scholarly journals Stability of Liver Radiomics across Different 3D ROI Sizes—An MRI In Vivo Study

Tomography ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 866-876
Author(s):  
Laura J. Jensen ◽  
Damon Kim ◽  
Thomas Elgeti ◽  
Ingo G. Steffen ◽  
Bernd Hamm ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Size Variation ◽  
Correlation Coefficients ◽  
Liver Parenchyma ◽  
Systematic Difference ◽  
3 Tesla ◽  
Concordance Correlation ◽  
The Stability ◽  
Different Diameters

We aimed to evaluate the stability of radiomic features in the liver of healthy individuals across different three-dimensional regions of interest (3D ROI) sizes in T1-weighted (T1w) and T2-weighted (T2w) images from different MR scanners. We retrospectively included 66 examinations of patients without known diseases or pathological imaging findings acquired on three MRI scanners (3 Tesla I: 25 patients, 3 Tesla II: 19 patients, 1.5 Tesla: 22 patients). 3D ROIs of different diameters (10, 20, 30 mm) were drawn on T1w GRE and T2w TSE images into the liver parenchyma (segment V–VIII). We extracted 93 radiomic features from the different ROIs and tested features for significant differences with the Mann–Whitney-U (MWU)-test. The MWU-test revealed significant differences for most second- and higher-order features, indicating a systematic difference dependent on the ROI size. The features mean, median, root mean squared (RMS), 10th percentile, and 90th percentile were not significantly different. We also assessed feature robustness to ROI size variation with overall concordance correlation coefficients (OCCCs). OCCCs across the different ROI-sizes for mean, median, and RMS were excellent (>0.90) in both sequences on all three scanners. These features, therefore, seem robust to ROI-size variation and suitable for radiomic studies of liver MRI.

scholarly journals Stability of Radiomic Features across Different Region of Interest Sizes—A CT and MR Phantom Study

Tomography ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 238-252
Author(s):  
Laura J. Jensen ◽  
Damon Kim ◽  
Thomas Elgeti ◽  
Ingo G. Steffen ◽  
Bernd Hamm ◽  
...  
Keyword(s):  
Excellent Agreement ◽  
Correlation Coefficients ◽  
Region Of Interest ◽  
Systematic Difference ◽  
Gradient Echo ◽  
Mr Images ◽  
Concordance Correlation ◽  
Disease Entities ◽  
Different Diameters ◽  
Turbo Inversion Recovery Magnitude

We aimed to evaluate radiomic features’ stability across different region of interest (ROI) sizes in CT and MR images. We chose a phantom with a homogenous internal structure so no differences for a feature extracted from ROIs of different sizes would be expected. For this, we scanned a plastic cup filled with sodium chloride solution ten times in CT and per MR sequence (T1-weighted-gradient-echo and T2-weighted-turbo-inversion-recovery-magnitude). We placed sphere-shaped ROIs of different diameters (4, 8, and 16 mm, and 4, 8, and 16 pixels) into the phantom’s center. Features were extracted using PyRadiomics. We assessed feature stability across ROI sizes with overall concordance correlation coefficients (OCCCs). Differences were tested for significance with the Mann–Whitney U-test. Of 93 features, 87 T1w-derived, 87 TIRM-derived, and 70 CT-derived features were significantly different between ROI sizes. Among MR-derived features, OCCCs showed excellent (>0.90) agreement for mean, median, and root mean squared for ROI sizes between 4 and 16 mm and pixels. We further observed excellent agreement for 10th and 90th percentile in T1w and 10th percentile in T2w TIRM images. There was no excellent agreement among the OCCCs of CT-derived features. In summary, many features indicated significant differences and only few showed excellent agreement across varying ROI sizes, although we examined a homogenous phantom. Since we considered a small phantom in an experimental setting, further studies to investigate this size effect would be necessary for a generalization. Nevertheless, we believe knowledge about this effect is crucial in interpreting radiomics studies, as features that supposedly discriminate disease entities may only indicate a systematic difference in ROI size.

scholarly journals Nanoparticles Mediated Protein Stability in Comparison with Osmolytes: in vivo Approach

2021 ◽  
Vol 33 (6) ◽  
pp. 1433-1438
Author(s):  
R. Verma ◽  
N. Singh ◽  
P. Chaudhuri (Chattopadhyay)
Keyword(s):  
Gold Nanoparticles ◽  
Dihydrofolate Reductase ◽  
Three Dimensional ◽  
Cellular Level ◽  
Dimensional Structure ◽  
Important Group ◽  
Unfolded State ◽  
The Status ◽  
The Stability

The native three-dimensional structure of protein is quite unstable under critical destabilizing conditions. In order to enhance the stability and activity for a proper folded environment of a protein, many stabilizing materials are added such as nanoparticles and osmolytes to an unfolded state of protein. Osmolytes are the important group of molecules which are engaged by the cell as an adaption in the severe conditions. In this communication, a comparative in vivo study is reported for imparting the status of stability and folding ability of zebrafish dihydrofolate reductase (zDHFR) protein with gold nanoparticles and various osmolytes (glycerol, glucose and betain). Present observations revealed that the interaction of gold nanoparticles (AuNPs) with bacteria at the cellular level helps in maintaining the stability of protein more effectively than osmolytes which could be used for many biological and pharmacological approaches although glycerol as an osmolyte also stabilizes the protein at a significant level.

scholarly journals UTE-T2⁎Analysis of Diseased and Healthy Achilles Tendons and Correlation with Clinical Score: An In Vivo Preliminary Study

2017 ◽  
Vol 2017 ◽  
pp. 1-5 ◽  
Author(s):  
Yang Qiao ◽  
Hong-Yue Tao ◽  
Kui Ma ◽  
Zi-Ying Wu ◽  
Jian-Xun Qu ◽  
...  
Keyword(s):  
Achilles Tendon ◽  
Pearson Correlation ◽  
Achilles Tendon Rupture ◽  
Three Dimensional ◽  
Correlation Coefficients ◽  
Clinical Score ◽  
Ultrashort Echo Time ◽  
Clinical Scores ◽  
American Orthopaedic

Objective. To compareT2⁎value of healthy and diseased Achilles tendons (AT) with a recently introduced three-dimensional ultrashort echo time (3D-UTE) sequence and analyze the correlation betweenT2⁎value and clinical scores.Methods. Ten patients with symptomatic Achilles tendon and ten healthy volunteers were investigated with 3D-UTE sequence on a 3T magnetic resonance (MR) scanner.T2⁎values of four regions in Achilles tendons were calculated. The clinical outcomes of patients were evaluated according to the American Orthopaedic Foot and Ankle Society (AOFAS) score and Achilles Tendon Rupture Score (ATRS). An independent samplet-test was used to compare the differences ofT2⁎value and clinical scores between two groups. The Pearson correlation coefficient between clinical scores andT2⁎values was assessed.Results. TheT2⁎values of Achilles tendon were statistically significantly different between patients and volunteers. The Pearson correlation coefficients betweenT2⁎and AOFAS or ATRS scores of patients werer=-0.733andr=-0.634, respectively.Conclusion. The variability ofT2⁎in healthy and pathologic AT can be quantified by UTE-T2⁎.T2⁎may be a promising marker to detect and diagnose AT tendinopathy. UTE-T2⁎could give a precise guidance to clinical outcome.

Reliability of Achilles Tendon Moment Arm Measured In Vivo Using Freehand Three-Dimensional Ultrasound

2017 ◽  
Vol 33 (4) ◽  
pp. 300-304 ◽  
Author(s):  
Steven J. Obst ◽  
Lee Barber ◽  
Ashton Miller ◽  
Rod S. Barrett
Keyword(s):  
Achilles Tendon ◽  
Plantar Flexion ◽  
Three Dimensional ◽  
Correlation Coefficients ◽  
Lateral Malleolus ◽  
Medial Malleolus ◽  
Minimal Detectable Change ◽  
Ultrasound Images ◽  
Moment Arm

This study investigated reliability of freehand three-dimensional ultrasound (3DUS) measurement of in vivo human Achilles tendon (AT) moment arm. Sixteen healthy adults were scanned on 2 separate occasions by a single investigator. 3DUS scans were performed over the free AT, medial malleolus, and lateral malleolus with the ankle passively positioned in maximal dorsiflexion, mid dorsiflexion, neutral, mid plantar flexion and maximal plantar flexion. 3D reconstructions of the AT, medial malleolus, and lateral malleolus were created from manual segmentation of the ultrasound images and used to geometrically determine the AT moment arm using both a straight (straight ATMA) and curved (curved ATMA) tendon line-of-action. Both methods were reliable within- and between-session (intra-class correlation coefficients > 0.92; coefficient of variation < 2.5 %) and revealed that AT moment arm increased by ∼ 7 mm from maximal dorsiflexion (∼ 41mm) to maximal plantar flexion (∼ 48 mm). Failing to account for tendon curvature led to a small overestimation (< 2 mm) of AT moment arm that was most pronounced in ankle plantar flexion, but was less than the minimal detectable change of the method and could be disregarded.

scholarly journals Intramuscular Fatty Acids in Meat Could Predict Enteric Methane Production by Fattening Lambs

Animals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 2053
Author(s):  
Francisco Requena Domenech ◽  
Pilar Gómez-Cortés ◽  
Silvia Martínez-Miró ◽  
Miguel Ángel de la Fuente ◽  
Fuensanta Hernández ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Environmental Sustainability ◽  
Vaccenic Acid ◽  
Correlation Coefficients ◽  
Prediction Errors ◽  
Statistical Regression ◽  
Concordance Correlation ◽  
Indicator Method ◽  
Ch4 Production

Methane (CH4) emissions pose a serious problem for the environmental sustainability of ruminant production. The aim of the present study was to explore the usefulness of the intramuscular fatty acid (FA) profile to estimate CH4 production of lambs fattened under intensive feeding systems. A statistical regression analysis of intramuscular FA derived from ruminal metabolism was carried out to assess the best predictive model of CH4 production (g/d) in lambs fed with different diets. CH4 was calculated with three distinct equations based on organic matter digestibility (OMD) at maintenance feeding levels. The OMD of the experimental diets was determined in an in vivo digestibility trial by means of the indicator method. Regression models were obtained by stepwise regression analysis. The three optimized models showed high adjusted coefficients of determination (R2adj = 0.74–0.93) and concordance correlation coefficients (CCC = 0.89–0.98), as well as small root mean square prediction errors (RMSPE = 0.29–0.40 g/d). The best single predictor was vaccenic acid (trans-11 C18:1), a bioactive FA that is formed in the rumen to a different extent depending on dietary composition. Based on our data and further published lamb research, we propose a novel regression model for CH4 production with excellent outcomes: CH4 (g/d) = −1.98 (±1.284)–0.87 (±0.231) × trans-11 C18:1 + 0.79 (±0.045) × BW (R2adj = 0.97; RMSPE = 0.76 g/d; CCC = 0.98). In conclusion, these results indicate that specific intramuscular FA and average BW during fattening could be useful to predict CH4 production of lambs fed high concentrate diets.

scholarly journals An experimental study of the motion of a viscous liquid contained between two coaxial cylinders

1928 ◽  
Vol 117 (777) ◽  
pp. 388-407 ◽  
Keyword(s):  
Viscous Liquid ◽  
Three Dimensional ◽  
Critical Value ◽  
Limited Range ◽  
Axial Plane ◽  
Stream Line ◽  
Coaxial Cylinders ◽  
Wide Range ◽  
The Stability ◽  
Different Diameters

The stability of a viscous liquid contained between two coaxial cylinders which are capable of independent rotation has been investigated by G. I. Taylor. At low speeds of rotation the motion of the liquid is two-dimensional, each particle of liquid rotating in a circle concentric with the cylinders. This type of motion is possible whether the cylinders rotate in the same or in opposite directions, and is stable for velocities of the inner cylinder not exceeding a certain critical value. At the critical speed the laminar motion is succeeded by a three-dimensional motion, such that the circulation of the liquid is confined to a scries of annular compartments, one above the other. When both cylinders rotate in the same direction, the height of each compartment equals the distance between the cylinders, and the motion in an axial plane appears to consist of a series of vortices in square compartments, adjacent vortices rotating in opposite directions. For cylinders rotating in opposite directions there are, at a given horizontal level, two annular compartments side by side and concentric with the cylinders. In this case, the circulation in an axial plane appears to consist of two series of vortices, adjacent vortices both vertically and horizontally rotating in opposite directions. By using coloured liquid filaments to follow the motion, Taylor verified experimentally, within a limited range, the expression for the critical velocity at which the stream-line motion becomes unstable and certain other points. The apparatus used was large and robust, the length of the cylinders being 90 cm., and it was unsuitable for investigating the motion under varying conditions, such as with inner cylinders of different diameters and with liquids giving a wide range in viscosity.

scholarly journals Acoustic trapping of microbubbles in complex environments and controlled payload release

2020 ◽  
Vol 117 (27) ◽  
pp. 15490-15496 ◽  
Author(s):  
Diego Baresch ◽  
Valeria Garbin
Keyword(s):  
Acoustic Waves ◽  
Three Dimensional ◽  
Absolute Calibration ◽  
Complex Environments ◽  
Single Beam ◽  
Trapping Force ◽  
3D Positioning ◽  
The Stability ◽  
Low Amplitude

Contactless manipulation of microparticles using acoustic waves holds promise for applications ranging from cell sorting to three-dimensional (3D) printing and tissue engineering. However, the unique potential of acoustic trapping to be applied in biomedical settings remains largely untapped. In particular, the main advantage of acoustic trapping over optical trapping, namely the ability of sound to propagate through thick and opaque media, has not yet been exploited in full. Here we demonstrate experimentally the use of the recently developed technique of single-beam acoustical tweezers to trap microbubbles, an important class of biomedically relevant microparticles. We show that the region of vanishing pressure of a propagating vortex beam can confine a microbubble by forcing low-amplitude, nonspherical, shape oscillations, enabling its full 3D positioning. Our interpretation is validated by the absolute calibration of the acoustic trapping force and the direct spatial mapping of isolated bubble echos, for which both find excellent agreement with our theoretical model. Furthermore, we prove the stability of the trap through centimeter-thick layers of bio-mimicking, elastic materials. Finally, we demonstrate the simultaneous trapping of nanoparticle-loaded microbubbles and activation with an independent acoustic field to trigger the release of the nanoparticles. Overall, using exclusively acoustic powering to position and actuate microbubbles paves the way toward controlled delivery of drug payloads in confined, hard-to-reach locations, with potential in vivo applications.

scholarly journals Influence of droplet coverage on the electrochemical response of planar microelectrodes and potential solving strategies based on nesting concept

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2400
Author(s):  
Yue Yu ◽  
Zhanming Li
Keyword(s):  
Three Dimensional ◽  
Smart Devices ◽  
Electrochemical Biosensors ◽  
Signal Stability ◽  
Interdigitated Microelectrodes ◽  
Electrochemical Response ◽  
3D Printed ◽  
Signal Changes ◽  
The Stability ◽  
Different Diameters

Recently, biosensors have been widely used for the detection of bacteria, viruses and other toxins. Electrodes, as commonly used transducers, are a vital part of electrochemical biosensors. The coverage of the droplets can change significantly based on the hydrophobicity of the microelectrode surface materials. In the present research, screen-printed interdigitated microelectrodes (SPIMs), as one type of planar microelectrode, were applied to investigate the influence of droplet coverage on electrochemical response. Furthermore, three dimensional (3D) printing technology was employed to print smart devices with different diameters based on the nesting concept. Theoretical explanations were proposed to elucidate the influence of the droplet coverage on the electrochemical response. 3D-printed ring devices were used to incubate the SPIMs and the analytical performances of the SPIMs were tested. According to the results obtained, our device successfully improved the stability of the signal responses and eliminated irregular signal changes to a large extent. Our proposed method based on the nesting concept provides a promising method for the fabrication of stable electrochemical biosensors. We also introduced two types of electrode bases to improve the signal stability.

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

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