Changes of in vivo electrical conductivity in the brain and torso related to age, fat fraction and sex using MRI.

This work was inspired by the observation that a majority of MR-electrical properties tomography studies are based on direct comparisons with ex vivo measurements carried out on post-mortem samples in the 90's. As a result, the in vivo conductivity values obtained from MRI in the megahertz range in different types of tissues (brain, liver, tumors, muscles, etc.) found in the literature may not correspond to their ex vivo equivalent, which still serves as a reference for electromagnetic modelling. This study aims to pave the way for improving current databases since the definition of personalized electromagnetic models (e.g. for Specific Absorption Rate estimation) would benefit from better estimation. Seventeen healthy volunteers underwent MRI of both brain and thorax/abdomen using a three-dimensional ultrashort echo-time (UTE) sequence. We estimated conductivity (S/m) in several classes of macroscopic tissue using a customized reconstruction method from complex UTE images, and give general statistics for each of these regions (mean-median-standard deviation). These values are used to find possible correlations with biological parameters such as age, sex, body mass index and/or fat volume fraction, using linear regression analysis. In short, the collected in vivo values show significant deviations from the ex vivo values in conventional databases, and we show significant relationships with the latter parameters in certain organs for the first time, e.g. a decrease in brain conductivity with age.

Can thoraco-abdominal organ boundaries be accurately determined from X-ray and anthropometric surface scans? Implications for body armour system coverage and design.

To optimise soldier protection within body armour systems, knowledge of the boundaries of essential thoraco-abdominal organs is necessary to inform coverage requirements. However, existing methods of organ boundary identification are costly and time consuming, limiting widespread adoption for use on soldier populations. The aim of this study was to evaluate a novel method of using 3D organ models to identify essential organ boundaries from low dose planar X-rays and 3D external surface scans of the human torso. The results revealed that, while possible to reconstruct 3D organs using template 3D organ models placed over X-ray images, the boundary data (relating to the size and position of each organ) obtained from the reconstructed organs differed significantly from MRI organ data. The magnitude of difference varied between organs. The most accurate anatomical boundaries were the left, right, and inferior boundaries of the heart, and lateral boundaries for the liver and spleen. Visual inspection of the data demonstrated that 11 of 18 organ models were successfully integrated within the 3D space of the participant's surface scan. These results suggest that, if this method is further refined and evaluated, it has potential to be used as a tool for estimating body armour coverage requirements.

Feasibility and optimization of19F MRI on a clinical 3T with a large field-of-view torso coil.

Objective.The objective of this work is to: (1) demonstrate fluorine-19 (19F) MRI on a 3T clinical system with a large field of view (FOV) multi-channel torso coil (2) demonstrate an example parameter selection optimization for a19F agent to maximize the signal-to-noise ratio (SNR)-efficiency for spoiled gradient echo (SPGR), balanced steady-state free precession (bSSFP), and phase-cycled bSSFP (bSSFP-C), and (3) validate detection feasibility inex vivotissues.Approach.Measurements were conducted on a 3.0T Discovery MR750w MRI (GE Healthcare, USA) with an 8-channel1H/19F torso coil (MRI Tools, Germany). Numerical simulations were conducted for perfluoropolyether to determine the theoretical parameters to maximize SNR-efficiency for the sequences. Theoretical parameters were experimentally verified, and the sensitivity of the sequences was compared with a 10 min acquisition time with a 3.125 × 3.125 × 3 mm3in-plane resolution. Feasibility of a bSSFP-C was also demonstrated in phantom andex vivotissues.Main Results. Flip angles (FAs) of 12 and 64° maximized the signal for SPGR and bSSFP, and validation of optimal FA and receiver bandwidth showed close agreement with numerical simulations. Sensitivities of 2.47, 5.81, and 4.44ms-0.5mM-1 and empirical detection limits of 20.3, 1.5, and 6.2 mM were achieved for SPGR, bSSFP, and bSSFP-C, respectively. bSSFP and bSSFP-C achieved 1.8-fold greater sensitivity over SPGR (p< 0.01).Significance.bSSFP-C was able to improve sensitivity relative to simple SPGR and reduce both bSSFP banding effects and imaging time. The sequence was used to demonstrate the feasibility of19F MRI at clinical FOVs and field strengths withinex-vivotissues.

Changes in trunk appearance following surgical correction of adolescent idiopathic scoliosis.

PURPOSE: To assess the postoperative appearance of the trunk in surgically treated scoliosis patients after a 2 year follow-up using reliable indices and compare the results with 6-month follow-up. METHODS: Forty-six Adolescent Idiopathic Scoliosis (AIS) patients (female; preop mean age 14.4 ± 2.4 years) who underwent a posterior spinal fusion from 2009 to 2018 were included in this study. All had Lenke 1A thoracic curves, with surface topography taken preoperatively, 6 months and 2 years postoperatively. To assess spinal deformity, we measured the proximal thoracic, main thoracic and thoracolumbar/lumbar Cobb angles in the frontal plane from spinal X-rays and inclinometer angles in the thoracic and lumbar regions. To assess trunk deformity, Back Surface Rotation (BSR) and Trunk Lateral Shift (TLS) were computed along the trunk. We analysed the effect of age, height, weight, Cobb angle, length of follow-up, and surgical technique. We also compared correction rates (CRs) of the spinal and trunk measurements after 6 months and 2 years. RESULTS: Good spinal correction was achieved, with Cobb angles decreasing in the whole cohort. CRs for TLS and BSR were positive (denoting improvement) for 76% and 48% of patients, respectively, after 2 years. Compared with 6 months, the mean TLS CR increased while there was no improvement for BSR on average. We found no significant association after 2 years between truncal index CRs and clinical variables (age, height, weight, preoperative Cobb angles) or surgical technique. However, there were significant correlations between the CRs of TLS and the main thoracic Cobb angle (r = 0.35), and between the CRs of BSR and thoracic inclinometer angle. CONCLUSION: Although more than 55% of the TLS was corrected after 2 years of follow-up, the BSR remained stable over time and the persistence of rib hump on the back surface could be observed. LEVEL OF EVIDENCE: III.

Patient Re-Identification Based on Deep Metric Learning in Trunk Computed Tomography Images Acquired from Devices from Different Vendors.

During radiologic interpretation, radiologists read patient identifiers from the metadata of medical images to recognize the patient being examined. However, it is challenging for radiologists to identify "incorrect" metadata and patient identification errors. We propose a method that uses a patient re-identification technique to link correct metadata to an image set of computed tomography images of a trunk with lost or wrongly assigned metadata. This method is based on a feature vector matching technique that uses a deep feature extractor to adapt to the cross-vendor domain contained in the scout computed tomography image dataset. To identify "incorrect" metadata, we calculated the highest similarity score between a follow-up image and a stored baseline image linked to the correct metadata. The re-identification performance tests whether the image with the highest similarity score belongs to the same patient, i.e., whether the metadata attached to the image are correct. The similarity scores between the follow-up and baseline images for the same "correct" patients were generally greater than those for "incorrect" patients. The proposed feature extractor was sufficiently robust to extract individual distinguishable features without additional training, even for unknown scout computed tomography images. Furthermore, the proposed augmentation technique further improved the re-identification performance of the subset for different vendors by incorporating changes in width magnification due to changes in patient table height during each examination. We believe that metadata checking using the proposed method would help detect the metadata with an "incorrect" patient identifier assigned due to unavoidable errors such as human error.

Re-thinking the value of cross-sectional torso imaging for ground-level fall patients with altered mental status: Outcomes from a level 1 trauma center.

INTRODUCTION: Patients with altered mental status (AMS) are often excluded from studies evaluating the utility of computed tomography of the torso (CTT) after ground level falls (GLF). It is not known whether CTT identifies otherwise undetectable injuries in patients with AMS after GLF. We sought to describe the value of performing CTT in patients with AMS after GLF, and hypothesized that CTT would not identify new, clinically significant injuries in patients with a normal torso physical exam (PE) and normal chest and pelvic radiographs (CXR/PXR). METHODS: Single-institution retrospective cohort study of GLF patients (≤1 m) with and without AMS (GCS <15, blood alcohol level >150 mg/dL, intubation prior to hospital evaluation), 2015-2019. Traumatic injury identification on CTT was evaluated in the context of normal/abnormal torso PE (based on provider documentation) and normal CXR/PXR. RESULTS: 1195 patients met inclusion criteria; 344 had AMS, of which 129 (37.5 %) underwent CTT. A further 851 patients had normal mental status, of which 180 (21.2 %) underwent CTT. Patients with a normal PE with AMS (N = 79) and without AMS (N = 38) had a similar rate of new injury discovery on CTT (6.3% vs. 7.9 %, p = 1.00). Negative PE had a negative predictive value (NPV) for identification of a new, acute traumatic injury of 92.4 % (95 % CI: 0.84-0.96) in patients with AMS while normal PE, CXR, and PXR had a NPV of 96.0 % (95 % CI: 0.80-0.99). Among patients with CTT, patients with AMS had a significantly lower rate of acute traumatic injury on CTT compared to alert patients (26.4 % vs. 48.9 %, p < 0.001). On multivariate analysis, AMS was not positively associated with likelihood of identifying acute traumatic injury on CTT. CONCLUSIONS: In patients sustaining GLFs who present with AMS and who otherwise have a negative PE, CXR, and PXR, CTT is very unlikely to identify new traumatic injuries. Strong consideration should be given to forego cross-sectional imaging in this patient population.

GA-Net: A geographical attention neural network for the segmentation of body torso tissue composition.

PURPOSE: Body composition analysis (BCA) of the body torso plays a vital role in the study of physical health and pathology and provides biomarkers that facilitate the diagnosis and treatment of many diseases, such as type 2 diabetes mellitus, cardiovascular disease, obstructive sleep apnea, and osteoarthritis. In this work, we propose a body composition tissue segmentation method that can automatically delineate those key tissues, including subcutaneous adipose tissue, skeleton, skeletal muscle tissue, and visceral adipose tissue, on positron emission tomography/computed tomography scans of the body torso. METHODS: To provide appropriate and precise semantic and spatial information that is strongly related to body composition tissues for the deep neural network, first we introduce a new concept of the body area and integrate it into our proposed segmentation network called Geographical Attention Network (GA-Net). The body areas are defined following anatomical principles such that the whole body torso region is partitioned into three non-overlapping body areas. Each body composition tissue of interest is fully contained in exactly one specific minimal body area. Secondly, the proposed GA-Net has a novel dual-decoder schema that is composed of a tissue decoder and an area decoder. The tissue decoder segments the body composition tissues, while the area decoder segments the body areas as an auxiliary task. The features of body areas and body composition tissues are fused through a soft attention mechanism to gain geographical attention relevant to the body tissues. Thirdly, we propose a body composition tissue annotation approach that takes the body area labels as the region of interest, which significantly improves the reproducibility, precision, and efficiency of delineating body composition tissues. RESULTS: Our evaluations on 50 low-dose unenhanced CT images indicate that GA-Net outperforms other architectures statistically significantly based on the Dice metric. GA-Net also shows improvements for the 95% Hausdorff Distance metric in most comparisons. Notably, GA-Net exhibits more sensitivity to subtle boundary information and produces more reliable and robust predictions for such structures, which are the most challenging parts to manually mend in practice, with potentially significant time-savings in the post hoc correction of these subtle boundary placement errors. Due to the prior knowledge provided from body areas, GA-Net achieves competitive performance with less training data. Our extension of the dual-decoder schema to TransUNet and 3D U-Net demonstrates that the new schema significantly improves the performance of these classical neural networks as well. Heatmaps obtained from attention gate layers further illustrate the geographical guidance function of body areas for identifying body tissues. CONCLUSIONS: (i) Prior anatomic knowledge supplied in the form of appropriately designed anatomic container objects significantly improves the segmentation of bodily tissues. (ii) Of particular note are the improvements achieved in the delineation of subtle boundary features which otherwise would take much effort for manual correction. (iii) The method can be easily extended to existing networks to improve their accuracy for this application.

Are torso asymmetry and torso displacements in a computer brace model associated with initial in-brace correction in adolescent idiopathic scoliosis?

BACKGROUND: Lack of initial in-brace correction is strongly predictive for brace treatment failure in adolescent idiopathic scoliosis (AIS) patients. Computer-aided design (CAD) technology could be useful in quantifying the trunk in 3D and brace characteristics in order to further investigate the effect of brace modifications on initial in-brace correction and subsequently long-term brace treatment success. The purpose of this pilot study was to identify parameters obtained from 3D surface scans which influence the initial in-brace correction (IBC) in a Boston brace in patients with AIS. METHODS: Twenty-five AIS patients receiving a CAD-based Boston brace were included in this pilot study consisting of 11 patients with Lenke classification type 1 and 14 with type 5 curves. The degree of torso asymmetry and segmental peak positive and negative torso displacements were analyzed with the use of patients' 3D surface scans and brace models for potential correlations with IBC. RESULTS: The mean IBC of the major curve on AP view was 15.9% (SD = 9.1%) for the Lenke type 1 curves, and 20.1% (SD = 13.9%) for the type 5 curves. The degree of torso asymmetry was weakly correlated with patient's pre-brace major curve Cobb angle and negligible correlated with major curve IBC. Mostly weak or negligible correlations were observed between IBC and the twelve segmental peak displacements for both Lenke type 1 and 5 curves. CONCLUSION: Based on the results of this pilot study, the degree of torso asymmetry and segmental peak torso displacements in the brace model alone are not clearly associated with IBC.

Effect of age on shear modulus, muscle thickness, echo intensity of the upper limb, lower limb, and trunk muscles in healthy women.

PURPOSE: This study aimed to examine the effect of age on the mechanical properties, muscle size, and muscle quality in the upper and lower limb and trunk muscles. METHODS: We evaluated the shear modulus (G), muscle thickness (MT), and echo intensity (EI) of the upper and lower limb and trunk muscles of 83 healthy women (21-83-year-old). The G values of some limb muscles were measured in relaxed and stretched positions. RESULTS: Regarding the effect of age on G at the distinct positions, the G of the upper limb muscles were not significantly correlated with age in the relaxed and stretched positions. In contrast, the G of the iliacus showed a significant negative correlation in both positions. Additionally, the G of the rectus femoris had a significant negative correlation only in the relaxed position. Regarding differences among body parts, the G of the lower limb and oblique abdominal muscles showed a significant negative correlation, but no correlation in the upper limb, rectus abdominis, and back muscles. Moreover, MT showed a significant negative correlation with age in the lower limb, abdominal, and erector spinae muscles, but no correlation was detected in the upper limb and lumbar multifidus muscles. EI had a significant positive correlation in all the muscles. CONCLUSION: The effect of age on G depended on body parts, and the G of the lower limb and oblique abdominal muscles negatively associated with age. Additionally, G in the relaxed position may be more susceptible to aging than G in the stretched position.

The Effects of Isometric Fatigue on Trunk Muscle Stiffness: Implications for Shear-Wave Elastography Measurements.

Muscle stiffness has been implicated as a possible factor in low back pain risk. There are few studies on the effects of isometric fatigue on the shear modulus of trunk muscles. This study aimed to investigate the effects of trunk isometric fatigue on the passive and active (during low and high-level contractions) shear moduli of the erector spinae (ES) and superficial and deep multifidus (MF) muscles. We assessed passive and active shear modulus using shear-wave elastography in healthy young participants (n = 22; 11 males, 11 females), before and after an isometric trunk extension fatigue protocol. Maximal voluntary force decreased from 771.2 ± 249.8 N before fatigue to 707.3 ± 204.1 N after fatigue (-8.64%; p = 0.003). Passive shear modulus was significantly decreased after fatigue in the MF muscle (p = 0.006-0.022; Cohen's d = 0.40-46), but not the ES muscle (p = 0.867). Active shear modulus during low-level contraction was not affected by fatigue (p = 0.697-0.701), while it was decreased during high-level contraction for both muscles (p = 0.011; d = 0.29-0.34). Sex-specific analysis indicated the decrease in ES shear modulus was significant in males (p = 0.015; d = 0.31), but not in females (p = 0.140). Conversely, the shear modulus in superficial MF had a statistically significant decrease in females (p = 0.002; d = 0.74) but not in males (p = 0.368). These results have important implications for further investigations of the mechanistic interaction between physical workloads, sex, muscle stiffness (and other variables affecting trunk stability and neuromuscular control), and the development/persistence of low back pain.

A non-invasive method for scoliosis assessment-A new mathematical concept using polar angle.

Scoliosis is one of the most common pediatric spinal diseases that leads to a three-dimensional deformity of the spine and has a high risk of progression during growth. Regular clinical monitoring and follow-up X-rays are needed to providing proper treatment at that time. Repetitive X-rays can results in an increased risk of radiation related health problems. We present a non-invasive, ionizing radiation-free method for assessing scoliosis and its progression from the 3D images of the body torso, captured by a body scanner. A new concept is introduced based on a mathematical method in polar coordinate system to quantify and characterize the deformities in the torso from 2D transverse cross-sections of the 3D torso images at example cases for a healthy individual and for two patients with scoliosis. To capture quantitatively the characteristics of scoliosis, and to verify them at the example cases two asymmetry parameters and a linear fitting parameter are calculated: a) back side area asymmetry, b) left right area asymmetry, and c) coefficient of determination (R2). Within the analyzed patients, both the area asymmetries are maximum at the apex of scoliosis, and increase with the severity of scoliosis. R2 values are smaller in the case of patients compared with the healthy. Furthermore, the parameters show a trend when compared with the Cobb angle from the X-ray and the findings match with clinical examination. Therefore, the quantities are able to capture, certain characteristics associated with scoliosis. These quantities can be compared as a measure of deformities of torso, during the follow-up examinations in the future, without ionizing radiations.

Comparison of the mass and amount of intramuscular non-contractile tissue of the trunk and lower extremity muscles between patients with Parkinson's disease and community-dwelling older adults.

OBJECTIVE: This study compared the masses and amounts of intramuscular non-contractile tissue of the trunk and lower extremity muscles, sagittal spinal alignment, and mobility and balance ability between patients with Parkinson's disease (PD) and older adults. METHODS: This study included 26 older adults (control [CTR] group) and eight patients with PD (PD group). Muscle thicknesses and echo intensities of the trunk and lower extremity muscles were measured using an ultrasound imaging device. Sagittal spinal alignments in the standing and prone positions were assessed using a Spinal Mouse. Mobility capacity was assessed based on the measurements of usual and maximal walking speeds, timed up-and-go (TUG) time, and five-chair-stand time, while balance ability was assessed based on the measurement of one-legged stance (OLS) time. RESULTS: Our results showed significantly lower gluteus maximus and tibialis anterior muscle thicknesses, higher thickness of the short head of the biceps femoris muscle, and higher echo intensity of the gluteus maximus muscle in the PD group than in the CTR group. Lumbar lordosis angle in the standing position, usual and maximal walking speeds, and OLS time were significantly lower, while the TUG and five-chair-stand times were significantly higher in the PD group than in the CTR group. The other factors did not differ significantly between groups. CONCLUSIONS: Our results revealed lower masses of the gluteus maximus and tibialis anterior muscles, higher mass of the short head of the biceps femoris muscle, and higher amounts of intramuscular non-contractile tissue of the gluteus maximus muscle in patients with PD.

Comparison of the Upper and Lower Extremity and Trunk Muscle Masses between Children with Down Syndrome and Children with Typical Development.

PURPOSE: Comparison of not only the upper and lower extremity but also trunk muscle masses measured by means of an ultrasound imaging device between children with Down syndrome (DS) and children with typical development (TD). METHODS: The study included 35 children with TD (TD group) and 26 children with DS (DS group). The upper and lower extremity and trunk muscle thicknesses were measured using an ultrasound imaging device. RESULTS: The thicknesses of the rectus abdominis, obliquus externus and internus abdominis, rectus femoris, and short head of the biceps femoris muscles were significantly lower in the DS group than in the TD group. The thicknesses of the other upper and lower extremity and trunk muscles did not differ significantly between the groups. CONCLUSIONS: The results of this study demonstrated lower masses of trunk flexor and knee extensor and flexor muscles in children with DS compared to those in children with TD.

Moiré topography as a screening and diagnostic tool-A systematic review.

Diagnostic investigation can be carried out using non-radiological and non-contact methods. Moiré topography (MT) seems to be a viable alternative to radiographic research in evaluating the spine and/or trunk deviations. The aim of this systematic review was to analyze the current knowledge regarding the reliability and validity of Moiré topography as a screening and diagnostic tool. The systematic review was performed from 2010 until March 2021 in the PubMed, EBSCO, Web of Science, and Scopus databases, according to the eligibility criteria. This review fulfilled the following criteria according to the PICO system: population (children and adolescents), intervention (MT measurement), comparison (repeated MT measurements, MT compared to Cobb angle or scoliometer), outcome (reliability and validity of MT). Eight studies fulfilled the inclusion criteria for further analysis. All the studies were assessed to be of high quality. Included studies found that MT had high repeatability and high intraobserver and interobserver correlation, and correlation between MT parameters and radiographic Cobb angle ranged from moderate to high. The authors reported difficulty in defining the cut-off values for MT parameter (Surface Trunk Rotation-STR), and unsatisfactory sensitivity and specificity of MT examination. The studies did not reveal the advantage of MT as a screening method in the detection of idiopathic scoliosis in comparison to radiograph. Based on the evidence from eight studies, the results indicated moderate evidence for reliability and validity of Moiré topography as a screening and diagnostic tool. There is still no strong evidence for the accuracy of MT.

Novel Computer-Aided Diagnosis Software for the Prevention of Retained Surgical Items.

BACKGROUND: Retained surgical items are a serious human error. Surgical sponges account for 70% of retained surgical items. To prevent retained surgical sponges, it is important to establish a system that can identify errors and avoid the occurrence of adverse events. To date, no computer-aided diagnosis software specialized for detecting retained surgical sponges has been reported. We developed a software program that enables easy and effective computer-aided diagnosis of retained surgical sponges with high sensitivity and specificity using the technique of deep learning, a subfield of artificial intelligence. STUDY DESIGN: In this study, we developed the software by training it through deep learning using a dataset and then validating the software. The dataset consisted of a training set and validation set. We created composite x-rays consisting of normal postoperative x-rays and surgical sponge x-rays for a training set (n = 4,554) and a validation set (n = 470). Phantom x-rays (n = 12) were prepared for software validation. X-rays obtained with surgical sponges inserted into cadavers were used for validation purposes (formalin: Thiel's method = 252:117). In addition, postoperative x-rays without retained surgical sponges were used for the validation of software performance to determine false-positive rates. Sensitivity, specificity, and false positives per image were calculated. RESULTS: In the phantom x-rays, both the sensitivity and specificity in software image interpretation were 100%. The software achieved 97.7% sensitivity and 83.8% specificity in the composite x-rays. In the normal postoperative x-rays, 86.6% specificity was achieved. In reading the cadaveric x-rays, the software attained both sensitivity and specificity of >90%. CONCLUSIONS: Software with high sensitivity for diagnosis of retained surgical sponges was developed successfully.

Factors affecting the prevalence of idiopathic scoliosis among children aged 8-15 years in Prishtina, Kosovo.

Prospective study, Level of evidence II. The aim of the study was to assess the prevalence of scoliosis among children aged 8-15 years old and to identify the impact of schoolbag weight in developing adolescent idiopathic scoliosis (AIS). AIS is a common disease whose prevalence varies between countries and gender, with an increased rate among females compared to males. Screening children in primary school settings for idiopathic scoliosis (IS) is an important public health issue and is crucial for early detection, prevention of further deformity, and healthy child growth. Our sample was composed of 1619 pupils from the municipality of Prishtina, surveyed from March to April 2019. Measurements were made with a scoliometer on the basis of the Adams test process. Three measurements were taken for each of the participants. Additionally, all the pupils were subjected to bare-foot height and weight measurements with and without school bags. The mean ± standard deviation age of pupils was 11.67 ± 2.00 years old and 49% were females. The prevalence of the angle of trunk rotation (ATR) ≥ 5 ° was 26.1%, females had 1.49 higher odds (95%CI 1.19-1.86) to develop an ATR of ≥ 5° compared to males. The highest rate of ATR of ≥ 5° was seen among the ninth-grade students (31.3%). 56.5% of 4th grade students carry a schoolbag weighing over 12.5% of body weight. Relatively high prevalence of idiopathic scoliosis was found in primary schools in Prishtina. The highest prevalence was found in students attending the ninth grade, while females gender dominated.

Age-related changes in muscle quality and development of diagnostic cutoff points for myosteatosis in lumbar skeletal muscles measured by CT scan.

BACKGROUND & AIMS: We have sought to develop proper and useful indices for muscle quality measurements other than muscle attenuation (Hounsfield unit; HU) and to determine the diagnostic cutoff points for myosteatosis by using those indices measured at the L3 lumbar vertebrae level by CT scan. METHODS: This cross-sectional analysis included 20,664 healthy adult subjects (12,697 men and 7967 women) who underwent abdominal CT scans. Total abdominal muscle area (TAMA), on the L3 vertebra was demarcated using predetermined thresholds. Intermuscular adipose tissue area (IMAT) and skeletal muscle area (SMA) were measured. SMA was divided into normal attenuation muscle area (NAMA) and low attenuation muscle area (LAMA). Their various indices were calculated. We identified the sex-specific mean values of NAMA, LAMA, IMAT, and their indices and the cutoff points equivalent to the T-scores in the young reference group. RESULTS: The mean values of the NAMA and NAMA indices decreased with age in both sexes, LAMA, IMAT, and their indices showed an increasing tendency with age in both sexes. When using T-score < -2.0 as the cutoff for myosteatosis, the sex-specific cutoff points of NAMA, NAMA/BMI, NAMA/TAMA index, and SMA and TAMA attenuation in men and women were 103.0 and 64.5 cm2, 4.0 and 2.8, 66.4 and 65.1, 40.2 and 39.9 HU, and 34.1 and 33.5 HU, respectively. Using these cutoff points, the prevalence of myosteatosis by NAMA, NAMA/BMI, NAMA/TAMA index, or SMA or TAMA attenuation ranged from 5.9 to 8.8% in men and from 10.2 to 20.5% in women. CONCLUSIONS: The NAMA/TAMA index developed in this study was useful for assessing myosteatosis. This is the first study to report the sex-specific diagnostic cutoff points for myosteatosis of trunk muscles based on T-scores measured by CT scans in healthy population. These diagnostic cutoff points may be particularly useful in the treatment and prevention of sarcopenia and myosteatosis.

Truncal Changes in Patients Suffering Severe Hip or Knee Osteoarthritis: A Surface Topography Study.

BACKGROUD: Osteoarthritis (OA) of the hip and knee is a degenerative disease with complications, including reduced range of motion and pain. Although OA of the hip and knee is common, there are few studies that investigated if patients with this condition had affected morphological truncal parameters. The objectives of this study were to compare the morphology of the spine and the pelvis of patients with hip or knee OA to that of a control group (CG) and to comment on the proposed mechanisms of these changes and the clinical effects on patients. METHODS: This study included three groups of individuals. The first group consisted of 34 patients (15 men and 19 women with a mean age of 67.62 ± 8.28 years) suffering from hip OA. The second group consisted of 45 patients (11 men and 34 women with a mean age of 72.47 ± 7.0 years) suffering from knee OA. These patients were compared with a CG, which consisted of 25 individuals (13 men and 12 women with a mean age of 69.28 ± 10.11 years). The DIERS formetric 4D analysis system was used to calculate several truncal parameters in all planes. All analyses were accomplished using the SPSS ver. 17.0, and p < 0.05 was used to determine statistical significance. RESULTS: Patients with hip OA presented with significantly increased values than those in the CG for sagittal imbalance, scoliosis angle, vertebral rotation, trunk torsion, and pelvic obliquity, and decreased values than those in the CG for fleche lombaire. Patients with knee OA presented with significantly increased values than those in the CG for sagittal imbalance, apical deviation, scoliosis angle, vertebral rotation, trunk torsion, and pelvic obliquity. Patients with hip or knee OA, compared to the CG, had greater forward inclination of the spine, greater scoliosis, greater vertebral rotation and trunk torsion, and greater obliquity of the pelvis at the frontal plane. CONCLUSIONS: Patients with severe hip or knee OA could have truncal morphology alterations, in addition to reduced hip or knee range of motion and pain. These alterations could cause significant negative effects, which may then seriously affect the patients' quality of life.

The use of statistical modelling to identify important parameters for the shape of the torso following surgery for adolescent idiopathic scoliosis.

The surgical strategy in adolescent idiopathic scoliosis (AIS) aims to recreate the symmetry of the torso. This requires the minimisation of both the size of the scoliosis and the angulation between the sides of the torso, along with the recreation of a normal thoracic kyphosis. This study uses predictive modelling to identify the significance of the value of the pre-operative parameters, and the change in the magnitude of the parameters as a result of an operation on the shape of the torso using the 'most prominent points'; two areas of maximum prominence on either side of the spine with x, y and z coordinates. The pre-operative values, and the change in magnitude between the pre and post-operative values, for scoliosis, kyphosis and skin angulation from a group of Lenke 1 convex to the right AIS were analysed with measures collected using Integrated Spine Imaging System 2 surface topography and compared with those without visible spinal deformity. The models best explained the z coordinate and least well explained the x coordinate, although there was a contribution to all of the models that remained unexplained. The parameters that affected the position of the coordinates in the model differed between the models. This confirms that surgically altering the shape of the spine and torso whilst correcting an AIS does not lead to a symmetrical torso. There are as yet, undefined factors which contribute to the shape of the torso and which if identified and corrected surgically would lead to greater symmetry post-operatively.

Female kinematics and muscle responses in lane change and lane change with braking maneuvers.

OBJECTIVE: The primary aim of this article is to extensively study female occupant kinematics and muscle activations in vehicle maneuvers potentially occurring in precrash situations and with different seat belt configurations. The secondary aim is to provide validation data for active human body models (AHBMs) of female occupants in representative precrash loading situations. METHODS: Front seat female passengers wearing a 3-point seat belt, with either standard or pre-pretensioning functionality, were subjected to multiple autonomously carried-out lane change and lane change with braking maneuvers while traveling at 73 km/h. This article quantifies the head center of gravity and T1 vertebra body (T1) linear and rotational displacements. This article also includes surface electromyography (EMG) data collected from 38 muscles in the neck, torso, and upper and lower extremities, all normalized by maximum voluntary contraction (MVC). The raw EMG data were filtered, rectified, and smoothed. Separate Wilcoxon signed-rank tests were performed on EMG onset and amplitude as well as peak displacements of head and T1 considering 2 paired samples with the belt configuration as an independent variable. RESULTS: Significantly smaller lateral and forward displacements for head and T1 were found with the pre-pretensioner belt versus the standard belt (P < .05). Averaged muscle activity, mainly in the neck, lumbar extensor, and abdominal muscles, increased up to 16% MVC immediately after the vehicle accelerated in the lateral direction. Muscles in the right and left sides of the body displayed differences in activation time and amplitude relative to the vehicle's lateral motion. For specific muscles, lane changes with the pre-pretensioner belt resulted in earlier muscle activation onsets and significantly smaller activation amplitudes compared to the standard belt (P < .05). CONCLUSIONS: The presented results from female passengers complement the previously published results from male passengers subjected to the same loading scenarios. The data provided in this article can be used for validation of AHBMs of female occupants in both sagittal and lateral loading scenarios potentially occurring prior to a crash. Additionally, our results show that a pre-pretensioner belt decreases muscle activation onset and amplitude as well as forward and lateral displacements of head and T1 compared to a standard belt, confirming previously published results.