scholarly journals In Vivo Deformation and Strain Measurements in Human Bone Using Digital Volume Correlation (DVC) and 3T Clinical MRI

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5354
Author(s):  
Saman Tavana ◽  
Jeffrey N. Clark ◽  
Nicolas Newell ◽  
James D. Calder ◽  
Ulrich Hansen
Keyword(s):  
Spatial Resolution ◽  
Injury Risk ◽  
Relevant Information ◽  
Invasive Technique ◽  
Digital Volume Correlation ◽  
Non Invasive ◽  
Bone Strains ◽  
Clinical Mri ◽  
Optimal Settings

Strains within bone play an important role in the remodelling process and the mechanisms of fracture. The ability to assess these strains in vivo can provide clinically relevant information regarding bone health, injury risk, and can also be used to optimise treatments. In vivo bone strains have been investigated using multiple experimental techniques, but none have quantified 3D strains using non-invasive techniques. Digital volume correlation based on clinical MRI (DVC-MRI) is a non-invasive technique that has the potential to achieve this. However, before it can be implemented, uncertainties associated with the measurements must be quantified. Here, DVC-MRI was evaluated to assess its potential to measure in vivo strains in the talus. A zero-strain test (two repeated unloaded scans) was conducted using three MRI sequences, and three DVC approaches to quantify errors and to establish optimal settings. With optimal settings, strains could be measured with a precision of 200 με and accuracy of 480 με for a spatial resolution of 7.5 mm, and a precision of 133 με and accuracy of 251 με for a spatial resolution of 10 mm. These results demonstrate that this technique has the potential to measure relevant levels of in vivo bone strain and to be used for a range of clinical applications.

scholarly journals Optical coherence tomography imaging of oral mucosa bullous diseases: a preliminary study

2020 ◽  
Vol 49 (2) ◽  
pp. 20190071
Author(s):  
Dario Di Stasio ◽  
Dorina Lauritano ◽  
Francesca Loffredo ◽  
Enrica Gentile ◽  
Fedora Della Vella ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Oral Mucosa ◽  
Statistical Power ◽  
Pemphigus Vulgaris ◽  
Invasive Technique ◽  
Optical Coherence ◽  
Non Invasive ◽  
Bullous Diseases ◽  
Subepithelial Layer

Objectives: Optical coherence tomography (OCT) is a non-invasive technique based on optical imaging with a micrometre resolution. The purpose of this study is to investigate the potential role of OCT in evaluating oral mucosa bullous diseases. Methods: two patients with bullous pemphigoid (BP) and one patient with pemphigus vulgaris (PV) were examined and images of their oral lesions were performed using OCT. Results: In OCT images, the BP blister has a clearly different morphology from the PV one compared to the blistering level. Conclusion: This exploratory study suggests that the OCT is able to distinguish epithelial and subepithelial layer in vivo images of healthy oral mucosa from those with bullous diseases, assisting the clinicians in differential diagnosis.The presented data are in accordance with the scientific literature, although a wider pool of cases is needed to increase statistical power. Histological examination and immunofluorescence methods remain the gold standard for the diagnosis of oral bullous diseases. In this context, the OCT can provide the clinician with a valuable aid both as an additional diagnostic tool and in the follow up of the disease.

scholarly journals Confocal Raman spectroscopy: Evaluation of a non-invasive technique for the detection of topically applied ketorolac tromethamine in vitro and in vivo

2019 ◽  
Vol 570 ◽  
pp. 118641 ◽  
Author(s):  
Christian J.F. Bertens ◽  
Shuo Zhang ◽  
Roel J. Erckens ◽  
Frank J.H.M. van den Biggelaar ◽  
Tos T.J.M. Berendschot ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Invasive Technique ◽  
Ketorolac Tromethamine ◽  
Confocal Raman Spectroscopy ◽  
Non Invasive ◽  
Confocal Raman

scholarly journals In vivo contactless brain stimulation via non-invasive and targeted delivery of magnetoelectric nanoparticles

2020 ◽  
Author(s):  
Tyler Nguyen ◽  
Jianhua Gao ◽  
Ping Wang ◽  
Abhignyan Nagesetti ◽  
Peter Andrews ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Brain Stimulation ◽  
Targeted Delivery ◽  
Brain Region ◽  
Magnetic Field Gradient ◽  
Latency Period ◽  
Global Network ◽  
Invasive Technique ◽  
Non Invasive

AbstractNon-invasive brain stimulation is valuable for studying neural circuits and treating various neurological disorders in humans. However, the current technologies usually have low spatial and temporal precision and poor brain penetration, which greatly limit their application. A new class of nanoparticles known as magneto-electric nanoparticles (MENs) can be navigated to a targeted brain region with a magnetic field and is highly efficient in converting an externally applied magnetic wave into local electric fields for neuronal activity modulation. Here we developed a new method to fabricate MENs of CoFe2O4-BaTiO3 core-shell structure that had excellent magneto-electrical coupling properties. Using calcium imaging of organotypic and acute cortical slices from GCaMP6s transgenic mice, we demonstrated their efficacy in reliably evoking neuronal responses with a short latency period. For in vivo non-invasive delivery of MENs to brain, fluorescently labeled MENs were intravenously injected and guided to pass through the blood brain barrier to a targeted brain region by applying a magnetic field gradient. A magnetic field (∼450 Oe at 10 Hz) applied to mouse brain was able to reliably evoke cortical activities, as revealed by in vivo two-photon and mesoscopic imaging of calcium signals at both cellular and global network levels. The effect was further confirmed by the increased number of c-Fos expressing cells after stimulation. Neither brain delivery of MENs nor the subsequent magnetic stimulation caused any significant increases in the numbers of GFAP and IBA1 positive astrocytes and microglia in the brain. This study demonstrates the feasibility of using MENs as a novel efficient and non-invasive technique of contactless deep brain stimulation that may have great potential for translation.

scholarly journals Deep Learning for Non-Invasive Cortical Potential Imaging

2020 ◽  
Author(s):  
Alexandra Razorenova ◽  
Nikolay Yavich ◽  
Mikhail Malovichko ◽  
Maxim Fedorov ◽  
Nikolay Koshev ◽  
...  
Keyword(s):  
Inverse Problem ◽  
Deep Learning ◽  
Electric Fields ◽  
Spatial Resolution ◽  
Brain Activity ◽  
Invasive Technique ◽  
Problem Solver ◽  
Deep Convolutional Neural Networks ◽  
Non Invasive ◽  
Cortical Potential Imaging

AbstractElectroencephalography (EEG) is a well-established non-invasive technique to measure the brain activity, albeit with a limited spatial resolution. Variations in electric conductivity between different tissues distort the electric fields generated by cortical sources, resulting in smeared potential measurements on the scalp. One needs to solve an ill-posed inverse problem to recover the original neural activity. In this article, we present a generic method of recovering the cortical potentials from the EEG measurement by introducing a new inverse-problem solver based on deep Convolutional Neural Networks (CNN) in paired (U-Net) and unpaired (DualGAN) configurations. The solvers were trained on synthetic EEG-ECoG pairs that were generated using a head conductivity model computed using the Finite Element Method (FEM). These solvers are the first of their kind, that provide robust translation of EEG data to the cortex surface using deep learning. Providing a fast and accurate interpretation of the tracked EEG signal, our approach promises a boost to the spatial resolution of the future EEG devices.

Extracranial Carotid Artery Disease Assessed By Indium-111 Labelled Platelets In Man

1981 ◽  
Author(s):  
M Goldman ◽  
D Simpson ◽  
R J Hawker ◽  
Z Drolc ◽  
C N McCollum
Keyword(s):  
Gamma Camera ◽  
Ex Vivo ◽  
Carotid Artery Disease ◽  
Objective Assessment ◽  
Diagnostic Methods ◽  
Invasive Technique ◽  
Platelet Activity ◽  
Transient Ischaemic Attacks ◽  
Non Invasive

Platelet microemboli have been implicated in the aetiology of transient ischaemic attacks and strokes. Current non-invasive diagnostic methods are restricted to assessing blood flow. Arteriography may demonstrate non-occluding atheromatous ulcers but carries a significant morbidity.111-In labelled platelets and gamma camera imaging of diseased carotid vessels have therefore been evaluated.Eight patients proceeding to unilateral carotid endarterectomy received an injection of autologous platelets labelled with 111-In-oxine 48 hours preoperatively. Gamma camera images were taken at 4 and 24 hours. Operative endarterectomy specimens were collected and gamma emissions were measured.The scintigraphic images were independently assessed by two observers. Nine abnormal vessels were identified by platelet accumulation. In 5 cases the observers combined assessment was in complete accord with previous bilateral angiography. Individually each observer identified the symptomatic side in 6 patients. Activity in the endarterectomy specimens measured ex vivo varied from 1.22-84.5 times greater than background activity. The ratio of specimen activity to 5 ml blood samples simultaneously taken varied from 0.017 to 0.360 (mean 0.089).This non-invasive technique allows localisation of platelet activity in the extracranial cerebral circulation. Objective assessment in vivo is hindered by the relatively small amount of activity on the diseased vessels by comparison with circulating blood activity.

scholarly journals Dynamics of Central Remyelination and Treatment Evolution in a Model of Multiple Sclerosis with Optic Coherence Tomography

2021 ◽  
Vol 22 (5) ◽  
pp. 2440
Author(s):  
Rocío Benítez-Fernández ◽  
Carolina Melero-Jerez ◽  
Carmen Gil ◽  
Enrique J. de la Rosa ◽  
Ana Martínez ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Spinal Cord ◽  
Central Nervous System ◽  
Invasive Technique ◽  
Optic Coherence Tomography ◽  
Non Invasive ◽  
Disease Modifying ◽  
Orally Bioavailable ◽  
Ms Therapy

The need for remyelinating drugs is essential for healing disabling diseases such as multiple sclerosis (MS). One of the reasons for the lack of this class of therapies is the impossibility to monitor remyelination in vivo, which is of utmost importance to perform effective clinical trials. Here, we show how optical coherence tomography (OCT), a cheap and non-invasive technique commonly used in ophthalmology, may be used to assess remyelination in vivo in MS patients. Our pioneer approach validates OCT as a technique to study remyelination of the optic nerve and reflects what is occurring in non-accessible central nervous system (CNS) structures, like the spinal cord. In this study we used the orally bioavailable small molecule VP3.15, confirming its therapeutical potential as a neuroprotective, anti-inflammatory, and probably remyelinating drug for MS. Altogether, our results confirm the usefulness of OCT to monitor the efficacy of remyelinating therapies in vivo and underscore the relevance of VP3.15 as a potential disease modifying drug for MS therapy.

Dual energy X-ray absorptiometry is a valid tool for assessing in vivo body composition of broilers

2019 ◽  
Vol 59 (5) ◽  
pp. 993 ◽  
Author(s):  
Camila Angelica Gonçalves ◽  
Nilva Kazue Sakomura ◽  
Edney Pereira da Silva ◽  
Silvana Martinez Baraldi Artoni ◽  
Rafael Massami Suzuki ◽  
...  
Keyword(s):  
Body Composition ◽  
Crude Protein ◽  
Dual Energy ◽  
The Body ◽  
Invasive Technique ◽  
Composition Analysis ◽  
Regression Equations ◽  
X Ray ◽  
Non Invasive

The use of non-invasive techniques to estimate body composition in animals in vivo conforms to the desire to improve the welfare of animals during research and also has the potential to advance scientific research. The purpose of the present study was to determine a predictive equation of the dual energy X-ray absorptiometry (DXA) method for broilers by comparing the measurement of body composition using DXA with that by chemical analysis. In total, 720 day-old Cobb500 broilers were distributed into a split-plot arrangement 3 (crude protein concentrations of diets) × 2 (genders) × 2 (methods of chemical body evaluation), with six replications of 20 birds each. To promote the modification of the body composition of broilers, diets varied in the crude protein concentration, which was 70%, 100% and 130% of the required. Two hundred and sixteen birds in different ages were evaluated by its bodyweight, lean, fat and ash contents. The data were submitted to ANOVA and it was demonstrated that the dietary crude protein levels applied allowed a greater variation of the body composition of the birds. Also, the results indicated that the DXA method did not predict fat mass, lean mass or bone mineral content as well as did chemical composition analysis, resulting in the need to develop regression equations for improving the in vivo prediction of these chemical components. The regression equations developed here enable the feather-free body composition of individual broilers to be directly estimated throughout growth using the DXA non-invasive technique.

scholarly journals Reversible membrane reorganizations during photosynthesis in vivo: revealed by small-angle neutron scattering

2011 ◽  
Vol 436 (2) ◽  
pp. 225-230 ◽  
Author(s):  
Gergely Nagy ◽  
Dorthe Posselt ◽  
László Kovács ◽  
Jens K. Holm ◽  
Milán Szabó ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Higher Plants ◽  
Thylakoid Membranes ◽  
Invasive Technique ◽  
Time Resolved ◽  
Functional Changes ◽  
Non Invasive

In the present study, we determined characteristic repeat distances of the photosynthetic membranes in living cyanobacterial and eukaryotic algal cells, and in intact thylakoid membranes isolated from higher plants with time-resolved small-angle neutron scattering. This non-invasive technique reveals light-induced reversible reorganizations in the seconds-to-minutes time scale, which appear to be associated with functional changes in vivo.

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