants of the cerebellar lobules and fractal dimension can be used as criteria for modern diagnostic imaging techniques for the diagnosis of various diseases of the CNS. The data can be used as the basis for atlases of serial sections of the cerebellum.

Rational The human perirhinal cortex (PRC) plays critical roles in episodic and semantic memory and visual perception. The PRC consists of Brodmann areas 35 and 36 (BA35, BA36). In Alzheimer's disease (AD), BA35 is the first cortical site affected by neurofibrillary tangle pathology, which is closely linked to neural injury in AD. Large anatomical variability, manifested in the form of different cortical folding and branching patterns, makes it difficult to segment the PRC in MRI scans. Pathology studies have found that in ~97% of specimens, the PRC falls into one of three discrete anatomical variants. However, current methods for PRC segmentation and morphometry in MRI are based on single-template approaches, which may not be able to accurately model these discrete variants Methods A multi-template analysis pipeline that explicitly accounts for anatomical variability is used to automatically label the PRC and measure its thickness in T2-weighted MRI scans. The pipeline uses multi-atlas segmentation to automatically label medial temporal lobe cortices including entorhinal cortex, PRC and the parahippocampal cortex. Pairwise registration between label maps and clustering based on residual dissimilarity after registration are used to construct separate templates for the anatomical variants of the PRC. An optimal path of deformations linking these templates is used to establish correspondences between all the subjects. Experimental evaluation focuses on the ability of single-template and multi-template analyses to detect differences in the thickness of medial temporal lobe cortices between patients with amnestic mild cognitive impairment (aMCI, n=41) and age-matched controls (n=44). Results The proposed technique is able to generate templates that recover the three dominant discrete variants of PRC and establish more meaningful correspondences between subjects than a single-template approach. The largest reduction in thickness associated with aMCI, in absolute terms, was found in left BA35 using both regional and summary thickness measures. Further, statistical maps of regional thickness difference between aMCI and controls revealed different patterns for the three anatomical variants. [ABSTRACT FROM AUTHOR]