Comparison of Short-Tau Inversion Recovery With Short-Tau Inversion Recovery-Slice Encoding for Metal Artifact Correction for Spine Imaging at 1.5 T in the Setting of Metallic Implants.

OBJECTIVE: To compare the image quality of short-tau inversion recovery (STIR) and the STIR-slice encoding for metal artifact correction (SEMAC) sequence for postsurgery spine magnetic resonance imaging (MRI). METHODS: Twenty-nine patients with metallic spinal implants who underwent spinal 1.5 T MRI with STIR and STIR-SEMAC sequences between July 2016 and November 2020 were retrospectively enrolled. Qualitative assessments were performed using 5-point scales; higher scores indicated better image quality. For screw metal artifact analysis, scores were obtained for artifacts on vertebral bodies and neural foramina, screw artifact widths, and bone marrow signal intensities. For patient-based analysis, scores were obtained for imaging quality and fat suppression quality, signal intensity, and cerebrospinal fluid noise. A paired t test was performed for statistical analyses. RESULTS: We analyzed 163 screws in 29 patients. In the screw metal artifact analysis, the vertebral body and neural foramen scores were significantly higher for the STIR-SEMAC images than for the STIR (all P < 0.001). The artifact width in the STIR-SEMAC images (9.8 ± 3.4 mm) was significantly smaller than that in the STIR images (16.0 ± 4.7 mm, P < 0.001). In patient-based analysis, the fat suppression and imaging quality scores were significantly higher for the STIR-SEMAC images than for the STIR images (all P < 0.001). The cerebrospinal fluid signal intensity, noise, and signal-to-noise ratios were significantly higher for the STIR images (all P < 0.005). CONCLUSIONS: Short-tau inversion recovery-SEMAC sequences provide good metallic artifact reduction and fat suppression for postsurgery spine 1.5 T MRI.

Feasibility of Arterial Spin Labeling Magnetic Resonance Imaging for Musculoskeletal Tumors with Optimized Post-Labeling Delay.

Arterial spin labeling (ASL) magnetic resonance imaging (MRI) is used to perform perfusion imaging without administration of contrast media. However, the reliability of ASL for musculoskeletal tumors and the influence of post-labeling delay (PLD) have not been fully clarified. This study aimed to evaluate the performance of ASL with different PLDs in the imaging of musculoskeletal tumors. Forty-five patients were enrolled and were divided into a malignant group, a hypervascular benign group, a hypovascular benign group and a control group. The tissue blood flow (TBF) of the lesions and normal muscles was measured and the lesion-to-muscle TBF ratio and differences were calculated. The results showed that both the TBF of lesions and muscles increased as the PLD increased, and the TBF of muscles correlated significantly and positively with the TBF of lesions (all p < 0.05). The TBF and lesion-to-muscle TBF differences of the malignant lesions were significantly higher than those of the hypovascular benign lesions and the control group in all PLD groups (all p < 0.0125) and only those of the hypervascular benign lesions in the longest PLD (3025 ms) group (p = 0.0120, 0.0116). In conclusion, ASL detects high TBF in malignant tumors and hypervascular benign lesions, and a longer PLD is recommended for ASL to differentiate musculoskeletal tumors.

The Effects of High-Intensity Power Training versus Traditional Resistance Training on Exercise Performance.

Background: High-intensity interval training (HIIT) features short, repeated bursts of relatively vigorous exercise with intermittent periods of rest or low-intensity exercise. High-intensity power training (HIPT), in combination with HIIT and traditional resistance training (TRT), is characterized as multijoint high-intensity resistance exercises with low interset rest periods. HIPT requires people to finish the exercise as fast as possible, which increases acute physiological demands. The aim of the study was to investigate the differences between eight-week HIPT or TRT on exercise performance. Methods: Twenty-four college students were recruited and randomly assigned to either the HIPT or TRT group in a counterbalanced order. The power of upper and lower limbs (50% 1RM bench press and vertical jump) and anaerobic power were tested before and after the training (weeks 0 and 9). The results were analyzed by two-way analysis of variance (ANOVA) or Friedman's test with a significance level of α = 0.05 to compare the effects of the intervention on exercise performance. Results: There were significant differences in the explosive force of the upper and lower limbs between the pretest and post-test in both the HIPT and TRT groups (p < 0.05). However, only the HIPT group showed a significant difference in the mean power on the Wingate anaerobic test between the pretest and post-test (p < 0.05). Conclusions: Both HIPT and TRT can improve upper and lower limb explosive force. HIPT is an efficient training protocol, which took less time and produced a better improvement in mean anaerobic power.

Reliability of Gradient-Echo Magnetic Resonance Elastography of Lumbar Muscles: Phantom and Clinical Studies.

Magnetic resonance elastography (MRE) has been used to successfully characterize the mechanical behavior of healthy and diseased muscles, but no study has been performed to investigate the reliability of MRE on lumbar muscles. The objective of this work was to determine the reliability of MRE techniques on lumbar muscles in both ex vivo phantom and in vivo human studies. In this study, fresh porcine leg muscles were used in the phantom study, and 80 healthy adults (38.6 ± 11.2 years, 40 women) were recruited in the human study. Five repeated stiffness maps were obtained from both the phantom and human muscles by using a gradient-echo MRE sequence with a pneumatic vibration on a 1.5 T MR scanner. The technical failure rate, coefficient of variation (CV), and quality score were assessed to evaluate the reliability of MRE, respectively. Analysis of variance was performed to compare the stiffness between different lumbar muscles, and the difference was significant if p < 0.05 after Bonferroni correction. The results showed that the MRE achieved a zero technical failure rate and a low CV of stiffness (6.24 ± 1.41%) in the phantom muscles. However, in the human study, the MRE exhibited high CVs of stiffness (21.57%−25.24%) in the lumbar muscles, and the technical failure rate was higher in psoas muscles (60.0−66.3% in) than in paraspinal muscles (0.0−2.5%). Further, higher quality scores were noticed in paraspinal muscles (7.31−7.71) than those in psoas muscles (1.83−2.06). In conclusion, the MRE was a reliable technique to investigate the mechanical property of lumbar muscles, but it was less reliable to assess stiffness in psoas muscles than paraspinal muscles.

Ten-year follow-up of renal adenomatosis with magnetic resonance imaging: a case report.

BACKGROUND: Renal adenomatosis is a rare disease that presents as multiple papillary adenomas in the bilateral kidneys. Moreover, papillary adenoma is considered a precursor to papillary renal cell carcinoma. Therefore, patients with renal adenomatosis may have higher risk of developing malignancy than patients without this benign condition. CASE PRESENTATION: We present the case of a 62-year-old Asian woman with past history of papillary thyroid cancer. She underwent contrast-enhanced magnetic resonance imaging of the abdomen to screen for metastasis in 2010 and was followed up with computed tomography or magnetic resonance imaging annually. She was found to have a right renal tumor on computed tomography and underwent partial nephrectomy. The pathological diagnosis of the right renal tumor was angiomyolipoma. Renal adenomatosis was also histologically confirmed in the renal parenchyma adjacent to the angiomyolipoma. In this case report, we demonstrate the natural course of renal adenomatosis over 10 years using imaging studies. The benign tumors gradually progressed during the follow-up period. Larger tumor sizes and more hypoenhanced nodules in the bilateral kidneys were observed on follow-up computed tomography and magnetic resonance imaging. CONCLUSIONS: Due to its malignant potential, the clinical course of renal adenomatosis must be monitored. We present the natural course of renal adenomatosis with magnetic resonance imaging during a 10-year follow-up period.

Prophylactic Intraoperative Uterine Artery Embolization During Cesarean Section or Cesarean Hysterectomy in Patients with Abnormal Placentation: A Systematic Review and Meta-Analysis.

PURPOSE: To evaluate the effectiveness and safety of prophylactic intraoperative uterine artery embolization (UAE) performed immediately after fetal delivery during planned cesarean section or cesarean hysterectomy in patients with placenta accreta spectrum disorder or placenta previa. METHODS: A systematic search was conducted on Ovid MEDLINE and Embase, PubMed, Web of Science, and Cochrane databases. Studies were selected using the Population/Intervention/Comparison/Outcomes (PICO) strategy. The intraoperative blood loss and the rate of emergent peripartum hysterectomy (EPH) were the primary outcomes, whereas the length of hospital stay and volume of blood transfused were the secondary outcomes. A random-effects model was employed to pool each effect size. The cumulative values of the primary outcomes were calculated using the generic inverse variance method. RESULTS: Eleven retrospective cohort studies and five case series were included, recruiting 421 women who underwent prophylactic intraoperative UAE (UAE group) and 374 women who did not (control group). Compared with the control group, the UAE group had significantly reduced intraoperative blood loss (p = 0.020) during cesarean section or cesarean hysterectomy. Furthermore, the EPH rate was also significantly decreased (p = 0.020; cumulative rate: 19.65%), but not the length of hospital stay (p = 0.850) and volume of pRBC transfused (p = 0.140), after cesarean section in the UAE group. The incidence of major complications was low (3.33%), despite two patients with uterine necrosis. CONCLUSION: The currently available data provides encouraging evidence that prophylactic intraoperative UAE may contribute to hemorrhage control and fertility preservation in women with abnormal placentation. REGISTRATION: PROSPERO registration code: CRD42021230581. https://clinicaltrials.gov/ct2/show/CRD42021230581 LEVEL OF EVIDENCE: Level 2a, systematic review of retrospective cohort studies.

Effects of 4-Week Inspiratory Muscle Training on Sport Performance in College 800-Meter Track Runners.

Background and objectives: Respiratory muscle fatigue is one of the important factors limiting sports performance due to the metaboreflex. This reflex will cause a decrease in blood flow to the extremities and accelerate exercising limb fatigue. Previous studies found that inspiratory muscle training (IMT) can effectively enhance the respiratory muscle endurance and reduce fatigue during long-duration exercise or aerobic exercise, thereby enhancing athletic performance. However, the mechanism between inspiratory muscle strength, change of limb blood flow and sports performance still requires investigation, especially in short-duration exercise, anaerobic or both aerobic and anaerobic exercise. The purpose of this study was to investigate the effects of 4-week inspiratory muscle training on respiratory muscle strength, limb blood flow change rate and sports performance in recreational 800-m college runners. Materials and Methods: Twenty healthy 800-m college runners randomized into the IMT group (11 subjects) and control group (9 subjects). IMT consisted of 30 inspiratory efforts twice daily, 5 days a week, with intensity at 50%, 60%, 70% and 80% of maximum inspiratory pressure (MIP) for 4 weeks, while a control group kept 50% of MIP for 4 weeks. An 800-m trial test, limb blood flow change rate by using Impedance Plethysmography, and MIP were as the outcome measured variables and be evaluated. All measured variables were assessed before and after 4-week IMT training. Two-way ANOVA was conducted for statistical analysis. Results: The results showed significantly interaction between groups and pre-posttest. IMT group significantly decreased limb blood flow change rate from 19.91 ± 11.65% to 9.63 ± 7.62% after received the IMT training program (p < 0.05). The MIP significantly improved from 112.95 ± 27.13 cmH2O to 131.09 ± 28.20 cm H2O in IMT group, and the 800-m trial test also shorted the running time from 162.97 ± 24.96 s to 156.75 ± 20.73 s. But the control group no significantly changed in MIP and 800-m trial test. Conclusions: Our results indicated that the 4-week IMT training (twice a day, 5 days a week) significantly improves participants' inspiratory muscle strength, 800-m running performance and decreases the limb blood flow change rate.

A novel Au/electroactive poly(amic acid) composite as an effective catalyst for p-nitrophenol reduction.

A Au/electroactive poly(amic acid) (Au/EPAA) composite was synthesized and characterized, and its catalytic ability was evaluated. EPAA was synthesized via oxidative coupling polymerization and Au nanoparticles were anchored to the amino and carboxyl groups. The Au/EPAA composite was characterized via X-ray diffraction analysis, X-ray photoelectron spectroscopy, and scanning electron microscopy, which confirmed that the Au nanoparticles were well dispersed on the EPAA surface. p-Nitrophenol was reduced to p-aminophenol within 5 min at room temperature, with a rate constant of 0.84 min-1. Cycling measurements showed that the Au/EPAA composite achieved higher than 92% conversion. The Au/EPAA composite showed excellent performance and stability as a catalyst for the reduction of p-nitrophenol to p-aminophenol.

A Novel Electroactive Imide Oligomer and Its Application in Anticorrosion Coating.

A novel aniline tetramer (AT) capped electroactive imide oligomer (EIO) for metal corrosion protection was successfully synthesized in this study. The chemical structure of the EIO was characterized by liquid chromatography-mass spectrometry and Fourier-transform infrared spectroscopy. Furthermore, the redox behavior of EIO was identified using electrochemical cyclic voltammetry studies. An EIO coated on a cold-rolled steel (CRS) electrode was found to possess superior corrosion resistance to polyimide (PI) on a series of electrochemical corrosion measurements in 3.5 wt.% NaCl solution over an extended period (30 days). The mechanism for the advanced corrosion protection of the PI coating on the CRS electrode could be attributed to the redox catalytic capabilities of the AT units present in the EIO. These capabilities may induce the formation of passive metal oxide layers on the CRS electrode. Scanning electron microscopy and X-ray photoelectron spectroscopy were used to analyze the surface condition of the CRS after the corrosion test. EIO- and PI-coated electrodes were identified by a series of electrochemical measurements, including corrosion potential (Ecorr), polarization resistance (Rp), and corrosion current (Icorr) measurements, along with electrochemical impedance spectroscopy (EIS).

Application of electroactive Au/aniline tetramer-graphene oxide composites as a highly efficient reusable catalyst.

This study proposes a cost-effective, energy-saving, and green process that uses π-π interactions to modify graphene oxide (GO), and the conjugate structure of aniline tetramer (AT) to enhance the dispersion of GO. Au/aniline tetramer-graphene oxide (Au/ATGO) composites were synthesized and applied as a catalyst in this study. The adsorption of AT on GO, via π-π interaction, formed ATGO composites. Subsequently, the amine group on ATGO was stably anchored on Au nanoparticles (Au NPs) to form Au/ATGO composites. The Au/ATGO composites were characterized and the electroactive properties determined by Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, and cyclic voltammetry. The Au/ATGO composites showed excellent performance and stability as catalysts when applied for the reduction of nitrophenol to aminophenol within 225 s and the rate constant was 0.02 s-1. The activation energy for the reduction of 4-NP and 2-NP was 48.10 and 68.71 kJ mol-1, respectively. Following a recycling test repeated 20 times, the Au/ATGO composites maintained a conversion rate higher than 94%.

Gadoxetic acid-enhanced magnetic resonance imaging can predict the pathologic stage of solitary hepatocellular carcinoma.

BACKGROUND: Although important for determining long-term outcome, pathologic stage of hepatocellular carcinoma (HCC) is difficult to predict before surgery. Current state-of-the-art magnetic resonance imaging (MRI) using gadoxetic acid provides many imaging features that could potentially be used to classify single HCC as pT1 or pT2. AIM: To determine which gadoxetic acid-enhanced MRI (EOB-MRI) findings predict pathologic stage T2 in patients with solitary HCC (cT1). METHODS: Pre-operative EOB-MRI findings were reviewed in a retrospective cohort of patients with solitary HCC. The following imaging features were examined: Hyperintensity in unenhanced T2-weighted images, hypointensity in unenhanced T1-weighted images, arterial enhancement, corona enhancement, washout appearance, capsular appearance, hypointensity in the tumor tissue during the hepatobiliary (HB) phase, peritumoral hypointensity in the HB phase, hypointense rim in the HB phase, intratumoral fat, hyperintensity on diffusion-weighted imaging, hypointensity on apparent diffusion coefficient map, mosaic appearance, nodule-in-nodule appearance, and the margin (smooth or irregular). Surgical pathology was used as the reference method for tumor staging. Univariate and multivariate analyses were performed to identify predictors of microvascular invasion or satellite nodules. RESULTS: There were 39 (34.2%; 39 of 114) and 75 (65.8%; 75 of 114) pathological stage T2 and T1 HCCs, respectively. Large tumor size (≥ 2.3 cm) and two MRI findings, i.e., corona enhancement [odds ratio = 2.67; 95% confidence interval: 1.101-6.480] and peritumoral hypointensity in HB phase images (odds ratio = 2.203; 95% confidence interval: 0.961-5.049) were associated with high risk of pT2 HCC. The positive likelihood ratio was 6.25 (95% confidence interval: 1.788-21.845), and sensitivity of EOB-MRI for detecting pT2 HCC was 86.2% when two or three of these MRI features were present. Small tumor size and hypointense rim in the HB phase were regarded as benign features. Small HCCs with hypointense rim but not associated with aggressive features were mostly pT1 lesions (specificity, 100%). CONCLUSION: Imaging features on EOB-MRI could potentially be used to predict the pathologic stage of solitary HCC (cT1) as pT1 or pT2.

The influence of heel height on frontal plane ankle biomechanics: implications for lateral ankle sprains.

BACKGROUND: Wearing high heel shoes is thought to increase an individual's likelihood of experiencing a lateral ankle sprain. The purpose of this study was to evaluate the influence of heel height on frontal plane kinematics, kinetics, and electromyographic (EMG) activity of the ankle joint during walking. METHODS: Eighteen healthy women participated. Three-dimensional kinematics, ground reaction forces, and EMG signals of the tibialis anterior (TA) and peroneus longus (PL) were recorded as subjects ambulated in high (9.5~cm) and low (1.3~cm) heel shoes at a self-selected walking velocity. Peak ankle plantarflexion, peak ankle inversion angle, and the peak ankle inversion moment during the stance phase of gait were evaluated. The EMG variables of interest consisted of the normalized average signal amplitude of the TA and PL during the first 50% of the stance phase. Paired t-tests were used to assess differences between the two shoe conditions. RESULTS: When compared to the low heel condition, wearing high heels resulted in significantly greater peak ankle plantarflexion and inversion angles (p < 0.001). In addition, the peak inversion moment and PL muscle activation was found to be significantly higher in the high heel condition (p < 0.001). No difference in TA muscle activity was found between shoe conditions (p = 0.30). CONCLUSION: The plantarflexed and inverted posture when wearing high heels may increase an individual's risk for experiencing a lateral ankle sprain. CLINICAL RELEVANCE: Data obtained from this investigation highlights the need for increased awareness and proper education related to the wearing of high heel shoes.

Comparatively electrochemical studies at different operational temperatures for the effect of layered silicate and spherical silica on the anticorrosion efficiency of PANI nanocomposite coatings.

In this paper, a series of PANI nanocomposites have been successfully prepared by in situ oxidative polymerization. The as-prepared PANI nanocomposites were subsequently characterized by WAXRD patterns and TEM. It should be noted that the nanocomposite coating containing 3 wt-% of organophilic clay loading was found to exhibit an observable enhanced corrosion protection on cold-rolled steel (CRS) electrode at higher operational temperature of 50 degrees C, which was even better than that of uncoated and electrode-coated with PANI or PANI nanocomposites with 3 wt-% of amino-modified silica nanoparticles alone at room temperature of 30 degrees C based on the electrochemical parameter evaluations (e.g., E(corr), R(p), I(corr), R(corr) and impedance). The vapor permeability property at three different operational temperatures of PANI and PANI nanocomposite membranes were investigated by vapor permeability analyzer (VPA). Effect of material composition on the molecular weight, optical properties and surface hydrophobicity of neat PANI and PANI nanocomposite, in the form of membrane and solution, were studied by gel permeation chromatography (GPC), ultraviolet-visible absorption spectra and contact-angle measurements, respectively. Finally, electrical conductivity at three different operational temperatures of PANI and PANI nanocomposite powder-pressed pellets was also investigated through the measurements of standard four-point-probe technique.