Water phase transition and signal nulling in 3D dual-echo adiabatic inversion-recovery UTE (IR-UTE) imaging of myelin.

PURPOSE: The semisolid myelin sheath has very fast transverse relaxation and is invisible to conventional MRI sequences. UTE sequences can detect signal from myelin. The major challenge is the concurrent detection of various water components. METHODS: The inversion recovery (IR)-based UTE (IR-UTE) sequence employs an adiabatic inversion pulse to invert and suppress water magnetizations. TI plays a key role in water suppression, with negative water magnetizations (negative phase) before the null point and positive water magnetizations (positive phase) after the null point. A series of dual-echo IR-UTE images were acquired with different TIs to detect water phase transition. The effects of TR in phase transition and water suppression were also investigated using a relatively long TR of 500 ms and a short TR of 106 ms. The water phase transition in dual-echo IR-UTE imaging of myelin was investigated in five ex vivo and five in vivo human brains. RESULTS: An apparent phase transition was observed in the second echo at the water signal null point, where the myelin signal was selectively detected by the UTE data acquisition at the optimal TI. The water phase transition point varied significantly across the brain when the long TR of 500 ms was used, whereas the convergence of TIs was observed when the short TR of 106 ms was used. CONCLUSION: The results suggest that the IR-UTE sequence with a short TR allows uniform inversion and nulling of water magnetizations, thereby providing volumetric imaging of myelin.

Current perspectives on mesenchymal stem cells as a potential therapeutic strategy for non-alcoholic fatty liver disease.

Non-alcoholic fatty liver disease (NAFLD) has emerged as a significant health challenge, characterized by its widespread prevalence, intricate natural progression and multifaceted pathogenesis. Although NAFLD initially presents as benign fat accumulation, it may progress to steatosis, non-alcoholic steatohepatitis, cirrhosis, and hepatocellular carcinoma. Mesenchymal stem cells (MSCs) are recognized for their intrinsic self-renewal, superior biocompatibility, and minimal immunogenicity, positioning them as a therapeutic innovation for liver diseases. Therefore, this review aims to elucidate the potential roles of MSCs in alleviating the progression of NAFLD by alteration of underlying molecular pathways, including glycolipid metabolism, inflammation, oxidative stress, endoplasmic reticulum stress, and fibrosis. The insights are expected to provide further understanding of the potential of MSCs in NAFLD therapeutics, and support the development of MSC-based therapy in the treatment of NAFLD.

Correlation between tumor budding and the long-term follow-up outcomes after endoscopic submucosal dissection for superficial esophageal squamous cell carcinoma.

BACKGROUND: The effect of tumor budding (TB) on the prognosis of patients with esophageal squamous cell carcinoma (ESCC) after endoscopic submucosal dissection (ESD) remains unclear. We evaluated the long-term outcomes of patients with superficial ESCC after ESD and the risk factors of TB for the long-term prognosis. METHODS: We conducted a retrospective study in a Chinese hospital. All patients with ESCC treated by ESD and reported TB were included consecutively. Comparative analyses were conducted in three parts: specimen analysis, follow-up analyses of unmatched patients, and propensity score-matched (PSM) patients. Cox proportional hazard regression models were constructed to identify risk factors for overall survival and recurrence-free survival (RFS). RESULTS: A total of 437 patients were enrolled [154 TB and 283 no tumor budding (NTB)], and 258 patients (52 TB and 206 NTB) were included in the follow-up analysis. Results showed that the invasion depth, differentiation type, and positive vascular invasion (all p < 0.001) of the TB group were significantly different from the NTB group. The all-cause mortality and the median RFS time between the two groups were comparable. RFS rate at 5 years were 84.6% and 80.6%, respectively (p = 0.43). Cox analyses identified that having other cancers but not TB, as a risk factor independently associated with overall survival and RFS after ESD. CONCLUSION: TB tends to be associated with invasion depth, differentiation type, and positive vascular invasion. However, it might not affect the long-term outcomes of patients with superficial ESCC after ESD when other high-risk factors are negative.

Association of Fine Particulate Matter and Residential Greenness With Risk of Pulmonary Tuberculosis Retreatment: Population-Based Retrospective Study.

Background: The evidence on the association of fine particulate matter with an aerodynamic diameter of 2.5 µm or less (PM2.5) with pulmonary tuberculosis (PTB) retreatment is limited. There are no data on whether greenness exposure protects air pollution-related PTB retreatment in patients with prior PTB. Objective: In a population-based retrospective study, we aimed to investigate the influence of PM2.5 and residential greenness on the risk of PTB retreatment. Methods: A total of 26,482 patients with incident PTB, registered in a mandatory web-based reporting system between 2012 and 2019 in Zhengzhou, China, were included in the analysis. The exposure to PM2.5 was assessed based on the China High Air Pollutants dataset, and the level of greenness was estimated using the Normalized Difference Vegetation Index (NDVI) values. The associations of PTB retreatment with exposure to PM2.5 and greenness were evaluated, respectively, considering the local socioeconomic level indicated by the nighttime light index. Results: Among the 26,482 patients (mean age 46.86, SD 19.52 years) with a median follow-up time of 1523 days per patient, 1542 (5.82%) PTB retreatments were observed between 2012 and 2019. Exposure to PM2.5 was observed to be significantly associated with the increased risk of PTB retreatment in fully adjusted models with a hazard ratio of 1.97 (95% CI 1.34-2.83) per 10 µg/m3 increase in PM2.5. Patients living in the regions with relatively high quartiles of NDVI values had a 45% lower risk of PTB retreatment than those living in the regions with the lowest quartile for the 500 m buffers (hazard ratio 0.55, 95% CI 0.40-0.77). Such a protective effect of residential greenness was more pronounced among patients living in lower nighttime light areas. The strength of the association between PM2.5 exposure and the risk of PTB retreatment was attenuated by greenness. No significant association was observed between NDVI and the incidence of drug resistance. Conclusions: Long-term exposure to PM2.5 might be a risk factor for PTB retreatment, while an increased level of residential greenness was found to be associated with reduced risks of PTB retreatment. Our results suggest strengthening the control of ambient air pollution and improving residential greenness may contribute to the reduction of PTB retreatment.

Towards assessing and improving the reliability of ultrashort echo time quantitative magnetization transfer (UTE-qMT) MRI of cortical bone: In silico and ex vivo study.

OBJECTIVE: To assess and improve the reliability of the ultrashort echo time quantitative magnetization transfer (UTE-qMT) modeling of the cortical bone. MATERIALS AND METHODS: Simulation-based digital phantoms were created that mimic the UTE-qMT properties of cortical bones. A wide range of SNR from 25 to 200 was simulated by adding different levels of noise to the synthesized MT-weighted images to assess the effect of SNR on UTE-qMT fitting results. Tensor-based denoising algorithm was applied to improve the fitting results. These results from digital phantom studies were validated via ex vivo rat leg bone scans. RESULTS: The selection of initial points for nonlinear fitting and the number of data points tested for qMT analysis have minimal effect on the fitting result. Magnetization exchange rate measurements are highly dependent on the SNR of raw images, which can be substantially improved with an appropriate denoising algorithm that gives similar fitting results from the raw images with an 8-fold higher SNR. DISCUSSION: The digital phantom approach enables the assessment of the reliability of bone UTE-qMT fitting by providing the known ground truth. These findings can be utilized for optimizing the data acquisition and analysis pipeline for UTE-qMT imaging of cortical bones.

Exploring the interplay between addiction and time perception: A systematic review and meta-analysis.

Prior studies have investigated the immediate impacts of substances on temporal perception, the impact of temporal outlook, and the consequences of modified temporal perception on addictive behaviors. These inquiries have provided valuable perspectives on the intricate associations between addiction and time perception, enriching the groundwork for forthcoming research and therapeutic strategies. This comprehensive review aims to further explore intricate correlation among diverse addictive substances-namely alcohol, cannabis, nicotine, opioids-and non-substance addictions such as internet gaming, elucidating their influence on temporal perception. Adhering to the PICOS method and adhering to PRISMA guidelines, we systematically reviewed and critically evaluated all existing research concerning temporal perception in individuals with substance and non-substance use disorders. Specifically, our analyses involved 31 pertinent articles encompassing six unique groups-alcohol, nicotine, cannabis, stimulants, opioids, and internet-related addictions-sourced from a pool of 551 papers. The findings revealed differences in time perception between addicts and control groups, as indicated by medium to large effect sizes (Hedge's g = 0.8, p < 0.001). However, the nature of these differences-whether they predominantly involve time overestimation or underestimation-is not yet definitively clear. This variability underscores the complexity of the relationship between addiction and temporal perception, paving the way for further research to unravel these intricate dynamics.

Metabolomics efficiently discriminates monozygotic twins in peripheral blood.

Monozygotic (MZ) twins cannot be distinguished using conventional forensic STR typing because they present identical STR genotypings. However, MZ twins do not always live in the same environment and often have different dietary and other lifestyle habits. Metabolic profiles are deyermined by individual characteristics and are also influenced by the environment in which they live. Therefore, they are potential markers capable of identifying MZ twins. Moreover, the production of proteins varies from organism to organism and is influenced by both the physiological state of the body and the external environment. Hence, we used metabolomics and proteomics to identify metabolites and proteins in peripheral blood to discriminate MZ twins. We identified 1749 known metabolites and 622 proteins in proteomic analysis. The metabolic profiles of four pairs of MZ twins revealed minor differences in intra-MZ twins and major differences in inter-MZ twins. Each pair of MZ twins exhibited distinct characteristics, and four metabolites-methyl picolinate, acesulfame, paraxanthine, and phenylbenzimidazole sulfonic acid-were observed in all four MZ twin pairs. These four differential exogenous metabolites conincidently show that the different external environments and life styles can be well distinguished by metabolites, considering that twins do not all have the same eating habits and living environments. Moreover, MZ twins showed different protein profiles in serum but not in whole blood. Thus, our results indicate that differential metabolites provide potential biomarkers for the personal identification of MZ twins in forensic medicine.

Neutrophil-Mediated Nanozyme Delivery System for Acute Kidney Injury Therapy.

Reactive oxygen species (ROS) scavenging of nanozymes toward acute kidney injury (AKI) is a current promising strategy, however, the glomerular filtration barrier (GFB) limits their application for treating kidney related diseases. Here, a neutrophil-mediated delivery system able to hijack neutrophil to transport nanozyme-loaded cRGD-liposomes to inflamed kidney for AKI treatment by cRGD targeting integrin αvß1 is reported. The neutrophil-mediated nanozyme delivery system demonstrated great antioxidant and anti-apoptosis ability in HK-2 and NRK-52E cell lines. Moreover, in ischemia-reperfusion (I/R) induced AKI mice, a single dose of LM@cRGD-LPs 12 h post-ischemia significantly reduces renal function indicators, alleviates renal pathological changes, and inhibits apoptosis of renal tubular cells and the expression of renal tubular injured marker, thus remarkably reducing the damage of AKI. Mechanistically, the treatment of LM@cRGD-LPs markedly inhibits the process of Nrf2 to the nucleus and reduces the expression of the downstream HO-1, achieves a 99.51% increase in renal tissue Nrf2 levels, and an 86.31% decrease in HO-1 levels after LM@cRGD-LPs treatment. In short, the strategy of neutrophil-mediated nanozyme delivery system hold great promise as a potential therapy for AKI or other inflammatory diseases.

Yet more evidence that non-aqueous myelin lipids can be directly imaged with ultrashort echo time (UTE) MRI on a clinical 3T scanner: a lyophilized red blood cell membrane lipid study.

Direct imaging of semi-solid lipids, such as myelin, is of great interest as a noninvasive biomarker of neurodegenerative diseases. Yet, the short T2 relaxation times of semi-solid lipid protons hamper direct detection through conventional magnetic resonance imaging (MRI) pulse sequences. In this study, we examined whether a three-dimensional ultrashort echo time (3D UTE) sequence can directly acquire signals from membrane lipids. Membrane lipids from red blood cells (RBC) were collected from commercially available blood as a general model of the myelin lipid bilayer and subjected to D2O exchange and freeze-drying for complete water removal. Sufficiently high MR signals were detected with the 3D UTE sequence, which showed an ultrashort T2* of ∼77-271 µs and a short T1 of ∼189 ms for semi-solid RBC membrane lipids. These measurements can guide designing UTE-based sequences for direct in vivo imaging of membrane lipids.

Circulation pattern and genetic variation of rhinovirus infection among hospitalized children on Hainan Island, before and after the dynamic zero-COVID policy, from 2021 to 2023.

Throughout the COVID-19 pandemic, rhinovirus (RV) remained notable persistence, maintaining its presence while other seasonal respiratory viruses were largely suppressed by pandemic restrictions during national lockdowns. This research explores the epidemiological dynamics of RV infections among pediatric populations on Hainan Island, China, specifically focusing on the impact before and after the zero-COVID policy was lifted. From January 2021 to December 2023, 19 680 samples were collected from pediatric patients hospitalized with acute lower respiratory tract infections (ARTIs) at the Hainan Maternal and Child Health Hospital. The infection of RV was detected by tNGS. RV species and subtypes were identified in 32 RV-positive samples representing diverse time points by analyzing the VP4/VP2 partial regions. Among the 19 680 pediatric inpatients with ARTIs analyzed, 21.55% were found to be positive for RV infection, with notable peaks observed in April 2021 and November 2022. A gradual annual decline in RV infections was observed, alongside a seasonal pattern of higher prevalence during the colder months. The highest proportion of RV infections was observed in the 0-1-year age group. Phylogenetic analysis on 32 samples indicated a trend from RV-A to RV-C in 2022. This observation suggests potential evolving dynamics within the RV species although further studies are needed due to the limited sample size. The research emphasizes the necessity for ongoing surveillance and targeted management, particularly for populations highly susceptible to severe illnesses caused by RV infections.

Green synthesis of zinc oxide nanoparticles from Sida acuta leaf extract for antibacterial and antioxidant applications, and catalytic degradation of dye through the use of convolutional neural network.

This study synthesized zinc oxide nanoparticles (ZnO NPs) using a novel green approach, with Sida acuta leaf extract as a capping and reducing agent to initiate nucleation and structure formation. The innovation of this study lies in demonstrating the originality of utilizing zinc oxide nanoparticles for antibacterial action, antioxidant potential, and catalytic degradation of Congo red dye. This unique approach harnesses eco-friendly methods to initiate nucleation and structure formation. The synthesized nanoparticles' structure and conformation were characterized using UV-vis (λmax = 280 nm), X-ray, atomic force microscopy, SEM, HR-TEM and FTIR. The antibacterial activity of the Nps was tested against Pseudomonas sp, Klebsiella sp, Staphylococcus aureus, and E. coli, demonstrating efficacy. The nanoparticles exhibited unique properties, with a crystallite size of 20 nm (XRD), a surface roughness of 2.5 nm (AFM), and a specific surface area of 60 m2/g (SEM). A Convolutional Neural Network (CNN) was effectively employed to accurately classify and analyze microscopic images of green-synthesized zinc oxide nanoparticles. This research revealed their exceptional antioxidant potential, with an average DPPH scavenging rate of 80% at a concentration of 0.05 mg/mL. Additionally, zeta potential measurements indicated a stable net negative surface charge of approximately -12.2 mV. These quantitative findings highlight the promising applications of green-synthesized ZnO NPs in healthcare, materials science, and environmental remediation. The ZnO nanoparticles exhibited catalytic capabilities for dye degradation, and the degradation rate was determined using UV spectroscopy. Key findings of the study encompass the green synthesis of versatile zinc oxide nanoparticles, demonstrating potent antibacterial action, antioxidant capabilities, and catalytic dye degradation potential. These nanoparticles offer multifaceted solutions with minimal environmental impact, addressing challenges in various fields, from healthcare to environmental remediation.

3D inversion recovery ultrashort echo time MRI can detect demyelination in cuprizone-treated mice.

Purpose: To test the ability of inversion-recovery ultrashort echo time (IR-UTE) MRI to directly detect demyelination in mice using a standard cuprizone mouse model. Methods: Non-aqueous myelin protons have ultrashort T2s and are "invisible" with conventional MRI sequences but can be detected with UTE sequences. The IR-UTE sequence uses an adiabatic inversion-recovery preparation to suppress the long T2 water signal so that the remaining signal is from the ultrashort T2 myelin component. In this study, eight 8-week-old C57BL/6 mice were fed cuprizone (n = 4) or control chow (n = 4) for 5 weeks and then imaged by 3D IR-UTE MRI. The differences in IR-UTE signal were compared in the major white matter tracts in the brain and correlated with the Luxol Fast Blue histochemical marker of myelin. Results: IR-UTE signal decreased in cuprizone-treated mice in white matter known to be sensitive to demyelination in this model, such as the corpus callosum, but not in white matter known to be resistant to demyelination, such as the internal capsule. These findings correlated with histochemical staining of myelin content. Conclusions: 3D IR-UTE MRI was sensitive to cuprizone-induced demyelination in the mouse brain, and is a promising noninvasive method for measuring brain myelin content.

Effect of vinegar supplementation on patients with esophageal lesions lightly stained with Lugol's iodine solution: Prospective single-centre trial.

BACKGROUND: Esophageal chromoendoscopy with iodine solution is important for detecting early esophageal cancer. The effect of routine treatment for lesions lightly stained with Lugol's iodine solution is limited, and the addition of natural substances to a regular diet is becoming increasingly common. Vinegar has antitumor effects as reported in previous studies. AIM: To evaluate whether vinegar supplementation could improve the prognosis of patients with lightly stained esophageal lesions. METHODS: This prospective single-centre trial included consecutive patients with lightly stained lesions between June 2020 and April 2022. Patients in the experimental group received increased amounts of vinegar for 6 months. The primary outcome of the study was the clinical therapeutic effect. Complications related to vinegar ingestion and adverse events were also recorded in detail. RESULTS: A total of 166 patients were included in the final analysis. There was no significant difference in the baseline data between the two groups. Intention-to-treat (ITT) analysis demonstrated that the rates at which endoscopic characteristics improved were 33.72% in the experimental group and 20.00% in the conventional group (P = 0.007); and the rates at which biopsy pathology improved were 19.77% and 8.75%, respectively (P = 0.011). Additional vinegar consumption had a statistically protective effect on the rate at which endoscopic characteristics improved [hazard ratio (HR) ITT = 2.183, 95%CI: 1.183-4.028; HRper-protocol (PP) = 2.307, 95%CI: 1.202-4.426] and biopsy pathology improved (HRITT = 2.931, 95%CI: 1.212-7.089; HRPP = 3.320, 95%CI: 1.295-8.507). No statistically significant effect of increased vinegar consumption on preventing high-grade intraepithelial neoplasia or early cancer was observed (HRITT = 0.382, 95%CI: 0.079-1.846; HRPP = 0.382, 95%CI: 0.079-1.846). The subgroup analyses indicated that the overall therapeutic improvement of endoscopic characteristics and biopsy pathology seemed more obvious in older (age > 60) male patients with small lesions (lesion size ≤ 0.5 cm). Three patients in the experimental group reported acid regurgitation and heartburn. No adverse event during gastroscopy were recorded during follow-up. CONCLUSION: A moderately increased ingestion of vinegar could not directly reduce the risk of esophageal cancer in the mucosa dysplasia population, but it improved the endoscopic characteristics and ameliorated the biopsy pathology to a certain extent. Further research is needed to verify the effect of nutritional intervention on precancerous esophageal lesions.

Ossifying fibromyxoid tumor of the soft tissue in the left upper arm and a review of the literature: A case report.

Ossifying fibromyxoid tumor (OFMT) of the soft parts is a mesenchymal neoplasm of uncertain lineage. Fibromyxoid matrix and peripheral metaplastic bone are common histological features of this type of tumor. In the present study, a case of OFMT in a 33-year-old female was reported. The patient was referred to the First Affiliated Hospital of China Medical University (Shenyan, China) in January 2018. The patient had developed a mass in the left upper arm 6 months prior to presentation, which was slowly enlarging. The tumor was 1.5 cm in diameter, with hard texture. Histologically, the tumor showed a clear boundary with no invasion into the adjacent tissue. The majority of tumor cells were round and medium-sized, with abundant pale cytoplasm, without obvious atypia and densely arranged in sheets. The tumor tissue was characterized by cartilage-like morphology and fibromyxoid and hyalinization matrix. Mitotic index was <1/10 high-power fields. Additionally, tumor cells were positive for S-100 and vimentin expression, but negative for smooth muscle actin, CD34, cytokeratin, desmin, human melanoma black 45 and melanoma A. Ki67 index was ~1%. The patient underwent surgery and the tumor was totally removed. No recurrence was observed at the final 6-year follow-up. Based on the aforementioned findings, the patient was diagnosed as typical OFMT. Slow growth and clear boundaries often suggest an indolent nature to this type of tumor. However, close follow-up should be performed due to its malignant potential.

Antiviral and anti-inflammatory activities of chemical constituents from twigs of Mosla chinensis Maxim.

Seven undescribed compounds, including three flavones (1-3), one phenylpropanoid (19), three monoaromatic hydrocarbons (27-29), were isolated from the twigs of Mosla chinensis Maxim together with twenty-eight known compounds. The structures were characterized by HRESIMS, 1D and 2D NMR, and ECD spectroscopic techniques. Compound 20 displayed the most significant activity against A/WSN/33/2009 (H1N1) virus (IC50 = 20.47 µM) compared to the positive control oseltamivir (IC50 = 6.85 µM). Further research on the anti-influenza mechanism showed that compound 20 could bind to H1N1 virus surface antigen HA1 and inhibit the early attachment stage of the virus. Furthermore, compounds 9, 22, 23, and 25 displayed moderate inhibitory effects on the NO expression in LPS inducing Raw 264.7 cells with IC50 values of 22.78, 20.47, 27.66, and 30.14 µM, respectively.

Coral-Inspired Terahertz-Infrared Bi-Stealth Electronic Skin.

The development of electronic skin with dual stealth functionality is crucial for enabling devices to operate effectively in dynamic electromagnetic environments, thereby facilitating intelligent electromagnetic protection for autonomous perception. However, achieving compatibility between terahertz (THz) and infrared (IR) stealth technologies remains largely unexplored due to their inherent contradictions. Herein, inspired by natural corals, a novel coral-like multi-scale composite foam (CMSF) was proposed that ingeniously reconciles these contradictions. The design capitalizes on the conductive network and heat insulation properties of the foam skeleton, the loss effects and low infrared emission of metal particles, and the infrared transparency of magneto-optical materials. This approach leads to the realization of a THz-IR bi-stealth electronic skin concept. The CMSF exhibits a maximum reflection loss of 84.8 dB in the terahertz band, while its infrared stealth capability ensures environmental adaptability under varying temperatures. Furthermore, the electronic skin exhibits exceptional sensitivity and reliability as a wearable device for perceiving environmental changes. This advanced material, combining multispectral stealth with sensing capabilities, holds immense potential for applications ranging from camouflage technology to smart wearables.

Using Pupil Diameter for Psychological Resilience Assessment in Medical Students Based on SVM and SHAP Model.

Effectively assessing psychological resilience for medical students is vital for identifying at-risk individuals and developing tailored interventions. At present, few studies have combined physiological indexes of the human body and machine learning for psychological resilience assessment. This study presents a novel approach that employs pupil diameter features and machine learning to predict psychological resilience risk objectively. Firstly, we designed a stimulus paradigm (via auditory and visual stimuli) and collected pupil diameter data from participants using eye-tracking technology. Secondly, the pupil data was preprocessed, including linear interpolation, blink detection, and subtractive baseline correction. Thirdly, statistical metrics were extracted and optimal feature subsets were obtained by Recursive Feature Elimination with Cross-Validation (RFECV). Subsequently, the classification models, including Logistic Regression (LR), Random Forest (RF), Support Vector Machine (SVM), and eXtreme Gradient Boosting (XGBoost), were trained. The experimental results show that the SVM model has the best performance, and its balance accuracy, recall, and AUC reach 0.906, 0.89, and 0.932, respectively. Finally, we leveraged the Shapley additive explanation (SHAP) model for interpretability analysis. It revealed auditory stimuli have a more significant effect than visual stimuli in psychological resilience assessment. These findings suggested that pupil diameter could be a vital metric for assessing psychological resilience.

Ultrashort echo time MRI detects significantly lower collagen but higher pore water in the tibial cortex of female patients with osteopenia and osteoporosis.

Ultrashort echo time (UTE) MRI can quantify the major proton pool densities in cortical bone, including total (TWPD), bound (BWPD), and pore water (PWPD) proton densities, as well as the macromolecular proton density (MMPD), associated with the collagen content, which is calculated using macromolecular fraction (MMF) from UTE magnetization transfer (UTE-MT) modeling. This study aimed to investigate the differences in water and collagen contents in tibial cortical bone, between female osteopenia (OPe) patients, osteoporosis (OPo) patients, and young participants (Young). Being postmenopausal and above 55 yr old were the inclusion criteria for OPe and OPo groups. The tibial shaft of 14 OPe (72.5 ± 6.8 yr old), 31 OPo (72.0 ± 6.4 yr old), and 31 young subjects (28.0 ± 6.1 yr old) were scanned using a knee coil on a clinical 3T scanner. Basic UTE, inversion recovery UTE, and UTE-MT sequences were performed. Investigated biomarkers were compared between groups using Kruskal-Wallis test. Spearman's correlation coefficients were calculated between the TH DXA T-score and UTE-MRI results. MMF, BWPD, and MMPD were significantly lower in OPo patients than in the young group, whereas T1, TWPD, and PWPD were significantly higher in OPo patients. The largest OPo/Young average percentage differences were found in MMF (41.9%), PWPD (103.5%), and MMPD (64.0%). PWPD was significantly higher (50.7%), while BWPD was significantly lower (16.4%) in OPe than the Young group on average. MMF was found to be significantly lower (27%) in OPo patients compared with OPe group. T1, MMF, TWPD, PWPD, and MMPD values significantly correlated with the TH DXA T-scores (provided by the patients and only available for OPe and OPo patients). DXA T-score showed the highest correlations with PWPD (R = 0.55) and MMF (R = 0.56) values. TWPD, PWPD, and MMF estimated using the UTE-MRI sequences were recommended to evaluate individuals with OPe and OPo.

Ultrashort echo time (UTE) is an MRI technique that can quantify the water and collagen content of cortical bone. Water in the bone can be found residing in pores (pore water) or bound to the bone matrix (bound water). We investigated the differences in water and collagen contents of tibial cortical bone between female osteopenia patients, osteoporosis patients, and young participants. Bound water and collagen contents were significantly lower in osteoporosis patients than in the young group, whereas total water and pore water contents were significantly higher in osteoporosis patients. Pore water was significantly higher, while bound water was significantly lower in osteopenia than in the Young group. Collagen content was found to be significantly lower in osteoporosis patients compared with the osteopenia group. The estimated water and collagen contents were significantly correlated with the TH bone densitometry measures in the patients.