292 results match your criteria: "Institute for Surgical Technology and Biomechanics[Affiliation]"

Article Synopsis
  • Automated brain tumor segmentation methods have reached a level of performance that is clinically useful, relying on MRI modalities like T1, T2, and FLAIR images.
  • These methods often face challenges due to missing sequences caused by issues like time constraints and patient motion, making it crucial to find ways to substitute missing modalities for better segmentation.
  • The Brain MR Image Synthesis Benchmark (BraSyn) was established to evaluate image synthesis techniques that can generate these missing MRI modalities, aiming to enhance the automation of brain tumor segmentation processes.
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Deep learning (DL) models have provided state-of-the-art performance in various medical imaging benchmarking challenges, including the Brain Tumor Segmentation (BraTS) challenges. However, the task of focal pathology multi-compartment segmentation (e.g.

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Background: The T1-S1 distance to evaluate spinal length is traditionally measured as a straight line on an anteroposterior radiograph. However, this method may not reflect the true 3-dimensional (3D) spinal length. The objective of the study was to evaluate the difference between the traditional T1-S1 measurement and a 3D reconstruction from standard x-ray imaging.

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Following Graham et al. (2019), the recently described desert species Olivierus gorelovi (Fet et al., 2018) from Central Asia is herein restricted to Turkmenistan and southern Uzbekistan.

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Divide and Conquer: Stratifying Training Data by Tumor Grade Improves Deep Learning-Based Brain Tumor Segmentation.

Front Neurosci

November 2019

Support Center for Advanced Neuroimaging (SCAN), University Institute of Diagnostic and Interventional Neuroradiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.

It is a general assumption in deep learning that more training data leads to better performance, and that models will learn to generalize well across heterogeneous input data as long as that variety is represented in the training set. Segmentation of brain tumors is a well-investigated topic in medical image computing, owing primarily to the availability of a large publicly-available dataset arising from the long-running yearly Multimodal Brain Tumor Segmentation (BraTS) challenge. Research efforts and publications addressing this dataset focus predominantly on technical improvements of model architectures and less on properties of the underlying data.

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Muscle fat content in the intact infraspinatus muscle correlates with age and BMI, but not critical shoulder angle.

Eur J Trauma Emerg Surg

April 2021

Department of Orthopaedic Surgery and Traumatology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.

Purpose: Muscle fat content of the rotator cuff increases after a tear. In the healthy rotator cuff, the influence of age, body mass index (BMI) and critical shoulder angle (CSA) on muscle fat content is unknown. The primary aim was to correlate muscle fat content with age, BMI and CSA.

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Neural Network-derived Perfusion Maps for the Assessment of Lesions in Patients with Acute Ischemic Stroke.

Radiol Artif Intell

September 2019

Support Center for Advanced Neuroimaging-University Institute of Diagnostic and Interventional Neuroradiology (R. Meier, P.L., J.G., R.W., R. McKinley, J.K.), Department of Neurology (S.J., U.F., J.K.), Institute for Surgical Technology and Biomechanics (M.R.), and Institute for Diagnostic, Interventional and Pediatric Radiology (J.K.), University Hospital Inselspital and University of Bern, Freiburgstrasse 4, 3010 Bern, Switzerland.

Purpose: To perform a proof-of-concept study to investigate the clinical utility of perfusion maps derived from convolutional neural networks (CNNs) for the workup of patients with acute ischemic stroke presenting with a large vessel occlusion.

Materials And Methods: Data on endovascularly treated patients with acute ischemic stroke ( = 151; median age, 68 years [interquartile range, 59-75 years]; 82 of 151 [54.3%] women) were retrospectively extracted from a single-center institutional prospective registry (between January 2011 and December 2015).

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Background: Femoroacetabular impingement (FAI) is a complex 3-dimensional (3D) hip abnormality that can cause hip pain and osteoarthritis in young and active patients of childbearing age. Imaging is static and based on 2-dimensional radiographs or computed tomography (CT) scans. Recently, CT-based 3D impingement simulation was introduced for patient-specific assessments of hip deformities, whereas magnetic resonance imaging (MRI) offers a radiation-free alternative for surgical planning before hip arthroscopic surgery.

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Purpose: To determine surgical parameters for arcuate keratotomy by simulating the intervention with a patient-specific model.

Setting: University Eye Clinic Salzburg, Paracelsus Medical University, Austria, and Institute for Surgical Technology and Biomechanics, University of Bern, Switzerland.

Design: Computational modeling study.

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Holistic decomposition convolution for effective semantic segmentation of medical volume images.

Med Image Anal

October 2019

School of Biomedical Engineering, Shanghai Jiao Tong University, No.800 Dongchuan Road, Shanghai 200240, China. Electronic address:

Convolutional Neural Networks (CNNs) have achieved state-of-the-art performance in many different 2D medical image analysis tasks. In clinical practice, however, a large part of the medical imaging data available is in 3D, e.g, magnetic resonance imaging (MRI) data, computed tomography (CT) data and data generated by many other modalities.

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Novel adversarial semantic structure deep learning for MRI-guided attenuation correction in brain PET/MRI.

Eur J Nucl Med Mol Imaging

December 2019

Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospital, CH-1211, Geneva 4, Switzerland.

Objective: Quantitative PET/MR imaging is challenged by the accuracy of synthetic CT (sCT) generation from MR images. Deep learning-based algorithms have recently gained momentum for a number of medical image analysis applications. In this work, a novel sCT generation algorithm based on deep learning adversarial semantic structure (DL-AdvSS) is proposed for MRI-guided attenuation correction in brain PET/MRI.

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Clinical use of MRSI is limited by the level of experience required to properly translate MRSI examinations into relevant clinical information. To solve this, several methods have been proposed to automatically recognize a predefined set of reference metabolic patterns. Given the variety of metabolic patterns seen in glioma patients, the decision on the optimal number of patterns that need to be used to describe the data is not trivial.

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Human mesenchymal stromal cell (hMSC) secretomes have shown to influence the microenvironment upon injury, promoting cytoprotection, angiogenesis, and tissue repair. The angiogenic potential is of particular interest for the treatment of ischemic diseases. Interestingly, hMSC secretomes isolated from different tissue sources have shown dissimilarities with respect to their angiogenic profile.

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Automatic MRI-based Three-dimensional Models of Hip Cartilage Provide Improved Morphologic and Biochemical Analysis.

Clin Orthop Relat Res

May 2019

F. Schmaranzer, R. Helfenstein, T. D. Lerch, K. A. Siebenrock, M. Tannast, Department of Orthopaedic Surgery, Inselspital Bern, University of Bern, Switzerland, Bern, Switzerland G. Zeng, G. Zheng, Institute for Surgical Technology and Biomechanics, University of Bern, Switzerland, Bern, Switzerland F. Schmaranzer, E. N. Novais, J. D. Wylie, Y-J. Kim, Department of Orthopaedic Surgery, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.

Background: The time-consuming and user-dependent postprocessing of biochemical cartilage MRI has limited the use of delayed gadolinium-enhanced MRI of cartilage (dGEMRIC). An automated analysis of biochemical three-dimensional (3-D) images could deliver a more time-efficient and objective evaluation of cartilage composition, and provide comprehensive information about cartilage thickness, surface area, and volume compared with manual two-dimensional (2-D) analysis.

Questions/purposes: (1) How does the 3-D analysis of cartilage thickness and dGEMRIC index using both a manual and a new automated method compare with the manual 2-D analysis (gold standard)? (2) How does the manual 3-D analysis of regional patterns of dGEMRIC index, cartilage thickness, surface area and volume compare with a new automatic method? (3) What is the interobserver reliability and intraobserver reproducibility of software-assisted manual 3-D and automated 3-D analysis of dGEMRIC indices, thickness, surface, and volume for two readers on two time points?

Methods: In this IRB-approved, retrospective, diagnostic study, we identified the first 25 symptomatic hips (23 patients) who underwent a contrast-enhanced MRI at 3T including a 3-D dGEMRIC sequence for intraarticular pathology assessment due to structural hip deformities.

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Unlabelled: This study developed a well-standardized and reproducible approach for micro-finite element (mFE) and homogenized-FE (hFE) analyses that can accurately predict the distal radius failure load using either mFE or hFE models when using the approaches and parameters developed in this study.

Introduction: Micro-FE analyses based on high-resolution peripheral quantitative CT (HR-pQCT) images are frequently used to predict distal radius failure load. With the introduction of a second-generation HR-pQCT device, however, the default modelling approach no longer provides accurate results.

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Proof of concept: hip joint damage occurs at the zone of femoroacetabular impingement (FAI) in an experimental FAI sheep model.

Osteoarthritis Cartilage

July 2019

Department of Orthopaedic Surgery, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland; Musculoskeletal Research Unit (MSRU), Equine Hospital, Vetsuisse Faculty, University of Zürich, Zürich, Switzerland; Department of Orthopaedic Surgery and Traumatologie, Cantonal Hospital, University of Fribourg, Switzerland.

Objective: In ovine hips chondrolabral damage as seen in cam-type femoroacetabular impingement (FAI) can be induced via an intertrochanteric varus osteotomy. However, it is yet to proven whether the observed cartilage damage is caused by a dynamic cam type impingement. Thus we asked, (1) whether actual cartilage damage observed after FAI induction in ovine hips occurs at the predicted, computed zone of FAI; (2) whether the extent of cartilage damage increases with ambulation time in this animal model?

Design: In this experimental, controlled, comparative study 20 sheep underwent unilateral FAI induction through an intertrochanteric varus osteotomy.

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The formation of skull fractures is an important topic in legal medicine. In particular, the influence of boundary conditions is controversially discussed in the literature. A study focusing solely on this aspect was missing.

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Compressive behaviour of uniaxially aligned individual mineralised collagen fibres at the micro- and nanoscale.

Acta Biomater

April 2019

Institute of Mechanical, Process and Energy Engineering, School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, UK. Electronic address:

The increasing incidence of osteoporotic bone fractures makes fracture risk prediction an important clinical challenge. Computational models can be utilised to facilitate such analyses. However, they critically depend on bone's underlying hierarchical material description.

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Surgeons, scientists and development engineers of surgical devices require phantoms and materials for testing and training purposes. Human or animal bones are the gold standard, but difficult to obtain, prepare and handle. While polyurethane foams can be used as a substitute for trabecular bone, cortical bone substitutes have not been evaluated.

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Background: Individual pelvic tilt and rotation have wide variability that can affect the measurement of cup orientation in anteroposterior (AP) radiographs. The purpose of this study was to analyse the effect of pelvic tilt and rotation on radiographic measurements of cup orientation.

Methods: A total of 53 patients (63 hips) were included in this study.

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Objectives: Recently, more accurate description of the femoral geometry has become of interest to engineers and orthopedic surgeons. However, an appropriate database is lacking. Therefore, the aim of this study is to present morphological parameters and their correlations, which are relevant for medical issues such as impingement after total hip replacement, as well as for implant design and the etiology of hip fractures.

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Mesenchymal stromal cells (MSC) are used in cell therapies, however cellular senescence increases heterogeneity of cell populations and leads to uncertainty in therapies' outcomes. The determination of cellular senescence is time consuming and logistically intensive. Here, we propose the use of endogenous autofluorescence as real-time quantification of cellular senescence in human MSC, based on label-free flow cytometry analysis.

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In the original version of this Article the values in the rightmost column of Table 1 were inadvertently shifted relative to the other columns. This has now been corrected in the PDF and HTML versions of the Article.

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Background: The final strategy for graduates from growth-sparing surgery is challenging. The purpose of this study was to evaluate the radiographic outcome and complications of patients with early onset scoliosis (EOS) who have graduated from vertical expandable prosthetic titanium rib (VEPTR) treatment, either undergoing final fusion surgery or following a nonfusion approach.

Methods: Final treatment for VEPTR graduates was divided in "VEPTR in situ without final fusion," "removal of VEPTR without final fusion," and "removal of VEPTR with instrumented final fusion.

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"Peroperative estimation of bone quality and primary dental implant stability".

J Mech Behav Biomed Mater

April 2019

Institute for Surgical Technology and Biomechanics, University of Bern, Stauffacherstrasse 78, 3014 Bern, Switzerland; Institute for Mechanical, Process and Energy Engineering, Heriot-Watt University, UK EH14 4AS, Edinburgh, United Kingdom.

Objectives: Dental implants are widely used to restore function and appearance. It may be essential to choose the appropriate drilling protocol and implant design in order to optimise primary stability. This could be achieved based on an assessment of the implantation site with respect to bone quality and objective biomechanical descriptors such as stiffness and strength of the bone-implant system.

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