scholarly journals Identification of Regional Mechanical Anisotropy in Soft Tissue Analogs

2011 ◽  
Vol 133 (9) ◽  
Author(s):  
Ramesh Raghupathy ◽  
Colleen Witzenburg ◽  
Spencer P. Lake ◽  
Edward A. Sander ◽  
Victor H. Barocas
Keyword(s):  
Soft Tissue ◽  
Regional Differences ◽  
Soft Tissues ◽  
Tissue Sample ◽  
Polarized Light ◽  
Simulated Data ◽  
Material Behavior ◽  
Mechanical Anisotropy ◽  
Structural Anisotropy ◽  
Full Field

In a previous work (Raghupathy and Barocas, 2010, “Generalized Anisotropic Inverse Mechanics for Soft Tissues,”J. Biomech. Eng., 132(8), pp. 081006), a generalized anisotropic inverse mechanics method applicable to soft tissues was presented and tested against simulated data. Here we demonstrate the ability of the method to identify regional differences in anisotropy from full-field displacements and boundary forces obtained from biaxial extension tests on soft tissue analogs. Tissue heterogeneity was evaluated by partitioning the domain into homogeneous subdomains. Tests on elastomer samples demonstrated the performance of the method on isotropic materials with uniform and nonuniform properties. Tests on fibroblast-remodeled collagen cruciforms indicated a strong correlation between local structural anisotropy (measured by polarized light microscopy) and the evaluated local mechanical anisotropy. The results demonstrate the potential to quantify regional anisotropic material behavior on an intact tissue sample.

Anisotropic Inverse Mechanics Identifies Regional Changes in Mechanical Anisotropy During Remodelling of Fibroblast-Populated Collagen Cruciforms

2011 ◽  
Author(s):  
Ramesh Raghupathy ◽  
Spencer P. Lake ◽  
Edward A. Sander ◽  
Colleen Witzenburg ◽  
Victor H. Barocas
Keyword(s):  
Anisotropic Material ◽  
Soft Tissues ◽  
Material Behavior ◽  
Mechanical Anisotropy ◽  
Tissue Samples ◽  
Intact Tissue ◽  
Tissue Equivalents ◽  
Standard Tests ◽  
Collagen Tissue

Most elastographic methods applied to soft tissues assume either isotropy or homogeneity in the sample. While this assumption is valid in specific cases, general methods that can identify regional changes in mechanical anisotropy have many advantages. Chiefly, such methods could quantify regional anisotropic material behavior on intact tissue samples especially when the tissue is heterogeneous and too small for standard tests. In this study we use an inverse mechanics method which handles both anisotropy and heterogeneity to track changes in mechanical anisotropy associated with remodeling in cell-compacted collagen tissue equivalents (TE), which are then compared with measurements from polarimetry to estimate the method’s accuracy.

Generalized Anisotropic Inverse Mechanics: Mechanical Anisotropy Correlates With Structural Anisotropy in Collagen Based Tissue Equivalents

2010 ◽  
Author(s):  
Ramesh Raghupathy ◽  
Spencer P. Lake ◽  
Edward A. Sander ◽  
Victor H. Barocas
Keyword(s):  
Blood Vessels ◽  
Soft Tissues ◽  
Mechanical Anisotropy ◽  
Underlying Structure ◽  
Test Case ◽  
Inhomogeneous Materials ◽  
Structural Anisotropy ◽  
Fiber Alignment ◽  
Load Bearing ◽  
Tissue Equivalents

Few elastographic methods handle both anisotropy and inhomogeneity. Much of the focus has been on inhomogeneous materials that are locally isotropic. However, most load-bearing tissues (heart, ligament, blood vessels) are highly anisotropic, and the underlying structure is distinct and essential for function. With disease or damage, this structure is altered, and hence the potential for an elastographic tool that identifies regional changes in anisotropy is high. In this study we present a generalized anisotropic inverse mechanics (GAIM) method that is applicable to soft tissues and demonstrate its performance on tissue equivalents which serve as a convenient test case due to their inhomogeneity and the ease of pre-specifying the fiber alignment pattern.

Imaging Features of Primary Tumors of the Hand

2020 ◽  
Vol 16 ◽  
Author(s):  
Filippo Boriani ◽  
Edoardo Raposio ◽  
Costantino Errani
Keyword(s):  
Soft Tissue ◽  
Soft Tissues ◽  
Epithelioid Sarcoma ◽  
Case Series ◽  
Malignant Neoplasm ◽  
Benign Tumors ◽  
Imaging Features ◽  
Primary Tumors ◽  
Therapeutic Decisions ◽  
Tumors Of The Hand

: Musculoskeletal tumors of the hand are a rare entity and are divided into skeletal and soft tissue tumors. Either category comprises benign and malignant or even intermediate tumors. Basic radiology allows an optimal resolution of bone and related soft tissue areas, ultrasound and more sophisticated radiologic tools such as scintigraphy, CT and MRI allow a more accurate evaluation of tumor extent. Enchondroma is the most common benign tumor affecting bone, whereas chondrosarcoma is the most commonly represented malignant neoplasm localized to hand bones. In the soft tissues ganglions are the most common benign tumors and epithelioid sarcoma is the most frequently represented malignant tumor targeting hand soft tissues. The knowledge regarding diagnostic and therapeutic management of these tumors is often deriving from small case series, retrospective studies or even case reports. Evidences from prospective studies or controlled trials are limited and for this lack of clear and supported evidences data from the medical literature on the topic are controversial, in terms of demographics, clinical presentation, diagnosis prognosis and therapy.The correct recognition of the specific subtype and extension of the tumor through first line and second line radiology is essential for the surgeon, in order to effectively direct the therapeutic decisions.

scholarly journals Developing a Quantifying Device for Soft Tissue Material Prop-Erties around Lumbar Spines

Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 67
Author(s):  
Song Joo Lee ◽  
Yong-Eun Cho ◽  
Kyung-Hyun Kim ◽  
Deukhee Lee
Keyword(s):  
Lumbar Spine ◽  
Soft Tissue ◽  
Young’S Modulus ◽  
Viscoelastic Properties ◽  
Soft Tissues ◽  
Young's Modulus ◽  
Strain Curve ◽  
Stress And Strain ◽  
Commercial Device ◽  
Tissue Material

Knowing the material properties of the musculoskeletal soft tissue could be important to develop rehabilitation therapy and surgical procedures. However, there is a lack of devices and information on the viscoelastic properties of soft tissues around the lumbar spine. The goal of this study was to develop a portable quantifying device for providing strain and stress curves of muscles and ligaments around the lumbar spine at various stretching speeds. Each sample was conditioned and applied for 20 repeatable cyclic 5 mm stretch-and-relax trials in the direction and perpendicular direction of the fiber at 2, 3 and 5 mm/s. Our device successfully provided the stress and strain curve of the samples and our results showed that there were significant effects of speed on the young’s modulus of the samples (p < 0.05). Compared to the expensive commercial device, our lower-cost device provided comparable stress and strain curves of the sample. Based on our device and findings, various sizes of samples can be measured and viscoelastic properties of the soft tissues can be obtained. Our portable device and approach can help to investigate young’s modulus of musculoskeletal soft tissues conveniently, and can be a basis for developing a material testing device in a surgical room or various lab environments.

scholarly journals Quantification of assembly forces during creation of head-neck taper junction considering soft tissue bearing: a biomechanical study

Arthroplasty ◽  
2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Toni Wendler ◽  
Torsten Prietzel ◽  
Robert Möbius ◽  
Jean-Pierre Fischer ◽  
Andreas Roth ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Work Experience ◽  
Soft Tissues ◽  
Force Sensor ◽  
Biomechanical Study ◽  
Measuring System ◽  
Wide Range ◽  
Head Neck

Abstract Background All current total hip arthroplasty (THA) systems are modular in design. Only during the operation femoral head and stem get connected by a Morse taper junction. The junction is realized by hammer blows from the surgeon. Decisive for the junction strength is the maximum force acting once in the direction of the neck axis, which is mainly influenced by the applied impulse and surrounding soft tissues. This leads to large differences in assembly forces between the surgeries. This study aimed to quantify the assembly forces of different surgeons under influence of surrounding soft tissue. Methods First, a measuring system, consisting of a prosthesis and a hammer, was developed. Both components are equipped with a piezoelectric force sensor. Initially, in situ experiments on human cadavers were carried out using this system in order to determine the actual assembly forces and to characterize the influence of human soft tissues. Afterwards, an in vitro model in the form of an artificial femur (Sawbones Europe AB, Malmo, Sweden) with implanted measuring stem embedded in gelatine was developed. The gelatine mixture was chosen in such a way that assembly forces applied to the model corresponded to those in situ. A study involving 31 surgeons was carried out on the aforementioned in vitro model, in which the assembly forces were determined. Results A model was developed, with the influence of human soft tissues being taken into account. The assembly forces measured on the in vitro model were, on average, 2037.2 N ± 724.9 N, ranging from 822.5 N to 3835.2 N. The comparison among the surgeons showed no significant differences in sex (P = 0.09), work experience (P = 0.71) and number of THAs performed per year (P = 0.69). Conclusions All measured assembly forces were below 4 kN, which is recommended in the literature. This could lead to increased corrosion following fretting in the head-neck interface. In addition, there was a very wide range of assembly forces among the surgeons, although other influencing factors such as different implant sizes or materials were not taken into account. To ensure optimal assembly force, the impaction should be standardized, e.g., by using an appropriate surgical instrument.

scholarly journals Imaging of Joint and Soft Tissue Involvement in Systemic Lupus Erythematosus

2021 ◽  
Vol 23 (9) ◽  
Author(s):  
Andrea Di Matteo ◽  
Gianluca Smerilli ◽  
Edoardo Cipolletta ◽  
Fausto Salaffi ◽  
Rossella De Angelis ◽  
...  
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Soft Tissue ◽  
Lupus Erythematosus ◽  
Structural Damage ◽  
Structural Changes ◽  
Soft Tissues ◽  
Imaging Techniques ◽  
Joint Involvement ◽  
Systemic Lupus ◽  
Muscle Involvement

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.

scholarly journals Micro-CT imaging of Thiel-embalmed and iodine-stained human temporal bone for 3D modeling

2021 ◽  
Vol 50 (1) ◽  
Author(s):  
Sebastian Halm ◽  
David Haberthür ◽  
Elisabeth Eppler ◽  
Valentin Djonov ◽  
Andreas Arnold
Keyword(s):  
Soft Tissue ◽  
Temporal Bone ◽  
Middle Ear ◽  
3D Modeling ◽  
Soft Tissues ◽  
Ct Imaging ◽  
Micro Ct ◽  
Data Set ◽  
Iodine Staining ◽  
Tissue Structures

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.

Orthodontic Pre Grafting Closure of Large Alveolar Bony and Soft Tissue Gaps: A Novel Nonsurgical Protraction of the Lesser Segments in Growing Patients With Cleft Lip and Palate

2021 ◽  
pp. 105566562110076
Author(s):  
Maria Costanza Meazzini ◽  
Noah Cohen ◽  
Valeria Marinella Augusta Battista ◽  
Cristina Incorvati ◽  
Federico Biglioli ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Surgical Procedures ◽  
Efficient Method ◽  
Bone Grafting ◽  
Cleft Lip ◽  
Soft Tissues ◽  
Cleft Lip And Palate ◽  
Face Mask ◽  
Younger Patients ◽  
Good Healing

Background: Closure of wide alveolar clefts with large soft tissue gaps and reconstruction of the dentoalveolar defect are challenging for the surgeon. Some authors successfully used interdental segmental distraction, which requires an additional surgical procedure. Objective: This study evaluates the effectiveness of tooth borne devices utilized to orthopedically advance the lesser segments, with a complete approximation of the soft tissue of the alveolar stumps, allowing traditional simultaneous soft tissue closure and bone grafting, and avoiding the need for supplementary surgery. Methods: Eight growing patients, 2 with unilateral complete cleft lip and palate (UCLP) and 6 with bilateral complete cleft lip and palate (BCLP), with large soft tissue and bony alveolar defects prior to bone grafting were prospectively selected. A banded rapid palatal expander (RPE) in BCLP and a modified RPE in UCLP combined with protraction face mask in younger patients or a modified Alt-Ramec in patients older than 12 years were applied. Radiographic and photographic records were available at T0, at the end of protraction (T1) and at least 1 year after bone grafting (T2). Results: Patients with large gaps showed a significant reduction in the bony cleft area and approximation of the soft tissues at T1. All patients received bone grafting with good healing and ossification at T2. Conclusion: In growing patients with UCLP and BCLP with large gaps, presurgical orthodontic protraction seems to be an efficient method to reduce the cleft defect, minimizing the risk of post grafting fistulas, reducing the need for supplementary surgical procedures.

scholarly journals Accuracy and Reliability of Soft Tissue Landmarks Using Three-Dimensional Imaging in Comparison With Two-Dimensional Cephalometrics: A Systematic Review

2020 ◽  
Vol 54 (4) ◽  
pp. 289-296
Author(s):  
Adeeba Ali ◽  
Anil K. Chandna ◽  
Anshul Munjal
Keyword(s):  
Systematic Review ◽  
Soft Tissue ◽  
3D Imaging ◽  
Soft Tissues ◽  
Three Dimensional ◽  
Database Search ◽  
Cochrane Library ◽  
Two Dimensional ◽  
Imaging Tool ◽  
Electronic Database Search

Background: Concerns about the accuracy and reliability of soft tissue landmarks using two-dimensional (2D) and three-dimensional (3D) imaging. Objective: The aim of the systematic review is to estimate accuracy and reliability of soft tissue landmarks with 2D imaging and 3D imaging for orthodontic diagnosis planning and treatment planning purposes. Data Sources: Electronic database search was performed in MEDLINE via PubMed, Embase via embase.com, and the Cochrane library website. Selection Criteria: The data were extracted according to two protocols based on Centre for Evidence-Based Medicine (CEBM) critical appraisal tools. Next, levels of evidence were categorized into three groups: low, medium, and high. Data Synthesis: Fifty-five publications were found through database search strategies. A total of nine publications were included in this review. Conclusion According to the available literature, 3D imaging modalities were more accurate and reliable as compared to 2D modalities. Cone beam computed tomography (CBCT) was considered the most reliable imaging tool for soft tissues.

scholarly journals An open-source FEniCS-based framework for hyperelastic parameter estimation from noisy full-field data: Application to heterogeneous soft tissues

2021 ◽  
Vol 255 ◽  
pp. 106620
Author(s):  
A. Elouneg ◽  
D. Sutula ◽  
J. Chambert ◽  
A. Lejeune ◽  
S.P.A. Bordas ◽  
...  
Keyword(s):  
Parameter Estimation ◽  
Open Source ◽  
Field Data ◽  
Soft Tissues ◽  
Full Field ◽  
Data Application
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