scholarly journals DIGITAL RECONSTRUCTION OF SOFT-TISSUE STRUCTURES IN FOSSILS

2016 ◽  
Vol 22 ◽  
pp. 101-117 ◽  
Author(s):  
Stephan Lautenschlager

AbstractIn the last two decades, advances in computational imaging techniques and digital visualization have created novel avenues for the study of fossil organisms. As a result, paleontology has undergone a shift from the pure study of physically preserved bones and teeth, and other hard tissues, to using virtual computer models to study specimens in greater detail, restore incomplete specimens, and perform biomechanical analyses. The rapidly increasing application of these techniques has further paved the way for the digital reconstruction of soft-tissue structures, which are rarely preserved or otherwise available in the fossil record. In this contribution, different types of digital soft-tissue reconstructions are introduced and reviewed. Provided examples include methodological approaches for the reconstruction of musculature, endocranial components (e.g., brain, inner ear, and neurovascular structures), and other soft tissues (e.g., whole-body and life reconstructions). Digital techniques provide versatile tools for the reconstruction of soft tissues, but given the nature of fossil specimens, some limitations and uncertainties remain. Nevertheless, digital reconstructions can provide new information, in particular if interpreted in a phylogenetically grounded framework. Combined with other digital analytical techniques (e.g., finite element analysis [FEA], multibody dynamics analysis [MDA], and computational fluid dynamics [CFD]), soft-tissue reconstructions can be used to elucidate the paleobiology of extinct organisms and to test competing evolutionary hypotheses.

2021 ◽  
Vol 23 (9) ◽  
Author(s):  
Andrea Di Matteo ◽  
Gianluca Smerilli ◽  
Edoardo Cipolletta ◽  
Fausto Salaffi ◽  
Rossella De Angelis ◽  
...  

Abstract Purpose of Review To highlight the potential uses and applications of imaging in the assessment of the most common and relevant musculoskeletal (MSK) manifestations in systemic lupus erythematosus (SLE). Recent Findings Ultrasound (US) and magnetic resonance imaging (MRI) are accurate and sensitive in the assessment of inflammation and structural damage at the joint and soft tissue structures in patients with SLE. The US is particularly helpful for the detection of joint and/or tendon inflammation in patients with arthralgia but without clinical synovitis, and for the early identification of bone erosions. MRI plays a key role in the early diagnosis of osteonecrosis and in the assessment of muscle involvement (i.e., myositis and myopathy). Conventional radiography (CR) remains the traditional gold standard for the evaluation of structural damage in patients with joint involvement, and for the study of bone pathology. The diagnostic value of CR is affected by the poor sensitivity in demonstrating early structural changes at joint and soft tissue level. Computed tomography allows a detailed evaluation of bone damage. However, the inability to distinguish different soft tissues and the need for ionizing radiation limit its use to selected clinical circumstances. Nuclear imaging techniques are valuable resources in patients with suspected bone infection (i.e., osteomyelitis), especially when MRI is contraindicated. Finally, dual energy X-ray absorptiometry represents the imaging mainstay for the assessment and monitoring of bone status in patients with or at-risk of osteoporosis. Summary Imaging provides relevant and valuable information in the assessment of MSK involvement in SLE.


Author(s):  
Sebastian Halm ◽  
David Haberthür ◽  
Elisabeth Eppler ◽  
Valentin Djonov ◽  
Andreas Arnold

Abstract Introduction This pilot study explores whether a human Thiel-embalmed temporal bone is suitable for generating an accurate and complete data set with micro-computed tomography (micro-CT) and whether solid iodine-staining improves visualization and facilitates segmentation of middle ear structures. Methods A temporal bone was used to verify the accuracy of the imaging by first digitally measuring the stapes on the tomography images and then physically under the microscope after removal from the temporal bone. All measurements were compared with literature values. The contralateral temporal bone was used to evaluate segmentation and three-dimensional (3D) modeling after iodine staining and micro-CT scanning. Results The digital and physical stapes measurements differed by 0.01–0.17 mm or 1–19%, respectively, but correlated well with the literature values. Soft tissue structures were visible in the unstained scan. However, iodine staining increased the contrast-to-noise ratio by a factor of 3.7 on average. The 3D model depicts all ossicles and soft tissue structures in detail, including the chorda tympani, which was not visible in the unstained scan. Conclusions Micro-CT imaging of a Thiel-embalmed temporal bone accurately represented the entire anatomy. Iodine staining considerably increased the contrast of soft tissues, simplified segmentation and enabled detailed 3D modeling of the middle ear.


Author(s):  
Stephanie Panzer ◽  
Patrizia Pernter ◽  
Dario Piombino-Mascali ◽  
Rimantas Jankauskas ◽  
Stephanie Zesch ◽  
...  

Purpose Soft tissues make a skeleton into a mummy and they allow for a diagnosis beyond osteology. Following the approach of structured reporting in clinical radiology, a recently developed checklist was used to evaluate the soft tissue preservation status of the Tyrolean Iceman using computed tomography (CT). The purpose of this study was to apply the “Checklist and Scoring System for the Assessment of Soft Tissue Preservation in CT Examinations of Human Mummies” to the Tyrolean Iceman, and to compare the Iceman’s soft tissue preservation score to the scores calculated for other mummies. Materials and Methods A whole-body (CT) (SOMATOM Definition Flash, Siemens, Forchheim, Germany) consisting of five scans, performed in January 2013 in the Department of Radiodiagnostics, Central Hospital, Bolzano, was used (slice thickness 0.6 mm; kilovolt ranging from 80 to 140). For standardized evaluation the “CT Checklist and Scoring System for the Assessment of Soft Tissue Preservation in Human Mummies” was used. Results All checkpoints under category “A. Soft Tissues of Head and Musculoskeletal System” and more than half in category “B. Organs and Organ Systems” were observed. The scoring system accounted for a total score of 153 (out of 200). The comparison of the scores between the Iceman and three mummy collections from Vilnius, Lithuania, and Palermo, Sicily, as well as one Egyptian mummy resulted in overall higher soft tissue preservation scores for the Iceman. Conclusion Application of the checklist allowed for standardized assessment and documentation of the Iceman’s soft tissue preservation status. The scoring system allowed for a quantitative comparison between the Iceman and other mummies. The Iceman showed remarkable soft tissue preservation. Key Points  Citation Format


Author(s):  
Islam Talaat Khalil Attia ◽  
Ali Mahmoud Emran ◽  
Elhafez Abd Elgafez Megahed ◽  
Mamdouh Fouad Lashin

Background: Ulnar-sided wrist pain is a common cause of upper- extremity disability. Presentation can vary from acute traumatic injuries to chronic degenerative conditions. Carful clinical examination should be done, there are some provocative tests for some pathologies which induce pain when the patient has the specific pathology for the test. MRI of the wrist is often challenging because the components of the wrist have complex anatomy of bone and soft tissues, with ligaments and cartilage which are small sized structures measuring millimeters. MRI is a one of advanced imaging techniques that play an important role in evaluating the wrist and is a useful examination modality because of its multiplanar, multisequence capability and its excellent resolution of soft tissue structures. MRI is particularly advantageous for assessing occult bone lesions and soft tissue structures around the wrist such as cartilages, tendons, ligaments and nerves. Aim: The aim of this study is to assess the role and accuracy of clinical tests and MRI in diagnosis of chronic ulnar-sided wrist pain causes. Patients and Methods: This is a prospective study and was conducted on a 50 adult patients complaining from chronic ulnar side wrist pain. They were attended to Orthopedic Department of Tanta University Hospitals over a period of 6 months starting from November 2019 till May 2020. Results: MRI gave positive finding in most of patients (92%), while negative in about (8%) of cases, this means that there are some pathologies need more investigations to be diagnosed. Most of Clinical tests also gave a help in diagnosis of the cause of the pain especially ulnocarpal stress test, fovea sign test, ECU synergy test and piano key test which by statistics showed significant results but LT ballottement test had insignificant results so LTL pathology can't be diagnosed by clinical tests only but needs more investigations as MRI. So some pathologies can be diagnosed clinically as ECU tenosynovitis, but other pathologies need more investigations like MRI like LTL tear, also some pathologies need more investigations. Conclusion: Most of clinical tests give significant results in diagnosis of chronic ulnar-sided wrist pain except for some pathologies like LTL tear needs more investigations, also MRI has important role and gives significant results in diagnosis.


2014 ◽  
Vol 20 ◽  
pp. 275-288 ◽  
Author(s):  
John A. Cunningham ◽  
Philip C. J. Donoghue ◽  
Stefan Bengtson

Knowledge of evolutionary history is based extensively on relatively rare fossils that preserve soft tissues. These fossils record a much greater proportion of anatomy than would be known solely from mineralized remains and provide key data for testing evolutionary hypotheses in deep time. Ironically, however, exceptionally preserved fossils are often among the most contentious because they are difficult to interpret. This is because their morphology has invariably been affected by the processes of decay and diagenesis, meaning that it is often difficult to distinguish preserved biology from artifacts introduced by these processes. Here we describe how a range of analytical techniques can be used to tease apart mineralization that preserves biological structures from unrelated geological mineralization phases. This approach involves using a series of X-ray, ion, electron and laser beam techniques to characterize the texture and chemistry of the different phases so that they can be differentiated in material that is difficult to interpret. This approach is demonstrated using a case study of its application to the study of fossils from the Ediacaran Doushantuo Biota.


2017 ◽  
Vol 5 ◽  
pp. 2050313X1774182
Author(s):  
Maria Grazia Caprio ◽  
Mariarosaria Manganelli ◽  
Simona Limone ◽  
Massimiliano Sorbillo ◽  
Mario Quarantelli ◽  
...  

Bone scintigraphy is a nuclear scanning test used to find abnormalities in the skeleton. Certain abnormal processes involving soft tissues can also cause skeletal accumulation of radiotracer during bone scintigraphy. We present a case of periarticular knee soft tissue 99mTc methylene diphosphonate uptake in a patient with asymmetric polyarthritis. A 33-year-old patient with asymmetric polyarthritis, skin lesions and joint pain underwent bone scintigraphy. Total body examination showed an extra-osseous uptake in periarticular soft tissue of knees joints. A detailed history checkup, physical examination and laboratory tests were carried out to understand the link between the extra-osseous uptake and the phosphonate binding in periarticular soft tissue. To improve the anatomical description of the soft tissue of the knees and to clarify the nature of the extra-skeletal 99mTc methylene diphosphonate uptake, magnetic resonance imaging scan was performed. 99mTc-labeled phosphonate binding has been reported in a number of extra-osseous conditions, but to our knowledge, there are a few cases showing bone tracer uptake in polyarthritis. In polyarthritic patients, whole-body bone scintigraphy were useful in examining the whole joints and detecting possible dubious extra-osseous uptake; in fact, it is able to select subjects who require further in-depth analysis, for example, magnetic resonance imaging.


Author(s):  
C. P. Arun

Soft tissues hollow structures are capable of collapsing not only under their own power but also able to employ movements of their neighbors to aid their function of propelling content. An intensive study of collapsible hollow structures is a recent development and no general law recognising this convenient coupling of the dynamics of neighboring organs is available in the literature. The literature on whole organ physiology was analysed and examples of neighboring organs providing assistance to soft tissue structures was collected. We offer the title Covenant of NOA to the arrangement that soft tissue structures have with their neighbors. The calf muscle pump and parturition are obvious examples of NOA. From examining videocystometric recordings, we are able to offer, as the latest to a long list of known NOAs, the assistance of the pelvic diaphragm to the urinary bladder that aids the latter in emptying completely. The modeling of soft tissue hollow organs as functioning somewhat in isolation must be considered antediluvian. Very often, soft tissue structures come in pairs to implement NOA: it is time we too hearkened to the Covenant of NOA.


Author(s):  
V. N. Druzhinin ◽  
V. G. Suvorov ◽  
A. N. Cherny ◽  
S. N. Troynakov ◽  
U. T. Tukhtaev

Introduction. Timely and adequate diagnosis and treatment of degenerative-dystrophic diseases of the bone and joint apparatus, which include epicondylitis (epicondylosis), including professionally caused, continues to be a serious health problem today, since they cause significant economic damage associated with temporary and persistent disability of the active part of the world’s population. In this regard, the search for methods and methodological approaches to improve the radiation diagnosis of this disease remains relevant. The study is devoted to solution of important medical problems, including occupational diseases-optimization of X-ray of the ulnar epicondylitis based on the use of new methodological approaches quantifying the density of pathological remodeling of bone structures in the subject area, that allow to objectify the direction of changes in monitoring intensity changes in the estimated structures.The aim of the study is to improve the quality of x-ray diagnostics of ulnar epicondylitis based on a precision assessment of the optical density of bone and periarticular tissues using digital radiography.Materials and methods. A comparative analysis of the results of a comprehensive clinical and radiological examination of patients, workers of the main group (fitters and laborers machine-building plants) working age range of 30–50 years with a clinical picture of subacute phase of the ulnar epicondylitis in the absence of a pathognomonic ultrasound findings and x-ray morphological signs of the disease. X-ray studies were performed using digital low-dose x-ray diagnostic devices. Visualization, processing, analysis of medical images and comparison of results in the dynamics of research were carried out using the programs «Lins machaon doctor’s workstation». To measure the conditional optical density of bone and soft tissues, we used the ROI tool (zone of interest), which allows us to determine the desired value in areas of different dimensions. Measurements were performed on digital radiographs and computer monitor screens in the areas of interest: the lateral parts of the humerus condyles and adjacent periarticular tissues with the calculation of the average values of the optical density index (ID) and optical density gradients (IDG) relative to the density of periarticular soft tissues.Results. Analysis of the results of a posteriori osteodensitometry of the distal humerus within the framework of the developed algorithm, which includes the use of absolute and relative indicators of conditional optical density after preliminary color correction of digital x-ray images of bone and paraossal tissue structures, allowed us to expand our understanding of the topography of the distribution of mineral saturation in the condyles of at-risk individuals relative to those of the control group. It was found that the indicators of optical density of bone and paraossal tissues can be a kind of (conditional), sometimes the only indicators of the degree of severity of changes, positive or negative dynamics of pathophysiological processes. Density differences in the distal parts of the right and left humerus (bony and soft -tissue paraossal structures of the condyles) in the control group (conditional norm) in terms of absolute optical density and its gradient, regardless of the assessment area, were insignificant (statistically unreliable), although they were multidirectional. In patients with clinical signs of epicondylitis in the absence of x-ray morphologically detectable structural changes, a decrease in ID and the dynamics of its recovery at various stages of observation were revealed. Even when the ID of the actual bone structure is relatively equal, the IDG differs in different people, since it is largely determined by metabolic processes that are dynamically more labile than in the bones, and thus serve as a kind of indicator of their intensity. Taking into account the relative torpidity of perestroika processes in the structures of the bone tissue of the condyles in epicondylitis, IDG should be considered a more informative indicator of their dynamics. The importance of optical density indicators as predictors of the considered pathology is particularly evident in the process of analyzing the results of its diagnosis and development in the dynamics of observations not so much at the collective as at the individual level of assessment.Conclusions. The application of the developed methodological approach allows us to significantly expand our understanding of the topographical distribution of the density of bone and soft tissue structures of the distal humerus at various stages of examination of patients, including the early subclinical phases of possible pathology, even in the absence of visually detectable x-ray morphological changes. The use of an original algorithm for evaluating tissue density will reduce the negative role of the so-called «human factor» and thus significantly ensure the objectivity of the interpretation of research results.Funding. The study had no funding.Conflict of interests. The authors declare no conflict of interests.


2020 ◽  
Vol 18 (3) ◽  
pp. 200-209
Author(s):  
Ahmed Fouly ◽  
Ahmed M. R. FathEl-Bab ◽  
A. A. Abouelsoud ◽  
T. Tsuchiya ◽  
O. Tabata

Tactile sensors become an essential part of many applications in our life. Integrating tactile sensors with surgical tools used in MIS is significant to compensate for the shortage of touch feeling of soft tissues and organs comparing with traditional surgeries. This paper presents a detailed design of a micro tactile sensor for measuring the stiffness of soft tissue with an irregular surface. The sensor consists of five cantilever springs with different stiffness. A spring in the middle has a relatively low stiffness surrounded by 4 springs have relatively equal high stiffness to compensate for the soft tissue contact error in the longitudinal and lateral directions. Sensor parameters are selected to ensure high sensitivity and linearity with taking into consideration the cross-talk effect among the sensor springs tips. A detailed design of the sensor structure in the microscale is conducted based on some constraints related to MEMS fabrication. A finite element analysis (FEA) of the sensor structure is conducted to evaluate sensor structure performance using CoventorWare software. Then, an FEA for the piezo-resistors, as a signal transduction method, is conducted which maps the sensor output to an electrical signal. The results prove that the sensor can differentiate among different soft-tissue stiffness within the selected range independent of the applied distance between the sensor and the tissue with an error below 3% even with inclination angle between the sensor and the tissue ±3°. Furthermore, a linear performance has been achieved between the soft-tissue stiffness and the sensor output.


2021 ◽  
Author(s):  
Tim J. van der Zee ◽  
Arthur D. Kuo

AbstractHumans perform mechanical work during walking, some by leg joints actuated by muscles, and some by passive, dissipative soft tissues. Dissipative losses must be restored by active muscle work, potentially in amounts sufficient to cost substantial metabolic energy. The most dissipative, and therefore costly, walking conditions might be predictable from the pendulum-like dynamics of the legs. If pendulum behavior is systematic, it may also predict the work distribution between active joints and passive soft tissues. We therefore tested whether the overall negative work of walking, and the fraction due to soft tissue dissipation, are both predictable by a pendulum model across a wide range of conditions. The model predicts whole-body negative work from the leading leg’s impact with ground (termed the Collision), to increase with the squared product of walking speed and step length. We experimentally tested this in humans (N = 9) walking in 26 different combinations of speed (0.7 – 2.0 m·s-1) and step length (0.5 – 1.1 m), with recorded motions and ground reaction forces. Whole-body negative Collision work increased as predicted (R2= 0.73), with a consistent fraction of about 63% (R2= 0.88) due to soft tissues. Soft tissue dissipation consistently accounted for about 56% of the variation in total whole-body negative work. During typical walking, active work to restore dissipative losses could account for 31% of the net metabolic cost. Soft tissue dissipation, not included in most biomechanical studies, explains most of the variation in negative work of walking, and could account for a substantial fraction of the metabolic cost.Summary statementSoft tissue deformations dissipate substantial energy during human walking, as predicted by a simple walking model.


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