Shear wave elastography of the radial nerve in healthy subjects

Objective This study was performed to examine the sonoelastographic features of the radial nerve in healthy subjects. Methods In this observational cross-sectional study, shear wave elastography was used to evaluate the radial nerve. The cross-sectional area and stiffness were measured. Results The study included 37 nerves in 20 healthy adult subjects. The mean cross-sectional area of the radial nerve at the arm was 6.1 mm2. The mean stiffness of the radial nerve in the short axis was 30.3 kPa, and that in the long axis was 34.9 kPa. The elasticity measurements were significantly different between the long axis and short axis. Conclusion The elastic modulus of the radial nerve was studied in healthy subjects and can serve as a reference for future assessment of different radial nerve pathologies.

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Atrophy patterns in isolated subscapularis lesions

BMC Musculoskeletal Disorders ◽

10.1186/s12891-021-04241-5 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Gernot Seppel ◽

Andreas Voss ◽

Daniel J. H. Henderson ◽

Simone Waldt ◽

Bernhard Haller ◽

...

Keyword(s):

Muscle Atrophy ◽

Area Ratio ◽

Cross Sectional Area ◽

Control Group ◽

Sectional Area ◽

Cross Sectional ◽

Subscapularis Muscle ◽

Mri Scans ◽

The Mean ◽

The Cross

Abstract Background While supraspinatus atrophy can be described according to the system of Zanetti or Thomazeau there is still a lack of characterization of isolated subscapularis muscle atrophy. The aim of this study was to describe patterns of muscle atrophy following repair of isolated subscapularis (SSC) tendon. Methods Forty-nine control shoulder MRI scans, without rotator cuff pathology, atrophy or fatty infiltration, were prospectively evaluated and subscapularis diameters as well as cross sectional areas (complete and upper half) were assessed in a standardized oblique sagittal plane. Calculation of the ratio between the upper half of the cross sectional area (CSA) and the total CSA was performed. Eleven MRI scans of patients with subscapularis atrophy following isolated subscapularis tendon tears were analysed and cross sectional area ratio (upper half /total) determined. To guarantee reliable measurement of the CSA and its ratio, bony landmarks were also defined. All parameters were statistically compared for inter-rater reliability, reproducibility and capacity to quantify subscapularis atrophy. Results The mean age in the control group was 49.7 years (± 15.0). The mean cross sectional area (CSA) was 2367.0 mm2 (± 741.4) for the complete subscapularis muscle and 1048.2 mm2 (± 313.3) for the upper half, giving a mean ratio of 0.446 (± 0.046). In the subscapularis repair group the mean age was 56.7 years (± 9.3). With a mean cross sectional area of 1554.7 mm2 (± 419.9) for the complete and of 422.9 mm2 (± 173.6) for the upper half of the subscapularis muscle, giving a mean CSA ratio of 0.269 (± 0.065) which was seen to be significantly lower than that of the control group (p < 0.05). Conclusion Analysis of typical atrophy patterns of the subscapularis muscle demonstrates that the CSA ratio represents a reliable and reproducible assessment tool in quantifying subscapularis atrophy. We propose the classification of subscapularis atrophy as Stage I (mild atrophy) in case of reduction of the cross sectional area ratio < 0.4, Stage II (moderate atrophy) in case of < 0.35 and Stage III (severe atrophy) if < 0.3.

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The influence of muscle pennation angle and cross-sectional area on contact forces in the ankle joint

The Journal of Strain Analysis for Engineering Design ◽

10.1177/0309324716669250 ◽

2016 ◽

Vol 52 (1) ◽

pp. 12-23 ◽

Cited By ~ 7

Author(s):

Ran S Sopher ◽

Andrew A Amis ◽

D Ceri Davies ◽

Jonathan RT Jeffers

Keyword(s):

Pennation Angle ◽

Muscle Architecture ◽

Cross Sectional Area ◽

Contact Forces ◽

Sectional Area ◽

Muscle Forces ◽

Cross Sectional ◽

Contact Loads ◽

The Mean ◽

And Function

Data about a muscle’s fibre pennation angle and physiological cross-sectional area are used in musculoskeletal modelling to estimate muscle forces, which are used to calculate joint contact forces. For the leg, muscle architecture data are derived from studies that measured pennation angle at the muscle surface, but not deep within it. Musculoskeletal models developed to estimate joint contact loads have usually been based on the mean values of pennation angle and physiological cross-sectional area. Therefore, the first aim of this study was to investigate differences between superficial and deep pennation angles within each muscle acting over the ankle and predict how differences may influence muscle forces calculated in musculoskeletal modelling. The second aim was to investigate how inter-subject variability in physiological cross-sectional area and pennation angle affects calculated ankle contact forces. Eight cadaveric legs were dissected to excise the muscles acting over the ankle. The mean surface and deep pennation angles, fibre length and physiological cross-sectional area were measured. Cluster analysis was applied to group the muscles according to their architectural characteristics. A previously validated OpenSim model was used to estimate ankle muscle forces and contact loads using architecture data from all eight limbs. The mean surface pennation angle for soleus was significantly greater (54%) than the mean deep pennation angle. Cluster analysis revealed three groups of muscles with similar architecture and function: deep plantarflexors and peroneals, superficial plantarflexors and dorsiflexors. Peak ankle contact force was predicted to occur before toe-off, with magnitude greater than five times bodyweight. Inter-specimen variability in contact force was smallest at peak force. These findings will help improve the development of experimental and computational musculoskeletal models by providing data to estimate force based on both surface and deep pennation angles. Inter-subject variability in muscle architecture affected ankle muscle and contact loads only slightly. The link between muscle architecture and function contributes to the understanding of the relationship between muscle structure and function.

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A computed method for noninvasive MRI assessment of pulmonary arterial hypertension

Journal of Applied Physiology ◽

10.1152/japplphysiol.00292.2003 ◽

2004 ◽

Vol 96 (2) ◽

pp. 463-468 ◽

Cited By ~ 49

Author(s):

Eric Laffon ◽

Christophe Vallet ◽

Virginie Bernard ◽

Michel Montaudon ◽

Dominique Ducassou ◽

...

Keyword(s):

Arterial Pressure ◽

Pulmonary Arterial Pressure ◽

Cross Sectional Area ◽

Physical Parameters ◽

Sectional Area ◽

Biophysical Parameters ◽

Cross Sectional ◽

Mean Pulmonary Arterial Pressure ◽

Pulmonary Arterial ◽

The Mean

The present method enables the noninvasive assessment of mean pulmonary arterial pressure from magnetic resonance phase mapping by computing both physical and biophysical parameters. The physical parameters include the mean blood flow velocity over the cross-sectional area of the main pulmonary artery (MPA) at the systolic peak and the maximal systolic MPA cross-sectional area value, whereas the biophysical parameters are related to each patient, such as height, weight, and heart rate. These parameters have been measured in a series of 31 patients undergoing right-side heart catheterization, and the computed mean pulmonary arterial pressure value (PpaComp) has been compared with the mean pressure value obtained from catheterization (PpaCat) in each patient. A significant correlation was found that did not differ from the identity line PpaComp = PpaCat ( r = 0.92). The mean and maximal absolute differences between PpaComp and PpaCat were 5.4 and 11.9 mmHg, respectively. The method was also applied to compute the MPA systolic and diastolic pressures in the same patient series. We conclude that this computed method, which combines physical (whoever the patient) and biophysical parameters (related to each patient), improves the accuracy of MRI to noninvasively estimate pulmonary arterial pressures.

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Internal Jugular Vein Cross-Sectional Area and Cerebrospinal Fluid Pulsatility in the Aqueduct of Sylvius: A Comparative Study between Healthy Subjects and Multiple Sclerosis Patients

PLoS ONE ◽

10.1371/journal.pone.0153960 ◽

2016 ◽

Vol 11 (5) ◽

pp. e0153960 ◽

Cited By ~ 9

Author(s):

Clive B. Beggs ◽

Christopher Magnano ◽

Pavel Belov ◽

Jacqueline Krawiecki ◽

Deepa P. Ramasamy ◽

...

Keyword(s):

Multiple Sclerosis ◽

Cerebrospinal Fluid ◽

Comparative Study ◽

Internal Jugular Vein ◽

Healthy Subjects ◽

Jugular Vein ◽

Cross Sectional Area ◽

Sectional Area ◽

Cross Sectional ◽

Multiple Sclerosis Patients

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Patients with Achilles Tendon Rupture Have a Degenerated Contralateral Achilles Tendon: An Elastography Study

BioMed Research International ◽

10.1155/2018/2367615 ◽

2018 ◽

Vol 2018 ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Qianru Li ◽

Qi Zhang ◽

Yehua Cai ◽

Yinghui Hua

Keyword(s):

Achilles Tendon ◽

Axial Strain ◽

Achilles Tendon Rupture ◽

Cross Sectional Area ◽

Control Group ◽

Computer Assisted ◽

Study Group ◽

Sectional Area ◽

Cross Sectional ◽

The Mean

Purpose. To evaluate differences of Achilles tendon (AT) hardness and morphology between asymptomatic tendons in patients with acute AT ruptures on the contralateral side and asymptomatic tendons in healthy people by using computer-assisted quantification on axial-strain sonoelastography (ASE). Methods. The study consisted of 33 asymptomatic tendons in 33 patients (study group) and 34 tendons in 19 healthy volunteers (control group). All the tendons were examined by both ASE and conventional ultrasound. Computer-assisted quantification on ASE was applied to extract hardness variables, including the mean (Hmean), 20th percentile (H20), median (H50) and skewness (Hsk) of the hardness within tendon, and the ratio of the mean hardness within tendon to that outside tendon (Hratio) and three morphological variables: the thickness (THK), cross-sectional area, and eccentricity (ECC) of tendons. Results. The Hmean, Hsk, H20, H50, and Hratio in the proximal third of the tendon body in study group were significantly smaller than those in control group (Hmean: 0.43±0.09 vs 0.50±0.07, p=0.001; Hsk: -0.53±0.51 vs -1.09±0.51, p<0.001; H20: 0.31±0.10 vs 0.40±0.10, p=0.001; H50: 0.45±0.10 vs 0.53±0.08, p<0.001; Hratio: 1.01±0.25 vs 1.20±0.23, p=0.003). The THK and cross-sectional area of tendons in the study group were larger than those in the control group (p<0.05). Conclusions. As a quantitative objective method, the computer-assisted ASE reveals that the asymptomatic ATs contralateral to acute rupture are softer than those of healthy control group at the proximal third and the asymptomatic tendons in people with rupture history are thicker, larger, and rounder than those of normal volunteers especially at the middle and distal thirds of AT body.

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Liver ultrasound elastography for the evaluation of periportal fibrosis in schistosomiasis mansoni: A cross-sectional study

10.1101/450494 ◽

2018 ◽

Author(s):

Joelma Carvalho Santos ◽

Andrea Dória Batista ◽

Carla Maria Mola Vasconcelos ◽

Roberto Souza Lemos ◽

Valter Romão de Souza ◽

...

Keyword(s):

Shear Wave ◽

Shear Wave Elastography ◽

Cross Sectional Study ◽

Cutoff Point ◽

Sectional Study ◽

Cross Sectional ◽

Predictive Values ◽

Cutoff Value ◽

Periportal Fibrosis ◽

Schistosomiasis Mansoni

AbstractBackgroundARFI elastrography has been used as a noninvasive method to assess the severity of liver fibrosis in viral hepatitis, although with few studies in schistosomiasis mansoni. We aimed to evaluate the performance of point shear wave elastography (pSWE) for predicting significant periportal fibrosis (PPF) in schistosomotic patients and to determine its best cutoff point.Methodology/Principal findingsThis cross-sectional study included 358 adult schistosomotic patients subjected to US and pSWE on the right lobe. Two hundred two patients (62.0%) were women, with a median age of 54 (ranging 18-92) years. The pSWE measurements were compared to the US patterns of PPF, as gold standard, according to the Niamey classification. The performance of pSWE was calculated as the area under the ROC curve (AUC). Patients were further classified into two groups: 86 patients with mild PPF and 272 patients with significant PPF. The median pSWE of the significant fibrosis group was higher (1.40 m/s) than that of mild fibrosis group (1.14 m/s, p<0.001). AUC was 0.719 with ≤1.11 m/s as the best cutoff value for excluding significant PPF. Sensitivity and negative predictive values were 80.5% and 40.5%, respectively. Whereas, for confirming significant PPF, the best cutoff value was >1.39 m/s, with specificity of 86.1% and positive predictive value of 92.0%.Conclusions/SignificancepSWE was able to differentiate significant from mild PPF, with better performance to predict significant PPF.Author summaryIn the developing world, over 207 million people are infected with parasitic Schistosoma worms. Among the species of Schistosoma that infect humans Schistosoma mansoni is one of the most common causes of illness. Here, we investigated the performance of point shear wave elastography (pSWE) for predicting significant periportal fibrosis (PPF) in schistosomotic patients and to determine its best cutoff point. We examined 358 people from northeast of Brazil for Schistosoma infections. The present study showed that pSWE was able to differentiate significant from mild PPF, with better performance to predict significant PPF.

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INDIRECT DECOMPRESSION BY LATERAL FUSION: ANALYSIS OF SAGITAL ALIGNMENT

Coluna/Columna ◽

10.1590/s1808-185120212001233732 ◽

2021 ◽

Vol 20 (1) ◽

pp. 50-54

Author(s):

Thyago Guirelle Silva ◽

Rodrigo Augusto do Amaral ◽

Raphael Rezende Pratali ◽

Luiz Pimenta

Keyword(s):

Magnetic Resonance ◽

Pelvic Incidence ◽

Magnetic Resonance Images ◽

Cross Sectional Area ◽

Disc Height ◽

Lower Limbs ◽

Sectional Area ◽

Cross Sectional ◽

Indirect Decompression ◽

The Mean

ABSTRACT Objective: To verify the effectiveness of indirect decompression after lateral access fusion in patients with high pelvic incidence. Methods: A retrospective, non-comparative, non-randomized analysis of 22 patients with high pelvic incidence who underwent lateral access fusion, 11 of whom were male and 11 female, with a mean age of 63 years (52-74), was conducted. Magnetic resonance exams were performed within one year after surgery. The cross-sectional area of the thecal sac, anterior and posterior disc heights, and bilateral foramen heights, measured pre- and postoperatively in axial and sagittal magnetic resonance images, were analyzed. The sagittal alignment parameters were measured using simple radiographs. The clinical results were evaluated using the ODI and VAS (back and lower limbs) questionnaires. Results: In all cases, the technique was performed successfully without neural complications. The mean cross-sectional area increased from 126.5 mm preoperatively to 174.3 mm postoperatively. The mean anterior disc height increased from 9.4 mm preoperatively to 12.8 mm postoperatively, while the posterior disc height increased from 6.3 mm preoperatively to 8.1 mm postoperatively. The mean height of the right foramen increased from 157.3 mm in the preoperative period to 171.2 mm in the postoperative period and that of the left foramen increased from 139.3 mm in the preoperative to 158.9 mm in the postoperative. Conclusions: This technique is capable of correcting misalignment in spinal deformity, achieving fusion and promoting the decompression of neural elements. Level of evidence III; Retrospective study.

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The Vertical Mean Force and Moment of Submerged Bodies Under Waves

Journal of Ship Research ◽

10.5957/jsr.1971.15.3.231 ◽

1971 ◽

Vol 15 (03) ◽

pp. 231-245 ◽

Cited By ~ 2

Author(s):

C. M. Lee ◽

J. N. Newman

Keyword(s):

Free Surface ◽

Added Mass ◽

Cross Sectional Area ◽

The Body ◽

Slender Body ◽

Longitudinal Distribution ◽

Vertical Force ◽

Sectional Area ◽

Cross Sectional ◽

The Mean

A neutrally buoyant slender body of arbitrary sectional form, submerged beneath a free surface, is free to respond to an incident plane progressive wave system. The fluid is assumed inviscid, incompressible, homogeneous and infinitely deep. The first-order oscillatory motion of the body and the second-order time-average vertical force and pitching moment acting on the body are obtained in terms of Kochin's function. By use of slender-body theory for a deeply submerged body, the final expressions for the mean force and the moment are shown to depend on the longitudinal distribution of sectional area and added mass and on the amplitude and the frequency of the ambient surface waves. The magnitude of the mean force for various simple geometric cylinders is compared with that of a circular cylinder of equal cross-sectional area. The mean force on a nonaxisymmetric body is often approximated by replacing the section with circular profiles of equivalent cross-sectional area. A better scheme of approximation is presented, based on a simple way of estimating the two-dimensional added mass. It is expected that the effect of the cross-sectional geometry on mean vertical force and moment will be more significant when the body is very close to the free surface.

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