Comparison of adaptive imaging receiver coil (AIR) and traditional coil for multiplexed sensitivity encoding diffusion weighted imaging of the liver.

OBJECTIVES: To compare the image quality and efficacy of the Adaptive imaging receiver (AIR)TM coil (GE Healthcare) and the traditional coil for multiplexed sensitivity encoding diffusion-weighted imaging (MUSE-DWI) in the detection of focal liver lesions (FLLs). METHODS: Two groups of MUSE-DWI were obtained. Image quality was qualitatively evaluated by three independent blinded radiologists on a 5-point scale, and quantitative parameters were calculated by measurements of the region of interest in the liver and FLLs. McNemar's test was used to compare the characteristics and detectability. RESULTS: Less image noise, sharper contours, milder susceptibility artifacts, and better liver lesion conspicuity were found by all radiologists in 60 livers with 140 FLLs with the AIR coil than with the traditional coil (reader average mean, 4.3-4.4 vs. 3.7-4.0, P < 0.001). The signal-to-noise ratio (SNR) of the liver was significantly higher with the AIR coil than with the traditional coil (right lobe: mean, 8.89 vs.7.76, P < 0.05; left lobe: mean, 7.14 vs.6.19, P < 0.001), and the SNR of FLLs (mean, 24.62 vs. 21.01, P < 0.001) and lesion-to-liver CNR (mean, 16.61 vs. 14.02, P < 0.001) exhibited significant differences between the AIR coil and the traditional coil. Besides, superior detection of FLLs was observed with the AIR coil compared to the traditional coil (95.7% [134/140] vs. 85.7% [120/140], P < 0.001). CONCLUSIONS: The AIR coil yields less noise, fewer distortions, better lesion detectability, higher SNR of the liver and FLLs, and improved lesion-to-liver CNR during liver MUSE-DWI. Thus, it is a feasible and effective scanning scheme in liver MRI. ADVANCES IN KNOWLEDGE: The AIR coil improves SNR and the quality of liver MR imaging compared with the traditional coil.

Zero echo time MRI improved detection of erosions and sclerosis in the sacroiliac joint in comparison with LAVA-flex.

Background: T1-weighted spoiled 3D Gradient Recalled Echo pulse sequences, exemplified by Liver Acquisition with Volume Acceleration-flexible MRI (LAVA-Flex), are currently the preferred MR sequence for detecting erosions of the sacroiliac joint (SIJ). However, zero echo time MRI (ZTE) is recently reported to provide excellent visualization of the cortical bone. Purpose: To directly compare the diagnostic accuracy of ZTE and LAVA-Flex in the detection of structural lesions of the SIJ, including erosions, sclerosis and joint space changes. Materials and methods: Two readers independently reviewed the ldCT, ZTE and LAVA-Flex images of 53 patients diagnosed as axSpA and scored the erosions, sclerosis and joint space changes. Sensitivity, specificity and Cohen's kappa (κ) of ZTE and LAVA-Flex were calculated, while McNemar's test was employed to compare the two sequences for the positivity of detecting the structural lesions. Results: Analysis of diagnostic accuracy showed a higher sensitivity of ZTE in comparison with LAVA-Flex in the depiction of erosions (92.5% vs 81.5%, p<0.001), especially first-degree erosions (p<0.001) and second-degree erosions (p<0.001), as well as sclerosis (90.6% vs 71.2%, p<0.001), but not joint space changes (95.2% vs 93.8%, p=0.332). Agreement with ldCT was also higher in ZTE in the detection of erosions than LAVA-Flex as indicated by the κ values (0.73 vs 0.47), as well as in the detection of sclerosis (0.92 vs 0.22). Conclusion: With ldCT as the reference standard, ZTE could improve diagnostic accuracy of erosions and sclerosis of the SIJ in patients suspected of axSpA, in comparison with LAVA-Flex.

Arterial spin labeling and diffusion-weighted MR imaging: quantitative assessment of renal pathological injury in chronic kidney disease.

PURPOSE: The aim of the study was to investigate the performance of arterial spin labeling (ASL), diffusion-weighted imaging (DWI), and clinical biomarkers in assessing renal pathological injury in CKD. MATERIALS AND METHODS: Forty-five biopsy-proven CKD patients and 17 healthy volunteers underwent DWI and ASL examinations. Renal cortical blood flow (RBF) and apparent diffusion coefficient (ADC) values were acquired. Correlations between RBF, ADC, serum creatinine (SCr), estimated glomerular filtration rate (eGFR), and pathological scores were assessed. The diagnostic efficacy of SCr, eGFR, RBF, and ADC in assessing renal pathological injury was assessed by ROC curve analysis. RESULTS: The cortical RBF, ADC, SCr, and eGFR were significantly correlated with the renal histology score (all p < 0.01). The AUC values of SCr, eGFR, RBF, and ADC were 0.705 (95% confidence interval (CI): 0.536-0.827), 0.718 (0.552-0.839), 0.823 (0.658-0.916), and 0.624 (0.451-0.786), respectively, in discriminating the minimal-mild renal pathological injury group (N = 30) from the control group (N = 17). The diagnostic ability of ASL was significantly higher than that of DWI (p = 0.049) and slightly but not significantly higher than that of eGFR and SCr (p = 0.151 and p = 0.129, respectively). When compared with that of eGFR, the sensitivity of ASL in detecting early renal injury increased from 50 to 70% (p = 0.014). However, in differentiating between the minimal-mild and moderate-severe renal injury groups (N = 15), there was no significant difference in diagnostic ability among the four parameters (all p > 0.05). CONCLUSION: ASL is practicable for noninvasive evaluation of renal pathology, especially for predicting early renal pathological injury in CKD patients.

Exosomes-Loaded Electroconductive Hydrogel Synergistically Promotes Tissue Repair after Spinal Cord Injury via Immunoregulation and Enhancement of Myelinated Axon Growth.

Electroconductive hydrogels are very attractive candidates for accelerated spinal cord injury (SCI) repair because they match the electrical and mechanical properties of neural tissue. However, electroconductive hydrogel implantation can potentially aggravate inflammation, and hinder its repair efficacy. Bone marrow stem cell-derived exosomes (BMSC-exosomes) have shown immunomodulatory and tissue regeneration effects, therefore, neural tissue-like electroconductive hydrogels loaded with BMSC-exosomes are developed for the synergistic treatment of SCI. These exosomes-loaded electroconductive hydrogels modulate microglial M2 polarization via the NF-κB pathway, and synergistically enhance neuronal and oligodendrocyte differentiation of neural stem cells (NSCs) while inhibiting astrocyte differentiation, and also increase axon outgrowth via the PTEN/PI3K/AKT/mTOR pathway. Furthermore, exosomes combined electroconductive hydrogels significantly decrease the number of CD68-positive microglia, enhance local NSCs recruitment, and promote neuronal and axonal regeneration, resulting in significant functional recovery at the early stage in an SCI mouse model. Hence, the findings of this study demonstrate that the combination of electroconductive hydrogels and BMSC-exosomes is a promising therapeutic strategy for SCI repair.

Dose optimization of intrathecal administration of human umbilical cord mesenchymal stem cells for the treatment of subacute incomplete spinal cord injury.

Human umbilical cord mesenchymal stem cells (hUC-MSCs) are a promising candidate for spinal cord injury (SCI) repair owing to their advantages of low immunogenicity and easy accessibility over other MSC sources. However, modest clinical efficacy hampered the progression of these cells to clinical translation. This discrepancy may be due to many variables, such as cell source, timing of implantation, route of administration, and relevant efficacious cell dose, which are critical factors that affect the efficacy of treatment of patients with SCI. Previously, we have evaluated the safety and efficacy of 4 × 106 hUC-MSCs/kg in the treatment of subacute SCI by intrathecal implantation in rat models. To search for a more accurate dose range for clinical translation, we compared the effects of three different doses of hUC-MSCs - low (0.25 × 106 cells/kg), medium (1 × 106 cells/kg) and high (4 × 106 cells/kg) - on subacute SCI repair through an elaborate combination of behavioral analyses, anatomical analyses, magnetic resonance imaging-diffusion tensor imaging (MRI-DTI), biotinylated dextran amine (BDA) tracing, electrophysiology, and quantification of mRNA levels of ion channels and neurotransmitter receptors. Our study demonstrated that the medium dose, but not the low dose, is as efficient as the high dose in producing the desired therapeutic outcomes. Furthermore, partial restoration of the γ-aminobutyric acid type A (GABAA) receptor expression by the effective doses indicates that GABAA receptors are possible candidates for therapeutic targeting of dormant relay pathways in injured spinal cord. Overall, this study revealed that intrathecal implantation of 1 × 106 hUC-MSCs/kg is an alternative approach for treating subacute SCI.

An injectable, self-healing, electroconductive extracellular matrix-based hydrogel for enhancing tissue repair after traumatic spinal cord injury.

Injectable biomaterial-based treatment is a promising strategy to enhance tissue repair after traumatic spinal cord injury (SCI) by bridging cavity spaces. However, there are limited reports of injectable, electroconductive hydrogels with self-healing properties being employed for the treatment of traumatic SCI. Hence, a natural extracellular matrix (ECM) biopolymer (chondroitin sulphate and gelatin)-based hydrogel containing polypyrrole, which imparted electroconductive properties, is developed for traumatic SCI repair. The resulting hydrogels showed mechanical (~928 Pa) and conductive properties (4.49 mS/cm) similar to natural spinal cord tissues. Moreover, the hydrogels exhibited shear-thinning and self-healing abilities, which allows it to be effectively injected into the injury site and to fill the lesion cavity to accelerate the tissue repair of traumatic SCI. In vitro, electroconductive ECM hydrogels promoted neuronal differentiation, enhanced axon outgrowth, and inhibited astrocyte differentiation. The electroconductive ECM hydrogel activated endogenous neural stem cell neurogenesis in vivo (n = 6), and induced myelinated axon regeneration into the lesion site via activation of the PI3K/AKT and MEK/ERK pathways, thereby achieving significant locomotor function restoration in rats with spinal cord injury (p < 0.001, compared to SCI group). Overall, the injectable self-healing electroconductive ECM-based hydrogels developed in this study are ideal biomaterials for treatment of traumatic SCI.

Quantification of lumbar vertebral fat deposition: Correlation with menopausal status, non-alcoholic fatty liver disease and subcutaneous adipose tissue.

Purpose: To assess abdominal fat deposition and lumbar vertebra with iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL-IQ) and investigate their correlation with menopausal status. Materials and Methods: Two hundred forty women who underwent routine abdominal MRI and IDEAL-IQ between January 2016 and April 2021 were divided into two cohorts (first cohort: 120 pre- or postmenopausal women with severe fatty livers or without fatty livers; second cohort: 120 pre- or postmenopausal women who were obese or normal weight). The fat fraction (FF) values of the liver (FFliver) and lumbar vertebra (FFlumbar) in the first group and the FF values of subcutaneous adipose tissue (SAT) (FFSAT) and FFlumbar in the second group were measured and compared using IDEAL-IQ. Results: Two hundred forty women were evaluated. FFlumbar was significantly higher in both pre- and postmenopausal women with severe fatty liver than in patients without fatty livers (premenopausal women: p < 0.001, postmenopausal women: p < 0.001). No significant difference in the FFlumbar was observed between obese patients and normal-weight patients among pre- and postmenopausal women (premenopausal women: p = 0.113, postmenopausal women: p = 0.092). Significantly greater lumbar fat deposition was observed in postmenopausal women than in premenopausal women with or without fatty liver and obesity (p < 0.001 for each group). A high correlation was detected between FFliver and FFlumbar in women with severe fatty liver (premenopausal women: r=0.76, p<0.01; postmenopausal women: r=0.82, p<0.01). Conclusion: Fat deposition in the vertebral marrow was significantly associated with liver fat deposition in postmenopausal women.

Extracellular Matrix-Based Conductive Interpenetrating Network Hydrogels with Enhanced Neurovascular Regeneration Properties for Diabetic Wounds Repair.

The critical effects that impair diabetic wound healing are characterized by poor vascularization and severe peripheral neuropathy. Current management strategies for diabetic wound healing are unsatisfactory, due to the paucity of neurovascular regeneration at the wound site. Importantly, conductivity in skin tissue is reported to be essential for modulating myriad biological processes especially vascular and nerve regeneration. Herein, an extracellular matrix (ECM)-based conductive dressing is synthesized from an interpenetrating polymer network hydrogel composed of gelatin methacryloyl, oxidized chondroitin sulfate (OCS), and OCS-polypyrrole conductive nanoparticles that can promote diabetic wound repairing by enhancing local neurovascular regeneration. The conductive hydrogels combine the advantageous features of water-swollen hydrogels with conductive polymers (CPs) to provide tissue-matching electrical conductivity and mechanical properties for neurovascular regeneration. In vitro and in vivo studies show that the conductive hydrogel can promote neurovascular regeneration by increasing intracellular Ca2+ concentration, which subsequently promotes phosphorylation of proteins in the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) and mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) pathways. Furthermore, the conductive hydrogel stimulates full-thickness diabetic wound repair on day 14 by promoting local neurovascular regeneration and collagen deposition. These findings corroborate that the ECM-based conductive interpenetrating network hydrogel dressing significantly promotes wound repairing due to its neurovascular regeneration properties, suggesting that they are suitable candidates for diabetic wound repair.

Development and Validation of a Deep Learning Algorithm to Automatic Detection of Pituitary Microadenoma From MRI.

Background: It is often difficult to diagnose pituitary microadenoma (PM) by MRI alone, due to its relatively small size, variable anatomical structure, complex clinical symptoms, and signs among individuals. We develop and validate a deep learning -based system to diagnose PM from MRI. Methods: A total of 11,935 infertility participants were initially recruited for this project. After applying the exclusion criteria, 1,520 participants (556 PM patients and 964 controls subjects) were included for further stratified into 3 non-overlapping cohorts. The data used for the training set were derived from a retrospective study, and in the validation dataset, prospective temporal and geographical validation set were adopted. A total of 780 participants were used for training, 195 participants for testing, and 545 participants were used to validate the diagnosis performance. The PM-computer-aided diagnosis (PM-CAD) system consists of two parts: pituitary region detection and PM diagnosis. The diagnosis performance of the PM-CAD system was measured using the receiver operating characteristics (ROC) curve and area under the ROC curve (AUC), calibration curve, accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and F1-score. Results: Pituitary microadenoma-computer-aided diagnosis system showed 94.36% diagnostic accuracy and 98.13% AUC score in the testing dataset. We confirm the robustness and generalization of our PM-CAD system, the diagnostic accuracy in the internal dataset was 96.50% and in the external dataset was 92.26 and 92.36%, the AUC was 95.5, 94.7, and 93.7%, respectively. In human-computer competition, the diagnosis performance of our PM-CAD system was comparable to radiologists with >10 years of professional expertise (diagnosis accuracy of 94.0% vs. 95.0%, AUC of 95.6% vs. 95.0%). For the misdiagnosis cases from radiologists, our system showed a 100% accurate diagnosis. A browser-based software was designed to assist the PM diagnosis. Conclusions: This is the first report showing that the PM-CAD system is a viable tool for detecting PM. Our results suggest that the PM-CAD system is applicable to radiology departments, especially in primary health care institutions.

Bone mesenchymal stem cell-derived exosome-loaded injectable hydrogel for minimally invasive treatment of spinal cord injury.

Aim: Bone mesenchymal stem cell-derived exosomes (Exos) have been shown to exert therapeutic effects in spinal cord injury (SCI). In this study, we aimed to apply bioengineering approaches to promote Exo retention and their sustained release for SCI repair. Materials & methods: 3D gelatin methacrylate hydrogel (GelMA) was used as a transplanted Exo delivery system (GelMA-Exos). The viability, proliferation, and differentiation of neural stem cells cultured on hydrogel were assessed. Further, GelMA-Exos was injected into the damaged lesions to assess its repair potential. Results: GelMA hydrogel enhanced the retention of Exos, which promoted the neuronal differentiation and extension in vitro. Furthermore, GelMA-Exos promoted neurogenesis and attenuated glial scars in the damaged lesions. Conclusion: The injectable Exo-loaded 3D hydrogel induced neurological functional recovery post SCI.

Self-curling electroconductive nerve dressing for enhancing peripheral nerve regeneration in diabetic rats.

Conductive scaffolds have been shown to exert a therapeutic effect on patients suffering from peripheral nerve injuries (PNIs). However, conventional conductive conduits are made of rigid structures and have limited applications for impaired diabetic patients due to their mechanical mismatch with neural tissues and poor plasticity. We propose the development of biocompatible electroconductive hydrogels (ECHs) that are identical to a surgical dressing in this study. Based on excellent adhesive and self-healing properties, the thin film-like dressing can be easily attached to the injured nerve fibers, automatically warps a tubular structure without requiring any invasive techniques. The ECH offers an intimate and stable electrical bridge coupling with the electrogenic nerve tissues. The in vitro experiments indicated that the ECH promoted the migration and adhesion of the Schwann cells. Furthermore, the ECH facilitated axonal regeneration and remyelination in vitro and in vivo through the MEK/ERK pathway, thus preventing muscle denervation atrophy while retaining functional recovery. The results of this study are likely to facilitate the development of non-invasive treatment techniques for PNIs in diabetic patients utilizing electroconductive hydrogels.

Quantification of penile fat infiltration using the mDIXON Quant sequence: a pilot study on the correlation with penis hardness and erectile dysfunction.

OBJECTIVE: The purpose of this study was to determine fat/water signal ratios using the mDIXON Quant sequence, quantitatively assess fat infiltration in the penis, and explore its possible relationship with penile hardness and erectile dysfunction. METHODS: Routine pelvic MRI with the mDIXON Quant sequence was performed in 62 subjects, including 22 people in the normal group, 20 people in the normal erectile hardness group, and 20 people in the erectile dysfunction (ED) group. The fat/water signal ratio in the penis was measured using the mDIXON Quant sequence. Shear wave elastography was used to evaluate the hardness of the corpus cavernosa of the penis. RESULTS: The fat/water signal ratio of the corpus spongiosum was significantly lower than that of the corpus cavernosa in the normal group (p = 0.03) and ED group (p < 0.01). There was no significant difference in the fat/water signal ratios between the normal group and the normal erectile hardness group. Fat infiltration was significantly lower, and erectile hardness was significantly higher in the normal erectile hardness group than in the ED group, and the fat infiltration in the left and right corpus cavernosa was inversely proportional to the erectile hardness of the penis. CONCLUSION: This study suggests that mDIXON Quant can be used as a non-invasive, quantitative, and objective method for evaluating penile fat infiltration. This method could help diagnose penile fat infiltration in patients with erectile dysfunction and varying body mass indexes. Our results could also allow for a more accurate diagnosis and monitoring of erectile hardness function by quantitatively measuring penile fat infiltration. ADVANCES IN KNOWLEDGE: (1) The proton density fat fraction technology is a new tool for the objective, quantitative and non-invasive evaluation of penile fat infiltration. (2) The quantitative measurement of fat infiltration in the corpora cavernosa might help diagnose and monitor penile erection hardness and its function more accurately.

Exosome-functionalized polyetheretherketone-based implant with immunomodulatory property for enhancing osseointegration.

The host immune response effecting on biomaterials is critical to determine implant fates and bone regeneration property. Bone marrow stem cells (BMSCs) derived exosomes (Exos) contain multiple biosignal molecules and have been demonstrated to exhibit immunomodulatory functions. Herein, we develop a BMSC-derived Exos-functionalized implant to accelerate bone integration by immunoregulation. BMSC-derived Exos were reversibly incorporated on tannic acid (TA) modified sulfonated polyetheretherketone (SPEEK) via the strong interaction of TA with biomacromolecules. The slowly released Exos from SPEEK can be phagocytosed by co-cultured cells, which could efficiently improve the biocompatibilities of SPEEK. In vitro results showed the Exos loaded SPEEK promoted macrophage M2 polarization via the NF-κB pathway to enhance BMSCs osteogenic differentiation. Further in vivo rat air-pouch model and rat femoral drilling model assessment of Exos loaded SPEEK revealed efficient macrophage M2 polarization, desirable new bone formation, and satisfactory osseointegration. Thus, BMSC-derived Exos-functionalized implant exerted osteoimmunomodulation effect to promote osteogenesis.

Short-Term Effect of Lumbar Traction on Intervertebral Discs in Patients with Low Back Pain: Correlation between the T2 Value and ODI/VAS Score.

OBJECTIVE: The effect of lumbar traction on low back pain (LBP) patients is controversial. Our study aims to assess changes in the intervertebral disc water content after lumbar traction using T2 mapping and explore the correlation between changes in the T2 value and Oswestry Disability Index (ODI)/visual analogue scale (VAS) score. DESIGN: Lumbar spine magnetic resonance imaging was performed, and the ODI/VAS scores were recorded in all 48 patients. Midsagittal T2-weighted imaging and T2 mapping were performed to determine the Pfirrmann grade and T2 value. Then, the T2 values were compared between pre- and posttraction, and the correlation between changes in the T2 value and ODI/VAS scores were examined. RESULTS: In the traction group, the changes in the nucleus pulposus (NP) T2 values for Pfirrmann grades II-IV and the annulus fibrosus (AF) T2 values for Pfirrmann grade II were statistically significant after traction (P < 0.05). Changes in the mean NP T2 value of 5 discs in each patient and in the ODI/VAS score showed a strong correlation (r = 0.822, r = 0.793). CONCLUSION: T2 mapping can be used to evaluate changes in the intervertebral disc water content. Ten sessions of traction resulted in a significant increase in quantitative T2 measurements of the NP in discs for Pfirrmann grade II-IV degeneration and remission of the patients' clinical symptoms in the following 6 months. Changes in the mean NP T2 value of 5 discs in each patient were strongly correlated with changes in the ODI/VAS score.

Quantification of Fat Metaplasia in the Sacroiliac Joints of Patients With Axial Spondyloarthritis by Chemical Shift-Encoded MRI: A Diagnostic Trial.

Objective: To study the diagnostic performance of chemical shift-encoded MRI (CSE-MRI) in the diagnosis of axial spondyloarthritis (axSpA). Methods: CSE-MRI images were acquired for consecutive patients complaining of back pain as well as healthy volunteers. Proton density fat fraction (PDFF) values were measured independently by two readers. Diagnostic performance of CSE-MRI was analyzed by sensitivity analysis and ROC curve analysis. Logistic regression analysis was employed to investigate the risk factors of extensive fat deposition in the SIJs. Results: A total of 52 r-axSpA patients, 37 nr-axSpA patients, 24 non-SpA patients and 34 healthy volunteers were included. Mean PDFF values in the SIJs of patients with r-axSpA and nr-axSpA (72.7% and 64.5%) were significantly higher than non-SpA patients and healthy volunteers (56.0% and 57.6%) (p<0.001). By defining extensive fat deposition in the SIJs as ≥8 ROIs with PDFF values over 70%, its sensitivity and specificity in diagnosing axSpA reached 72.47% and 86.21%%. By joining bone marrow edema (BME) with ≥8 ROIs (PDFF>70%), 22 (24.71%) and 23 (25.84%) more axSpA patients were classified as SIJ MRI (+) by reader 1 and 2, but specificities decreased by 15.52% and 10.34%. Multivariate logistic regression analysis confirmed longer disease duration as the independent risk factor of extensive fat deposition in SIJs (OR=1.15, 95%CI[1.03, 1.32]), while bDMARDs medication was a protective factor (OR=0.15, 95%CI[0.04, 0.51]). Conclusion: CSE-MRI is a reliable tool to quantitively assess the fat metaplasia in the SIJs of axSpA patients. Extensive fat deposition in the SIJs could add incremental diagnostic value to BME, but at the cost of decreased specificities.

Subarachnoid transplantation of human umbilical cord mesenchymal stem cell in rodent model with subacute incomplete spinal cord injury: Preclinical safety and efficacy study.

Functional multipotency renders human umbilical cord mesenchymal stem cell (hUC-MSC) a promising candidate for the treatment of spinal cord injury (SCI). However, its safety and efficacy have not been fully understood for clinical translation. In this study, we performed cellular, kinematic, physiological, and anatomical analyses, either in vitro or in vivo, to comprehensively evaluate the safety and efficacy associated with subarachnoid transplantation of hUC-MSCs in rats with subacute incomplete SCI. Concerning safety, hUC-MSCs were shown to have normal morphology, excellent viability, steady proliferation, typical biomarkers, stable karyotype in vitro, and no tumorigenicity both in vitro and in vivo. Following subarachnoid transplantation of hUC-MSCs in the subject rodents, the biodistribution of hUC-MSCs was restricted to the spinal cord, and no toxicity to immune system or organ function was observed. Body weight, organ weight, and the ratio of the latter upon the former between stem cell-transplanted rats and placebo-injected rats revealed no statistical differences. Regarding efficacy, hUC-MSCs could differentiate into osteoblasts, chondrocytes, adipocytes and neural progenitor cells in vitro. While in vivo studies revealed that subarachnoid transplantation of stem cells resulted in significant improvement in locomotion, earlier automatic micturition recovery and reduced lesion size, which correlated with increased regeneration of tracking fiber and reduced parenchymal inflammation. In vivo luminescence imaging showed that a few of the transplanted luciferase-labeled hUC-MSCs tended to migrate towards the lesion epicenter. Shortened latency and enhanced amplitude were also observed in both motor and sensory evoked potentials, indicating improved signal conduction in the damaged site. Immunofluorescent staining confirmed that a few of the administrated hUC-MSCs integrated into the spinal cord parenchyma and differentiated into astrocytes and oligodendrocytes, but not neurons. Moreover, decreased astrogliosis, increased remyelination, and neuron regeneration could be observed. To the best of our knowledge, this preclinical study provides detailed safety and efficacy evidence regarding intrathecal transplantation of hUC-MSCs in treating SCI for the first time and thus, supports its initiation in the following clinical trial.

Quantification of fat deposition in the testis and epididymis using mDIXON Quant sequence: correlation with age and ejaculation.

PURPOSE: The objective of this study was to quantitatively assess fat deposition in the testis and epididymis by measuring the fat/water signal ratios with mDIXON Quant and to investigate its correlation with age and ejaculation. MATERIALS AND METHODS: Routine pelvic magnetic resonance imaging and mDIXON Quant were performed on 120 subjects. The fat/water signal ratios of the testis and epididymis were measured based on the fat/water signal intensity on mDIXON Quant. RESULTS: The fat/water signal ratio values of the testis and epididymis in the early adulthood group (0.952-3.550%, p < 0.05, and 5.182-12.725%, p < 0.05, respectively) were significantly higher than those in the late childhood group (0.611-2.198% and 1.310-4.520%) and in the youth group (0.659-2.360% and 1.568-4.469%), and they were lower than those in the middle adulthood group (1.538-4.249%, p < 0.05, and 5.830-19.002%, p < 0.05). The fat deposition decreased in the testis of the youth group, who ejaculated more than ten times per month (0.750-2.022%, p < 0.05), and the fat/water signal ratios of the epididymis decreased in one subject in the early adulthood group who had three ejaculations within 12 h. CONCLUSION: The findings of this study suggest that mDIXON Quant may be useful as a noninvasive, quantitative, and objective method for evaluating the fat deposition of the testis and epididymis. This method can provide guidance for fat deposition in the testis and epididymis in different age groups with varying ejaculation experiences. Additionally, our findings may facilitate more accurate diagnosis and monitoring of the reproductive function of the testis and epididymis by quantitatively measuring their fat deposition with age.