Cross-sectional Area Measurements Research Articles

Early predictive value of ultrasound measurements of rectus femoris cross-sectional area to diagnose ICU-acquired weakness in patients undergoing invasive mechanical ventilation: a prospective cohort study

BackgroundThe diagnosis of ICU-acquired weakness (ICUAW) may be delayed due to the complexity of critically ill patients. This study aimed to investigate the value of ultrasound measurements of rectus femoris cross-sectional area (RFCSA) in predicting ICUAW in patients undergoing invasive mechanical ventilation.MethodsThis was a prospective cohort study of patients undergoing mechanical ventilation for at least 48 h. RFCSA was measured using ultrasound in patients upon ICU admission and followed until discharge. Using the Medical Research Council score as the gold standard, we evaluated the diagnostic value of ultrasound measurements in predicting ICUAW. Kaplan–Meier curves were constructed to evaluate and compare the length of ICU stay and duration of invasive mechanical ventilation between patients with and without ICUAW.ResultsAmong the 76 patients, 34 (44.7%) were diagnosed with ICUAW using the Medical Research Council score as the gold standard. The RFCSA atrophy rate between day 1 and day 3 was significantly higher in the ICUAW group (7.9 ± 2.8% vs. 4.3 ± 2.1%, p < 0.001). By utilizing a cutoff point of 6.9%, we discovered that the RFCSA atrophy rate exhibited excellent diagnostic accuracy in predicting ICUAW, with a sensitivity of 76.5% and specificity of 92.9%. In ICUAW patients diagnosed based on an RFCSA atrophy rate, the proportion of patients with an ICU stay longer than 14 days was 42.9%, which was significantly higher compared to 22.9% in the non-ICUAW group (HR: 1.768; 95% CI 1.128–2.772; p = 0.006). Similarly, the proportion of patients continuing mechanical ventilation at 14 days was 28.6% versus 4.2% between the two groups (HR: 1.988; 95% CI 1.266–3.120; p < 0.001).ConclusionUltrasound measurements of RFCSA provide a reliable method for diagnosing ICUAW and indicating prognosis in patients undergoing invasive mechanical ventilation.

Influence of perch provision during rearing on activity and musculoskeletal health of pullets.

Prior research suggests exercise during pullet rearing can mitigate lay-phase bone fractures by strengthening muscles, enhancing balance, and increasing bone mass. This study aimed to confirm that Hy-Line brown pullets with multi-tier perches show increased activity and improved musculoskeletal health. Pullets (n = 810) were randomly allocated to housing systems, either with multi-tier perches (P; n = 15 pens) or without (NP; n = 15 pens), spanning from 0-17 weeks of age. At 5, 11, and 17 weeks, individual birds were meticulously monitored for activity using accelerometers over three consecutive days (n = 90 randomly selected birds/week). At 11 and 17 weeks, 60 birds underwent euthanasia and computed tomography (CT) scans to ascertain tibiotarsal bone mineral density and cross-sectional area measurements. Post-CT scanning, birds were dissected for muscle size, tibiotarsal breaking strength, and tibiotarsal ash percentage measurements. Additionally, serum concentrations of bone-specific alkaline phosphatase and procollagen type 1 N-terminal propeptide were assessed as markers of bone formation (n = 90 birds/week). Pullet group P exhibited heightened vertical activity (P<0.05), with no discernible differences in overall activity (P>0.05) during weeks 5, 11, and 17 compared to group NP. Tibiotarsal bones of P pullets demonstrated superior total and cortical bone mineral density at week 11, alongside increased cortical bone cross-sectional areas and heightened total and cortical bone mineral densities at week 17 (P<0.05) compared to NP pullets. At week 11, P pullets displayed larger leg muscles, including triceps, pectoralis major and minor, and leg muscles at week 17 (P<0.05) compared to NP pullets. Notably, at both weeks, P pullets' tibiae exhibited greater breaking strengths, higher ash percentages, and elevated concentrations of bone-specific alkaline phosphatase and procollagen type 1 N-terminal propeptide compared to NP pullets (P<0.05). The study findings underscore the benefits of providing multi-tier perches for pullets, serving as a valuable tool for enhancing bird activity and musculoskeletal health preceding the lay phase.

Corrosion Protection of Embedded Steel Reinforcement Using Canarium Schweinfurthiia Exudate for Coastal Concrete Structures

This experimental study evaluated the effects of corrosion on the bond behavior and structural integrity of reinforced concrete. A total of 36 concrete cube specimens containing reinforcing steel bars were divided into control, uncoated, and Canarium schweinfurthiia exudate/resin coated groups and immersed in 5% NaCl solution for 360 days. Periodic tests were conducted to analyze corrosion levels, bond strength, steel bar properties, and failure loads. Results showed the control specimens exhibited little corrosion while uncoated bars experienced significant corrosion after exposure. In contrast, exudate/resin coated bars demonstrated a substantial reduction in corrosion, indicating the coating's inhibitory effects. Pull-out bond strength and maximum slip tests consistently revealed lower strengths and higher slips in corroded samples compared to controls. However, coated specimens maintained higher bond capacities and lower displacements, validating the coating's protective performance. Measurement of bar diameters, cross-sectional areas, and weights before and after corrosion highlighted the proportional losses associated with the corrosion process. Dimensions and masses of corroded reinforcements decreased by 2-7% on average from initial values. In comparison, controls showed minimal variations. Failure load analyses found controls withstood the highest loads, while corroded members exhibited reduced capacities. Overall, the study demonstrated corrosion negatively impacts the critical steel-concrete bond and undermines composite action essential for structural integrity. Exposure to NaCl solutions markedly increased corrosion and decomposition of unprotected bars. However, natural Canarium schweinfurthiia exudate/resin coatings were highly effective at mitigating corrosion effects by preserving bond strength, slip resistance, steel geometries and load capacities close to uncorroded levels. The findings validate protective coatings as a viable solution for durable reinforced concrete design in marine environments. Proper corrosion prevention through coatings or inhibitors can help ensure structures withstand service loads over their design life.

Cross-Sectional Area and Echogenicity Reference Values for Sonography of Peripheral Nerves in the Lithuanian Population.

We aimed to provide data of nerve sizes and echogenicity reference values of the Lithuanian population. High-resolution ultrasound was bilaterally performed according to the Ultrasound Pattern Sum Score and Neuropathy ultrasound protocols for healthy Lithuanian adults. Cross-sectional area (CSA) measurement and echogenicity were used as the main parameters for investigation. Echogenicity was evaluated using ImageJ, and nerves were categorized in classes according to echogenicity. Of 125 subjects enrolled, 63 were males (mean age 47.57 years, range 25-78 years) and 62 were females (mean age 50.50 years, range 25-80 years). Reference values of nerve sizes and values of echogenicity as a fraction of black in percentage of cervical roots, upper and middle trunks of the brachial plexus and the following nerves: vagal, median, ulnar, radial, superficial radial, tibial, fibular, and sural in standard regions were established. Mild to moderate correlations were found between nerves CSA, echogenicity values and anthropometric measurements with the differences according to sex. Inter-rater (ICC 0.93; 95% CI 0.92-0.94) and intra-rater (ICC 0.94; 95% CI 0.93-0.95) reliability was excellent. Reference values of nerve size and echogenicity of Lithuanians were presented for the first time as a novel such kind of publication from the Baltic countries.

Use of 3D-CT-derived psoas major muscle volume in defining sarcopenia in colorectal cancer

BackgroundSarcopenia is characterized by reduced skeletal muscle volume and is a condition that is prevalent among elderly patients and associated with poor prognosis as a comorbidity in malignancies. Given the aging population over 80 years old in Japan, an understanding of malignancies, including colorectal cancer (CRC), complicated by sarcopenia is increasingly important. Therefore, the focus of this study is on a novel and practical diagnostic approach of assessment of psoas major muscle volume (PV) using 3-dimensional computed tomography (3D-CT) in diagnosis of sarcopenia in patients with CRC.MethodsThe subjects were 150 patients aged ≥ 80 years with CRC who underwent primary tumor resection at Juntendo University Hospital between 2004 and 2017. 3D-CT measurement of PV and conventional CT measurement of the psoas major muscle cross-sectional area (PA) were used to identify sarcopenia (group S) and non-sarcopenia (group nS) cases. Clinicopathological characteristics, operative results, postoperative complications, and prognosis were compared between these groups.ResultsThe S:nS ratios were 15:135 for the PV method and 52:98 for the PA method. There was a strong positive correlation (r = 0.66, p < 0.01) between PVI (psoas major muscle volume index) and PAI (psoas major muscle cross-sectional area index), which were calculated by dividing PV or PA by the square of height. Surgical results and postoperative complications did not differ significantly in the S and nS groups defined using each method. Overall survival was worse in group S compared to group nS identified by PV (p < 0.01), but not significantly different in groups S and nS identified by PA (p = 0.77). A Cox proportional hazards model for OS identified group S by PV as an independent predictor of a poor prognosis (p < 0.05), whereas group S by PA was not a predictor of prognosis (p = 0.60).ConclusionsThe PV method for identifying sarcopenia in elderly patients with CRC is more practical and sensitive for prediction of a poor prognosis compared to the conventional method.

A Pilot Clinical and Technical Validation of an Immersive Virtual Reality Platform for 3D Anatomical Modeling and Contouring in Support of Surgical and Radiation Oncology Treatment Planning.

The aim of this study was to validate a novel medical virtual reality (VR) platform used for medical image segmentation and contouring in radiation oncology and 3D anatomical modeling and simulation for planning medical interventions, including surgery. The first step of the validation was to verify quantitatively and qualitatively that the VR platform can produce substantially equivalent 3D anatomical models, image contours, and measurements to those generated with existing commercial platforms. To achieve this, a total of eight image sets and 18 structures were segmented using both VR and reference commercial platforms. The image sets were chosen to cover a broad range of scanner manufacturers, modalities, and voxel dimensions. The second step consisted of evaluating whether the VR platform could provide efficiency improvements for target delineation in radiation oncology planning. To assess this, the image sets for five pediatric patients with resected standard-risk medulloblastoma were used to contour target volumes in support of treatment planning of craniospinal irradiation, requiring complete inclusion of the entire cerebral-spinal volume. Structures generated in the VR and the commercial platforms were found to have a high degree of similarity, with dicesimilarity coefficient ranging from 0.963 to 0.985 for high-resolution images and 0.920 to 0.990 for lower resolution images. Volume, cross-sectional area, and length measurements were also found to be in agreement with reference values derived from a commercial system, with length measurements having a maximum difference of 0.22mm, angle measurements having a maximum difference of 0.04°, and cross-sectional area measurements having a maximum difference of 0.16 mm2. The VR platform was also found to yield significant efficiency improvements, reducing the time required to delineate complex cranial and spinal target volumes by an average of 50% or 29min.

Reliability of Measuring Geniohyoid Cross-Sectional Area with B-Mode Ultrasound.

B-mode ultrasound is a safe noninvasive procedure that has been used to characterize aspects of the oropharyngeal swallow. The submental suprahyoid muscles are often investigated with ultrasound because of their contributions to hyolaryngeal elevation. There are several techniques for positioning the ultrasound transducer in the coronal plane, however, there is limited research on how reliability of measurement of the cross-sectional area (CSA) of the geniohyoid differs across transducer placement technique. This study examined three methods of transducer placement in the coronal plane by two examiners to determine the reliability of measurement of CSA of the geniohyoid muscle. Forty healthy adults participated in the study. Each participant's geniohyoid muscles were imaged using B-mode ultrasound under three transducer placement conditions in the coronal plane by two examiners. Geniohyoid CSA was measured from each ultrasound image. A three-way mixed-methods ANOVA was used to determine whether there were significant differences in geniohyoid CSA among transducer position conditions, trials, and examiners. There were significant differences among the transducer placement conditions, indicating that each condition was measuring a different portion of the muscle. There were no significant differences among repeated trials nor between examiners within each method of transducer placement. All three conditions of transducer placement were reliable at measuring geniohyoid CSA across trials and examiners. This study emphasizes the need for consistency of placement, whichever method is selected. It also highlights the need for researchers to provide a precise description of methods for positioning the transducer so that placement is reproducible.

Sonographic Measurement of Median Nerve Cross-Sectional Area to Determine Severity of Carpal Tunnel Syndrome: A Cautionary Tale.

Evaluate the diagnostic accuracy of median nerve cross-sectional area (CSA) to determine the severity of carpal tunnel syndrome (CTS) vs the presence of CTS across existing electrodiagnostic-based (EDX) classification systems. Retrospective analysis of cross-sectional patient data. Receiver operating characteristic (ROC) analysis was used to determine CSA cutoff values and associated diagnostic likelihood ratios for all consolidated and binary EDX-based classifications of CTS severity. Identification of CSA cutoff values associated with likelihood ratios capable of achieving conclusive (but at least moderate) shifts in diagnostic probability. Binary categorizations of CTS (ie, "Normal" vs "Absent") were statistically superior to consolidated categorizations of CTS severity (ie, "Normal," "Mild," "Moderate," or "Severe"). Binary categorizations established consistent CSA cutoff values across all EDX-based classifications examined and achieved conclusive shifts in diagnostic probability based on the following values of distal CSA or delta CSA: <7 or <1 mm2 to rule out and >13 or >7 mm2 to rule in CTS, respectively. Additionally, the following values of distal CSA and delta CSA may be used in certain circumstances because they produce only small shifts in diagnostic probability: ≤10 or ≤3 mm2 to rule out and ≥11 or ≥4 mm2 to rule in CTS, respectively. Using median nerve CSA to categorize the severity of CTS is not recommended based on lack of consistent and meaningful shifts in diagnostic probability. Rather, binary categorizations to rule out or rule in CTS based on the proposed CSA cutoff values consistently provided conclusive shifts in diagnostic probability across all EDX-based classifications examined.

Using a new artificial intelligence-aided method to assess body composition CT segmentation in colorectal cancer patients.

This study aimed to evaluate the accuracy of our own artificial intelligence (AI)-generated model to assess automated segmentation and quantification of body composition-derived computed tomography (CT) slices from the lumber (L3) region in colorectal cancer (CRC) patients. A total of 541 axial CT slices at the L3 vertebra were retrospectively collected from 319 patients with CRC diagnosed during 2012-2019 at a single Australian tertiary institution, Western Health in Melbourne. A two-dimensional U-Net convolutional network was trained on 338 slices to segment muscle, visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). Manual reading of these same slices of muscle, VAT and SAT was created to serve as ground truth data. The Dice similarity coefficient was used to assess the U-Net-based segmentation performance on both a validation dataset (68 slices) and a test dataset (203 slices). The measurement of cross-sectional area and Hounsfield unit (HU) density of muscle, VAT and SAT were compared between two methods. The segmentation for muscle, VAT and SAT demonstrated excellent performance for both the validation (Dice similarity coefficients >0.98, respectively) and test (Dice similarity coefficients >0.97, respectively) datasets. There was a strong positive correlation between manual and AI segmentation measurements of body composition for both datasets (Spearman's correlation coefficients: 0.944-0.999, P < 0.001). Compared to the gold standard, this fully automated segmentation system exhibited a high accuracy for assessing segmentation and quantification of abdominal muscle and adipose tissues of CT slices at the L3 in CRC patients.

Nerve cross-sectional area in advanced uremic neuropathy: A nerve ultrasound pilot study.

Uremic neuropathy (UN) is a disabling neuropathy in end-stage kidney disease (ESKD) affecting the majority of patients receiving long-term hemodialysis (HD). One previous nerve ultrasound study reported an increased cross-sectional area (CSA) of the median nerve in moderate UN, while another study found enlarged sural nerves in small-fiber polyneuropathy associated with ESKD. The present cohort study aims to analyze bilateral CSA of multiple nerves in UN. Ten nondiabetic ESKD patients with UN on HD for at least 2years and 10 healthy age-matched controls underwent bilateral ultrasound examinations with CSA measurements in 13 arm and leg nerve sites. Nerve conduction studies (NCS) and the total neuropathy score (TNS) were recorded. Pearson's coefficient and the Mann-Whitney U-test were used to analyze correlations and compare groups. ESKD patients presented advanced neuropathic symptoms (mean TNS 15.9). NCS showed significantly reduced motor and sensory amplitudes in the UN group compared to the control group, and a slightly reduced nerve CSA was observed in 5 of 13 nerve sites (p<.05); the other nerve sites were not enlarged. Sural nerve CSA (p<.05) and sensory amplitude (p<.01) were negatively correlated with the TNS. Nerve enlargement was not observed in the present study in advanced UN. A reduced nerve CSA observed in the sural nerve suggests an axonal loss associated with long-term HD in ESKD. During clinical workup of an acute disease of the peripheral nervous system in ESKD patients, nerve enlargement might be attributable to other causes than chronic UN.

Impact of Reduced Activity on Endurance of Rat Diaphragm Muscle

The diaphragm muscle (DIAm) as the major inspiratory pump is highly active. During breathing, fatigue resistant DIAm motor units are recruited that comprise type I and IIa fibers. Accordingly, these fibers have substantially higher mitochondrial volume density (MVD) and mitochondrial respiratory capacity (SDHmax) compared to more fatigable type IIx/IIb fibers. Cervical spinal cord injury disrupts descending inspiratory drive and markedly reduces eupneic activity of the DIAm. With C2 spinal cord hemisection (C2SH) DIAm activity on the ipsilateral side is reduced. Following a two-week period of C2SH, we found reduced MVD and SDHmax in type I and IIa DIAm fibers. As a result, we hypothesize that endurance of the DIAm is reduced. Female and male Sprague Dawley rats were used. EMG electrodes were placed in the left and right DIAm 3 days prior to C2SH surgery, and baseline recordings of eupneic DIAm activity were obtained in awake animals. The right C2 spinal cord was hemisected, and the extent of injury was confirmed by the absence of eupneic DIAm activity on the ipsilateral side while animals were anesthetized. Subsequently, DIAm EMG activity was recorded at 3, 7 and 14 days post C2SH. After two weeks, rats were anesthetized and the DIAm was excised. DIAm strips were cut and suspended in a tissue chamber containing Rees-Simpson solution maintained at 26oC, with thecostal margin clamped and the central tendon attached to a Cambridge Dual-Mode force/length transducer. DIAm strips were stimulated using platinum plate electrodes with supramaximal current (~250 mA) pulses (1 ms), and maximum specific force was determined at 75 Hz. The force-velocity relationship was then determined by systematically changing load, and maximum velocity (Vmax) was estimated based on curve fitting with the Hill-equation. Based on the force-velocity measurements peak power of the DIAm was calculated. Subsequently, the DIAm was repetitively stimulated and allowed to shorten at 30% maximum velocity (isovelocity approximating peak power output). Endurance of the DIAm was then determined as the duration that peak power output was sustained. Finally, the DIAm was rapidly frozen, and cross-sections were cut for fiber type and cross-sectional area (CSA) measurements. C2SH resulted in a marked decrease in eupneic DIAm EMG activity across the two-week period, which disproportionately affected type I and IIa DIAm fibers. However, there was no impact of C2SH on DIAm fiber type proportions or CSA. Following two-weeks C2SH, maximum specific force, Vmax, and peak power output of the DIAm were comparable between intact and injured sides. However, endurance of the DIAm was reduced on the injured side compared to the intact side. These results support our hypothesis that reduced activity of DIAm, reduces oxidative capacity of type I and IIa fibers and thereby reduces endurance. In clinical conditions such as mechanical ventilation DIAm activity is reduced and if maintained for longer periods of time this may affect DIAm endurance post weaning. Research supported by NIH grant: HL146114 (GCS). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Ultrasound-Guided Modified Thread Carpal Tunnel Release for Carpal Tunnel Syndrome: A Pilot Study.

This study aimed to investigate the effectiveness and safety of modified thread carpal tunnel release (mTCTR) using Smartwire-01 in patients with carpal tunnel syndrome (CTS). Patients with CTS who required CTR were enrolled. Symptom severity and functional status were assessed using the Boston Carpal Tunnel Syndrome Questionnaire-Symptom Severity Scale (BCTQ-SSS) and Functional Status Scale (BCTQ-FSS), and pain was assessed using a numerical rating scale (NRS) at 4, 8, and 12 weeks after mTCTR. The scores were compared with the pre-procedural scores. The electrophysiologic study and median nerve cross-sectional area (CSA) measurements at the wrist before and 12 weeks after mTCTR were compared. A total of 11 patients were included. No adverse effects were reported throughout the study period. The NRS, BCTQ-SSS, and BCTQ-FSS scores significantly improved at 4 weeks after mTCTR, and this improvement persisted throughout the follow-up period (NRS and BCTQ-SSS, P < 0.001; BCTQ-FSS, P = 0.012). After 12 weeks, the latency and velocity of the median sensory nerve action potential significantly improved, compared with those before mTCTR (latency, 5.4 ± 1.3 to 4.7 ± 1.1 ms, P = 0.01; velocity 27.8 ± 6.8 to 31.8 ± 7.4 m/s, P = 0.019). No significant change was observed in the median nerve CSA before and after mTCTR. mTCTR using Smartwire-01 is a safe and effective procedure and a possible alternative to surgery.

Cut-off value for a normal posterior tibial nerve to diagnose tarsal tunnel syndrome amongst people of different race in Pretoria, South Africa.

Posterior tibial nerve (PTN) cross-sectional area (CSA) reference values for the diagnosis of tarsal tunnel syndrome (TTS) using ultrasound imaging exist in several countries but not in South Africa (SA). Therefore, the objective was to measure the CSA reference values for PTN in SA. Ultrasound CSA measurements of PTN in both ankles on 112 participants were performed, the mean measurement was recorded, and the effect of race, age, gender, and body mass index (BMI) were recorded. In this study, the primary variables age and BMI affect the CSA measurement of the PTN. A positive correlation was found between PTN asymptomatic size and age (r = 0.196, P < 0.05), size and BMI (r = 0.200, P < 0.05). Age (categories) had a mean value of 3.17 for the age group 36-45 years (95% confidence interval (CI) 2.9-3.4). The mean BMI was 30.0 kg/m2 (CI 28.57-31.08). As for the asymptomatic PTN, a mean CSA reference value of 0.10 cm2 was obtained. With increase in age and BMI, a greater PTN measurement will occur. Race appears to be a contributing factor, but further research is needed in this regard. The reference CSA value for normal PTN should be set at 0.10 cm2 for all racial groups for a basic musculoskeletal ultrasound exam protocol in South Africa.

Improved inter-subject alignment of the lumbosacral cord for group-level in vivo gray and white matter assessments: A scan-rescan MRI study at 3T.

Magnetic resonance imaging (MRI) enables the investigation of pathological changes in gray and white matter at the lumbosacral enlargement (LSE) and conus medullaris (CM). However, conducting group-level analyses of MRI metrics in the lumbosacral spinal cord is challenging due to variability in CM length, lack of established image-based landmarks, and unknown scan-rescan reliability. This study aimed to improve inter-subject alignment of the lumbosacral cord to facilitate group-level analyses of MRI metrics. Additionally, we evaluated the scan-rescan reliability of MRI-based cross-sectional area (CSA) measurements and diffusion tensor imaging (DTI) metrics. Fifteen participants (10 healthy volunteers and 5 patients with spinal cord injury) underwent axial T2*-weighted and diffusion MRI at 3T. We assessed the reliability of spinal cord and gray matter-based landmarks for inter-subject alignment of the lumbosacral cord, the inter-subject variability of MRI metrics before and after adjusting for the CM length, the intra- and inter-rater reliability of CSA measurements, and the scan-rescan reliability of CSA measurements and DTI metrics. The slice with the largest gray matter CSA as an LSE landmark exhibited the highest reliability, both within and across raters. Adjusting for the CM length greatly reduced the inter-subject variability of MRI metrics. The intra-rater, inter-rater, and scan-rescan reliability of MRI metrics were the highest at and around the LSE (scan-rescan coefficient of variation <3% for CSA measurements and <7% for DTI metrics within the white matter) and decreased considerably caudal to it. To facilitate group-level analyses, we recommend using the slice with the largest gray matter CSA as a reliable LSE landmark, along with an adjustment for the CM length. We also stress the significance of the anatomical location within the lumbosacral cord in relation to the reliability of MRI metrics. The scan-rescan reliability values serve as valuable guides for power and sample size calculations in future longitudinal studies.

Correlative algorithm for determining the velocity of hot-rolled rod and wire using Cross-Section variations

Measuring the velocity of hot rod and wire during rolling is crucial for accurate control of rolling stands and blocks. To accomplish this, the velocity should be measured at strategically placed locations throughout the mill. The current state-of-the-art exhibits various techniques and methods for velocity measurement with their respective advantages and disadvantages, whereas measuring devices based on the Laser-Doppler principle are the most widely used.As part of the research and development of an eddy-current based cross-sectional area measurement, we observed variations in the cross-sectional area of rods and wires. These variations should be utilized for developing a correlative method for velocity measurement. Within the scope of this work, the implementation of a measuring system and the development of an algorithm is described. This algorithm has been applied to a real data set and evaluated, while also assessing the impact of influencing factors on the quality and accuracy of calculated rolled material velocity. Finally, it was successfully demonstrated that the developed solution approach works in practice and provides excellent results. Nevertheless, further validation is required and velocity determination needs to be compared with an independent reference to improve accuracy estimation.

Improving Osteoporosis Prediction Using Vertebral Bone Quality Score and Paravertebral Muscle Measurements From Lumbar MRI Scans.

Retrospective cohort. This study aims to use a novel method of combining vertebral bone quality score with paravertebral cross-sectional area measurements to improve the accuracy of predicting individuals with total hip T-scores <-2.5. Osteoporosis is a prevalent skeletal condition associated with decreased bone density and increased fracture risk. Dual-energy x-ray absorptiometry (DXA) is the conventional method for diagnosing osteoporosis, but it has limitations. Opportunistic osteoporosis screening techniques using lumbar magnetic resonance imaging (MRI), particularly the vertebral bone quality (VBQ) score, have shown promise. This study aims to improve the accuracy of predicting individuals with low total hip T-scores using a novel method that combines VBQ scores with paravertebral cross-sectional area (CSA) measurements. A retrospective cohort of 98 patients with DXA and lumbar MRI scans was analyzed. VBQ scores were calculated based on lumbar MRI images, and CSA measurements of paravertebral and psoas muscles were obtained. Threshold-based logistic regression was used to identify optimal thresholds for predicting total hip T-scores <-2.5. The combined model incorporating the VBQ score and paravertebral muscle percent achieved an accuracy of 96.9% for predicting total hip T-scores <-2.5, compared to 81.6% when using the VBQ score alone. Incorporating paravertebral muscle measurements significantly improved the accuracy of identifying osteoporotic individuals. The combination of VBQ score and paravertebral muscle measurements enhances the accuracy of predicting individuals with low total hip T-scores. Lumbar MRI scans provide valuable information beyond opportunistic osteoporosis screening, and the inclusion of paravertebral muscle measurements could aid in identifying at-risk individuals more accurately.

Measuring the tensile properties of Ti6Al4V fabricated by laser powder bed fusion: Influence of specimen dimensions

This study presents the mechanical characterization of vertical Ti6Al4V tensile specimens produced by laser powder bed fusion (LPBF) processing and then heat-treated according to AMS2801 standard. The surfaces were kept in the as-built condition for the evaluations. Three rectangular specimen geometries were considered, with a reduced section of 6 × 6 × 25, 3 × 3 × 12.5, and 1 × 1.5 × 7 mm3 respectively. The surface roughness, length-scale of the microstructure, and average microhardness were compared and found to be unaffected by part section, in the range of sizes explored. The non-destructive measurement of the cross-sectional area of the tested specimens affected the accuracy on the measurement of the tensile strength. The use of conventional tools, such as calipers and micrometers, led to an overestimation of the cross-sectional area by 7 to 15 %, which caused an underestimation of the tensile stresses. When calculating the stress with the cross-sectional area measured from computed tomography images, the Young’s modulus, yield strength and ultimate tensile strength were comparable for all geometries. However, the elongation at break was 9 % for the smallest specimens compared to 12 % for ASTM E8 coupons. The reduction of ductility was explained by a higher slimness ratio for smaller specimens, in addition to an increased effect of pores and the surface roughness. These results highlight the importance of using specimens representative of a part wall thickness when characterizing the mechanical properties of LPBF Ti6Al4V. The methodological recommendations established in this study can be applied to other LPBF materials and other small scale manufacturing processes.

Assessment of sonographic measurement of the median nerve cross-sectional area in pregnant women with hypertensive disorders

Assessment of sonographic measurement of the median nerve cross-sectional area in pregnant women with hypertensive disorders

Association between electrodiagnosis and neuromuscular ultrasound in the diagnosis and assessment of severity of carpal tunnel syndrome.

Neuromuscular ultrasound plays an increasing role in diagnosing carpal tunnel syndrome (CTS). There are limited data supporting the correlation between the electrodiagnostic studies and ultrasound measurements in CTS. To assess the association between different electrodiagnostic severities and ultrasound measurements of the median nerve in CTS. A retrospective cohort study. An academic tertiary care center. Patients 18 years or older evaluated with upper limb electrodiagnostic studies and neuromuscular ultrasound. Ultrasound measurements of the median nerve cross-sectional area (CSA) at the wrist and the calculated wrist-to-forearm ratio (WFR) were compared with the electrodiagnostic severity (normal, mild, moderate, and severe). Mean analysis and analysis of variance test (α = 0.05) were performed to assess the association. A total of 1359 limbs were identified. There was a statistically significant association between electrodiagnostic severity of CTS and median nerve CSA at the wrist (p < .001), as well as the WFR (p < .001). The mean median nerve CSA at the wrist and WFR were 7.01 ± 2.06 mm2 (95% CI: 6.80-7.20) and 1.24 ± 0.36 (95% CI: 1.16-1.24) in electrodiagnostically normal median nerves, 10.47 ± 2.82 mm2 (95% CI: 10.25-10.75) and 2.06 ± 0.67 (95% CI: 2.04-2.16) in electrodiagnostically mild CTS, 12.95 ± 4.74 mm2 (95% CI: 12.41-13.59) and 2.49 ± 1.04 (95% CI: 2.37, 2.63) in electrodiagnostically moderate CTS, and 14.69 ± 5.38 mm2 (95% CI: 13.95-15.44) and 2.71 ± 1.02 (95% CI: 2.56-2.84) in electrodiagnostically severe CTS, respectively. This study suggests a direct association between electrodiagnostic severity and ultrasound measurements of the median nerve in patients with suspected CTS.

Volumetric assessment of ulnar nerves in cubital tunnel syndrome with 3D modeling of the MRI and its relationship with electrodiagnostic findings

BackgroundThickened nerve cross-sectional areas (CSA) have been investigated in compressive neuropathy, but the longitudinal extent of nerve swelling has yet to be evaluated. We did a volumetric assessment of the ulnar nerve in cubital tunnel syndrome (CuTS) with three-dimensional (3D) magnetic resonance imaging (MRI) modeling and investigated this relationship with clinical and electrodiagnostic parameters. MethodsWe compared 40 CuTS patient elbow MRIs to 46 patient elbow MRIs with lateral elbow epicondylitis as controls. The ulnar nerve was modeled with Mimics software and was assessed qualitatively and quantitatively. The CSA and ulnar nerve volumes were recorded, and the area under the receiver operating characteristic (ROC) curve was calculated for diagnostic performance. We analyzed clinical and electrodiagnostic parameters to investigate their relationship with the 3D ulnar nerve parameters. ResultsFor the diagnosis of CuTS, the area under the curve value was 0.915 for the largest CSA and 0.910 for the volume in the ROC curve. The optimal cut-off was 14.53 mm2 and 529 mm3 respectively. When electrodiagnostic parameters were investigated, the 3D ulnar nerve volume was significantly inversely associated with motor conduction velocity, although there was no association between the largest CSA and any of the electrodiagnostic parameters. ConclusionsThe 3D ulnar nerve volume, which is an integration or multilevel measurement of CSAs, showed diagnostic usefulness similar to CSA, but it correlated better with conduction velocity, indicating demyelination or early-to-moderate nerve damage in CuTS.