Precision of a Novel Vertebral Motion Analysis System: Preliminary Results

2012 ◽  
Author(s):  
Matthew S. Yeager ◽  
Daniel J. Cook ◽  
Boyle C. Cheng
Keyword(s):  
Muscle Activation ◽  
X Rays ◽  
Current Standard ◽  
Body Depth ◽  
Standard Of Practice ◽  
Static Images ◽  
Magnetic Resonance Imaging Mri ◽  
Analysis System ◽  
High Level ◽  
Relative Change

Imaging modalities such as X-Ray, computerized tomography (CT), magnetic resonance imaging (MRI), and bone scan have all become essential to the evaluation of bone and soft tissue in patients with back pain. All techniques provide valuable static images of the spine, yet lack the capability of providing detailed information about spinal motion. Dynamic end-range x-rays, the standard in assessment of range of motion and vertebral translation, are taken at the patient’s maximum voluntary bending angle in flexion and extension (FE) and/or lateral bending (LB). The current standard of practice is to measure, with ruler and protractor, the relative change between adjacent vertebrae at each bending extreme. The resulting rotational or translational values are then expressed as the intervertebral angle (IVA) or as a percentage of vertebral body depth, respectively. This method, however, is subject to a high level of patient, imaging site, and observer related variability, in the form of uncontrolled bending angles, disparities in equipment and practices, and manual image analysis. An additional limitation of static imagery is the inability to assess motion in the spine as it traverses between end ranges. This information may expose motion abnormalities that occur mid-range that might otherwise be missed by clinicians. Lastly, motion of the spine may present differently in weighted and un-weighted positions. Effects of muscle activation and gravitational forces are not accounted for by current standards.

Top-Ten Tips for Imaging the Brachial Plexus with Ultrasound and MRI

2019 ◽  
Vol 23 (04) ◽  
pp. 405-418 ◽  
Author(s):  
James F. Griffith ◽  
Radhesh Krishna Lalam
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Brachial Plexus ◽  
Muscle Denervation ◽  
Resonance Imaging ◽  
Neural Injury ◽  
Clinical Indications ◽  
Magnetic Resonance Imaging Mri ◽  
High Level ◽  
Extensive Involvement

AbstractWhen it comes to examining the brachial plexus, ultrasound (US) and magnetic resonance imaging (MRI) are complementary investigations. US is well placed for screening most extraforaminal pathologies, whereas MRI is more sensitive and accurate for specific clinical indications. For example, MRI is probably the preferred technique for assessment of trauma because it enables a thorough evaluation of both the intraspinal and extraspinal elements, although US can depict extraforaminal neural injury with a high level of accuracy. Conversely, US is probably the preferred technique for examination of neurologic amyotrophy because a more extensive involvement beyond the brachial plexus is the norm, although MRI is more sensitive than US for evaluating muscle denervation associated with this entity. With this synergy in mind, this review highlights the tips for examining the brachial plexus with US and MRI.

Desmoid tumour of the distal forearm involving the distal radioulnar joint

2020 ◽  
Vol 13 (11) ◽  
pp. e237097
Author(s):  
Apoorv Sehgal ◽  
Pratyush Shahi ◽  
Avijeet Prasad ◽  
Manoj Bhagirathi Mallikarjunaswamy
Keyword(s):  
Distal Radioulnar Joint ◽  
Treatment Modalities ◽  
Desmoid Tumour ◽  
X Rays ◽  
Distal Forearm ◽  
Left Wrist ◽  
Radioulnar Joint ◽  
Magnetic Resonance Imaging Mri ◽  
Epidemiology Investigation

A 32-year-old woman presented with progressive pain and swelling of the left wrist for 6 months. Physical examination revealed a firm, tender, oval swelling over the left wrist. X-rays showed a pressure effect on the distal radius and ulna. Magnetic Resonance Imaging (MRI) revealed a well-defined, asymmetrical, dumbbell-shaped soft-tissue lesion involving the interosseous region of the distal forearm and extending until the distal radioulnar joint (DRUJ). Core needle biopsy confirmed the diagnosis of desmoid tumour. Marginal excision of the tumour was done. At the 2-year follow-up, the patient was doing well and had painless and improved left wrist motion. Desmoid tumour involving the DRUJ has not been previously reported. We, through this case, report new observation and discuss the epidemiology, investigation of choice, treatment modalities, and the need for a regular follow-up for appendicular desmoid tumours.

scholarly journals Complete heart block in cardiac sarcoidosis reversed by corticosteroid therapy: time course of resolution

2021 ◽  
Vol 14 (3) ◽  
pp. e240834
Author(s):  
Anna Tomdio ◽  
Huzaefah Syed ◽  
Kenneth Ellenbogen ◽  
Jordana Kron
Keyword(s):  
Heart Block ◽  
Time Course ◽  
Cardiac Sarcoidosis ◽  
Complete Heart Block ◽  
Positron Emission ◽  
Av Conduction ◽  
Magnetic Resonance Imaging Mri ◽  
High Level ◽  
Active Inflammation ◽  
Lateral Walls

A 53-year-old man was admitted for recurrent syncope and found to have complete heart block (CHB). Cardiac magnetic resonance imaging MRI) showed extensive patchy late gadolinium enhancement in the apical and lateral walls, consistent with cardiac sarcoidosis (CS) but no scar in the septum. A fluorodeoxyglucose (FDG)–positron emission tomography showed FDG uptake in the septum and basal lateral walls. Imaging suggested active inflammation in the septum affecting atrioventricular (AV) conduction but no irreversible fibrosis. Diagnosis of isolated CS requires a high level of suspicion and multidisciplinary teamwork involving heart failure specialists, electrophysiologists and rheumatologists. After specialist and patient discussion, treatment of the disease was initiated with prednisone 40 mg daily, 11 months after presenting with CHB. Three weeks later, ECG with pacing inhibited showed second-degree AV block Mobitz type II and 4 weeks later, AV conduction recovery. This highlights the importance of immediate therapy in reversing AV conduction abnormalities in CS.

Alchemy: Distributed financial quantitative analysis system with high‐level programming model

2021 ◽  
Author(s):  
Rong Gu ◽  
Zhixiang Zhang ◽  
Zhihao Xu ◽  
Zhaokang Wang ◽  
Kai Zhang ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Programming Model ◽  
Analysis System ◽  
High Level

Design for Assembly Evaluation of Orientation Difficulty Features

1992 ◽  
Author(s):  
Robert H. Sturges ◽  
Jui-Te Yang
Keyword(s):  
Geometric Modeling ◽  
Boundary Representation ◽  
Design For Assembly ◽  
Assembly Process ◽  
Assembly Evaluation ◽  
Index Of Difficulty ◽  
Analysis System ◽  
Time Required ◽  
High Level ◽  
Geometric Modeling System

Abstract In support of the effort to bring downstream issues to the attention of the designer as parts take shape, an analysis system is being built to extract certain features relevant to the assembly process, such as the dimension, shape, and symmetry of an object. These features can be applied to a model during the downstream process to evaluate handling and assemblability. In this paper, we will focus on the acquisition phase of the assembly process and employ a Design for Assembly (DFA) evaluation to quantify factors in this process. The capabilities of a non-homogeneous, non-manifold boundary representation geometric modeling system are used with an Index of Difficulty (ID) that represents the dexterity and time required to assemble a product. A series of algorithms based on the high-level abstractions of loop and link are developed to extract features that are difficult to orient, which is one of the DFA criteria. Examples for testing the robustness of the algorithms are given. Problems related to nearly symmetric outlines are also discussed.

Crankshaft Stress Analysis—Combination of Finite Element and Classical Analysis Techniques

1990 ◽  
Vol 112 (3) ◽  
pp. 268-275 ◽  
Author(s):  
A. R. Heath ◽  
P. M. McNamara
Keyword(s):  
Stress Analysis ◽  
Concept Design ◽  
Low Friction ◽  
Failure Investigation ◽  
Engine Design ◽  
Computer Based ◽  
Analysis System ◽  
High Level ◽  
Engine Components ◽  
Oil Films

The conflicting legislative and customer pressures on engine design, for example, combining low friction and a high level of refinement, require sophisticated tools if competitive designs are to be realized. This is particularly true of crankshafts, probably the most analyzed of all engine components. This paper describes the hierarchy of methods used for crankshaft stress analysis with case studies. A computer-based analysis system is described that combines FE and classical methods to allow optimized designs to be produced efficiently. At the lowest level simplified classical techniques are integrated into the CAD-based design process. These methods give the rapid feedback necessary to perform concept design iterations. Various levels of FE analysis are available to carry out more detailed analyses of the crankshaft. The FE studies may feed information to or take information from the classical methods. At the highest level a method for including the load sharing effects of the flexible crankshaft within a flexible block interconnected by nonlinear oil films is described. This method includes the FE modeling of the complete crankshaft and the consideration of its stress field throughout an engine cycle. Fatigue assessment is performed to calculate the distribution of fatigue safety factor on the surface of the crankshaft. This level of analysis can be used for failure investigation, or detailed design optimization and verification. The method is compatible with those used for vibration and oil film analysis.

Biomedical Image Processing Overview

2016 ◽  
pp. 1-12 ◽  
Author(s):  
Monia Mannai Mannai ◽  
Wahiba Ben Abdessalem Karâa
Keyword(s):  
Image Processing ◽  
Medical Imaging ◽  
Medical Image Processing ◽  
Main Process ◽  
Nuclear Medicine Imaging ◽  
Biomedical Image Processing ◽  
Biomedical Image ◽  
X Ray Computed ◽  
Magnetic Resonance Imaging Mri ◽  
High Level

Over the years, there are different sorts of medical imaging have been developed. Where the most known are: X-ray, computed tomography (CT), nuclear medicine imaging (PET, SPECT), ultrasound and magnetic resonance imaging (MRI), each one has its different utilities. Various studies in biomedical informatics present a process to analyze images for extracting the hidden information which can be used after that. Image analysis combines several fields that are classified into two categories; the process of low-level, that requires very little information about the content image and the process of high-level, which may need information about the image content. The topic of this chapter is to introduce the different techniques for medical image processing and to present many research studies in this domain. It includes four stages, firstly, we introduce the most important medical imaging modalities and secondly, we outline the main process of biomedical image.

Muscle Activation in the Main Muscle Groups of the Lower Limbs in High-Level Dancesport Athletes

2018 ◽  
Vol 33 (4) ◽  
pp. 231-237
Author(s):  
Encarnación Liébana ◽  
Cristina Monleón ◽  
Raquel Morales ◽  
Carlos Pablos ◽  
Consuelo Moratal ◽  
...  
Keyword(s):  
Tibialis Anterior ◽  
Muscle Activation ◽  
Rectus Femoris ◽  
Biceps Femoris ◽  
Lower Limbs ◽  
Gastrocnemius Medialis ◽  
Leg Muscles ◽  
Relative Activation ◽  
Muscle Groups ◽  
High Level

Dancers are subjected to high-intensity workouts when they practice dancesport, and according to the literature, they are prone to injury, primarily of the lower limbs. The purpose of this study was to determine whether differences exist in relative activation amplitudes for dancers involved in dancesport due to muscle, gender, and type of dance. Measurements were carried out using surface electromyography equipment during the choreography of a performance in the following leg muscles: rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius medialis. Eight couples of active dancesport athletes (aged 20.50±2.75 yrs) were analyzed. Significant gender differences were found in rumba in the tibialis anterior (p≤0.05) and gastrocnemius medialis (p≤0.05). Based on the different activations, it is possible to establish possible mechanisms of injury, as well as tools for preventing injuries and improving sports performance.

scholarly journals A unified accretion-ejection paradigm for black hole X-ray binaries

2019 ◽  
Vol 626 ◽  
pp. A115 ◽  
Author(s):  
G. Marcel ◽  
J. Ferreira ◽  
M. Clavel ◽  
P.-O. Petrucci ◽  
J. Malzac ◽  
...  
Keyword(s):  
Radio Emission ◽  
Accretion Disk ◽  
Ad Hoc ◽  
Emission Model ◽  
X Rays ◽  
Temperature Plasma ◽  
X Ray ◽  
Fitting Procedure ◽  
High Level ◽  
X Ray Binaries

Context. Transient X-ray binaries (XrB) exhibit very different spectral shapes during their evolution. In luminosity-color diagrams, their behavior in X-rays forms q-shaped cycles that remain unexplained. In Paper I, we proposed a framework where the innermost regions of the accretion disk evolve as a response to variations imposed in the outer regions. These variations lead not only to modifications of the inner disk accretion rate ṁin, but also to the evolution of the transition radius rJ between two disk regions. The outermost region is a standard accretion disk (SAD), whereas the innermost region is a jet-emitting disk (JED) where all the disk angular momentum is carried away vertically by two self-confined jets. Aims. In the previous papers of this series, it has been shown that such a JED–SAD disk configuration could reproduce the typical spectral (radio and X-rays) properties of the five canonical XrB states. The aim of this paper is now to replicate all X-ray spectra and radio emission observed during the 2010–2011 outburst of the archetypal object GX 339-4. Methods. We used the two-temperature plasma code presented in two previous papers (Papers II and III) and designed an automatic ad hoc fitting procedure that for any given date calculates the required disk parameters (ṁin,rJ) that fit the observed X-ray spectrum best. We used X-ray data in the 3–40 keV (RXTE/PCA) spread over 438 days of the outburst, together with 35 radio observations at 9 GHz (ATCA) dispersed within the same cycle. Results. We obtain the time distributions of ṁin(t) and rJ(t) that uniquely reproduce the X-ray luminosity and the spectral shape of the whole cycle. In the classical self-absorbed jet synchrotron emission model, the JED–SAD configuration also reproduces the radio properties very satisfactorily, in particular, the switch-off and -on events and the radio-X-ray correlation. Although the model is simplistic and some parts of the evolution still need to be refined, this is to our knowledge the first time that an outburst cycle is reproduced with such a high level of detail. Conclusions. Within the JED–SAD framework, radio and X-rays are so intimately linked that radio emission can be used to constrain the underlying disk configuration, in particular, during faint hard states. If this result is confirmed using other outbursts from GX 339-4 or other X-ray binaries, then radio could be indeed used as another means to indirectly probe disk physics.

scholarly journals Traumatic Obturator Hip Dislocation with Marginal Femoral Head Fracture in a 15-Year-Old Adolescent: A High-Energy Trauma—A Case Report and a Review of the Literature

2018 ◽  
Vol 2018 ◽  
pp. 1-4
Author(s):  
Yoann Durand ◽  
Clémence Bruyère ◽  
Marco Saglini ◽  
Aurélien Michel-Traverso
Keyword(s):  
Femoral Head ◽  
Hip Dislocation ◽  
High Energy ◽  
Hip Pain ◽  
X Rays ◽  
Hip Function ◽  
One Year ◽  
High Level ◽  
Joint Limitation

We report the case of a 15-year-old boy brought to the emergency department after a bike accident, complaining of an isolated left hip pain. The X-rays showed an obturator hip dislocation treated by closed reduction under general anaesthesia, followed by 6 weeks of discharge. The follow-up MRI performed 6 weeks after the trauma showed an avascular femoral head necrosis, for which we performed multiple retrograde femoral head drilling, completed by the injection of autologue stem cells from the iliaq crest. One year later, the patient has no hip pain, no joint limitation, and can practice BMX at a high level again. The purpose of this report is to make the physicians aware of this rare problem that may be damaging for hip function, especially in young people.

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