High-resolution Magnetic Resonance Research Articles

Morphology of the anterior mesorectum: a new predictor for local recurrence in patients with rectal cancer.

Pre-operative assessment with high-resolution magnetic resonance imaging (MRI) is useful for assessing the risk of local recurrence (LR) and survival in rectal cancer. However, no studies have explored the clinical importance of the morphology of the anterior mesorectum, especially in patients with anterior cancer. Hence, the study aimed to investigate the impact of the morphology of the anterior mesorectum on LR in patients with primary rectal cancer. A retrospective study was performed on 176 patients who underwent neoadjuvant treatment and curative-intent surgery. Patients were divided into two groups according to the morphology of the anterior mesorectum on sagittal MRI: (1) linear type: the anterior mesorectum was thin and linear; and (2) triangular type: the anterior mesorectum was thick and had a unique triangular shape. Clinicopathological and LR data were compared between patients with linear type anterior mesorectal morphology and patients with triangular type anterior mesorectal morphology. Morphometric analysis showed that 90 (51.1%) patients had linear type anterior mesorectal morphology, while 86 (48.9%) had triangular type anterior mesorectal morphology. Compared to triangular type anterior mesorectal morphology, linear type anterior mesorectal morphology was more common in females and was associated with a higher risk of circumferential resection margin involvement measured by MRI (35.6% vs. 16.3%, P = 0.004) and a higher 5-year LR rate (12.2% vs. 3.5%, P = 0.030). In addition, the combination of linear type anterior mesorectal morphology and anterior tumors was confirmed as an independent risk factor for LR (odds ratio = 4.283, P = 0.014). The classification established in this study was a simple way to describe morphological characteristics of the anterior mesorectum. The combination of linear type anterior mesorectal morphology and anterior tumors was an independent risk factor for LR and may act as a tool to assist with LR risk stratification and treatment selection.

Segmentation of Vestibular Schwannomas on Postoperative Gadolinium-Enhanced T1-Weighted and Noncontrast T2-Weighted Magnetic Resonance Imaging Using Deep Learning.

Surveillance of postoperative vestibular schwannomas currently relies on manual segmentation and measurement of the tumor by content experts, which is both labor intensive and time consuming. We aimed to develop and validate deep learning models for automatic segmentation of postoperative vestibular schwannomas on gadolinium-enhanced T1-weighted magnetic resonance imaging (GdT1WI) and noncontrast high-resolution T2-weighted magnetic resonance imaging (HRT2WI). A supervised machine learning approach using a U-Net model was applied to segment magnetic resonance imaging images into pixels representing vestibular schwannoma and background pixels. Tertiary care hospital. Our retrospective data set consisted of 122 GdT1WI and 122 HRT2WI studies in 82 postoperative adult patients with a vestibular schwannoma treated with subtotal surgical resection between September 1, 2007, and April 17, 2018. Forty-nine percent of our cohort was female, the mean age at the time of surgery was 49.8 years, and the median time from surgery to follow-up scan was 2.26 years. N/A. Tumor areas were manually segmented in axial images and used as ground truth for training and evaluation of the model. We measured the Dice score of the predicted segmentation results in comparison to manual segmentations from experts to assess the model's accuracy. The GdT1WI model achieved a Dice score of 0.89, and the HRT2WI model achieved a Dice score of 0.85. We demonstrated that postoperative vestibular schwannomas can be accurately segmented on GdT1WI and HRT2WI without human intervention using deep learning. This artificial intelligence technology has the potential to improve the postoperative surveillance and management of patients with vestibular schwannomas.

Extra-articular findings in patients with suspected labral tear and value of screening pelvis sequence

Objectives: There are multiple etiologies of hip pain, of which labral tear is one of the most common in young adults which may be difficult to distinguish on history and clinical examination. Labral tears can be diagnosed using high-resolution non-contrast magnetic resonance imaging (MRI) or MR arthrogram that involves imaging the concerned hip. At our institute, we perform an additional proton density fat saturated axial sequence of the pelvis to screen for alternative pathology and we investigate the value of this in this study. Material and Methods: A retrospective review of high-resolution non-arthrographic 3T MR of hips that were referred from young adult hip services with a history of hip or groin pain and the clinical suspicion of a labral tear over 2 years was performed. Those <50 years were included in the study. Results: Of 648 patients with suspected labral tears, 18% showed evidence of extra-articular hip pathologies (sacroiliac joint pathology, iliopsoas pathology, and ischiofemoral impingement) on MRI. This study has shown that approximately one in five patients with a clinically suspected labral tear showed radiological evidence of extra-articular hip pathology (sacroiliac joint pathology, iliopsoas pathology, ischiofemoral impingement, and hamstring pathology). There is therefore the potential for misdiagnosis and increased morbidity if these alternative diagnoses were not appreciated. Conclusion: A high-resolution hip MRI protocol for suspected labral tears of the hip joint should include at least one sequence of the entire pelvis to evaluate for extra-articular findings.

Brain morphometric abnormalities and their associations with affective symptoms in males with methamphetamine use disorder during abstinence.

BackgroundMethamphetamine (METH) use induces neurotoxic effects in brain structures and affective symptoms that persist during abstinence. However, the brain morphometry of individuals with METH use disorder (MUD) remains unclear, as well as their associations with affective symptoms during abstinence.MethodsForty-eight abstinent males with MUD and 66 age-, sex-, and education-matched healthy controls (HCs) underwent high-resolution T1-weighted magnetic resonance imaging. Cortical thickness, surface area, volume, local gyrification index (LGI), and subcortical volume were obtained with FreeSurfer software. Brain morphometry differences between groups and their associations with affective symptoms and drug abuse history within the males with MUD were examined, with intracranial volume, age, and years of education as covariates.ResultsCompared with the HCs, the individuals with MUD showed a significantly higher LGI in the right cuneus gyrus, left lingual gyrus, bilateral supramarginal gyrus, right inferior parietal gyrus (IPG), and right dorsal anterior cingulate cortex (clusterwise p < 0.05, Monte Carlo-corrected), as well as a smaller volume of the left nucleus accumbens (NAcc) (p < 0.05, FDR-corrected). However, there were no significant group differences in cortical thickness, area or volume. In addition, the LGI in the right IPG was positively associatedwith the severity of depression and anxiety symptoms in MUDs (p < 0.05, FDR-corrected).ConclusionBrain morphometric abnormalities in abstinent males with MUD were characterized by hypergyrification across multiple mid-posterior brain regions anda smaller volume of the left NAcc.Gyrification of the right IPG may be a potential neural substrate underlying the affective symptoms experienced by MUDs during abstinence.

Enhanced Visualisation of Normal Anatomy with Potential Use of Augmented Reality Superimposed on Three-Dimensional Printed Models.

Anatomical knowledge underpins the practice of many healthcare professions. While cadaveric specimens are generally used to demonstrate realistic anatomy, high cost, ethical considerations and limited accessibility can often impede their suitability for use as teaching tools. This study aimed to develop an alternative to traditional teaching methods; a novel teaching tool using augmented reality (AR) and three-dimensional (3D) printed models to accurately demonstrate normal ankle and foot anatomy. An open-source software (3D Slicer) was used to segment a high-resolution magnetic resonance imaging (MRI) dataset of a healthy volunteer ankle and produce virtual bone and musculature objects. Bone and musculature were segmented using seed-planting and interpolation functions, respectively. Virtual models were imported into Unity 3D, which was used to develop user interface and achieve interactability prior to export to the Microsoft HoloLens 2. Three life-size models of bony anatomy were printed in yellow polylactic acid and thermoplastic polyurethane, with another model printed in white Visijet SL Flex with a supporting base attached to its plantar aspect. Interactive user interface with functional toggle switches was developed. Object recognition did not function as intended, with adequate tracking and AR superimposition not achieved. The models accurately demonstrate bony foot and ankle anatomy in relation to the associated musculature. Although segmentation outcomes were sufficient, the process was highly time consuming, with effective object recognition tools relatively inaccessible. This may limit the reproducibility of augmented reality learning tools on a larger scale. Research is required to determine the extent to which this tool accurately demonstrates anatomy and ascertain whether use of this tool improves learning outcomes and is effective for teaching anatomy.

Lesion probability map in cerebral vein thrombosis due to Behçet's disease.

Behçet's disease (BD) is a multisystemic inflammatory disease. Cerebral venous sinus thrombosis (CVST) is the second most common form of neuro-BD after parenchymal central nervous system involvement. The purpose of this study was to construct flow-void probability maps of patients with CVST with and without BD to visually illustrate the impacted cerebral venous sinuses, to compare the subgroups of patients, and investigate the effect of thrombus localization on clinical findings. Seventeen patients with a diagnosis of BD-related CVST (CVST-BD) and 23 patients with a diagnosis of CVST related to other etiologies (CVST-O) were included. We collected data including gender, age at onset of BD and CVST, presenting symptoms, neurological findings, and the etiology. High-resolution magnetic resonance venographies obtained during CVST were used to mark and digitalize thrombosed areas. Thrombus probability and subtraction maps were created to reveal the differences between the subgroups. Remarkably, all patients with CVST-BD had thrombosis in the transverse sinus (TS). However, TS was affected in 73.9% of the CVST-O patients (17/17 in CVST-BD vs 17/23 in CVST-O, P=.03). Thrombosis developed mostly in the superior sagittal sinus (SSS) and TS in the CVST-O group (11/23, 47.8% and 17/23, 73.9%, respectively). The frequency of SSS thrombosis tended to be higher in the CVST-O (47.8% vs 23.5%, P=.19). Venous infarction and hemorrhage were less common in patients with CVST-BD. The only clinical symptom in most of the CSVT patients with BD was headache due to elevated intracranial pressure. TS thrombosis was more common in patients with BD.

Abnormal cortical morphology in children and adolescents with intermittent exotropia.

PurposeTo investigate cortical differences, age-related cortical differences, and structural covariance differences between children with intermittent exotropia (IXT) and healthy controls (HCs) using high-resolution magnetic resonance imaging (MRI).MethodsSixteen IXT patients and 16 HCs underwent MRI using a 3-T MR scanner. FreeSurfer software was used to obtain measures of cortical volume, thickness, and surface area. Group differences in cortical thickness, volume and surface area were examined using a general linear model with intracranial volume (ICV), age and sex as covariates. Then, the age-related cortical differences between the two groups and structural covariance in abnormal morphometric changes were examined.ResultsCompared to HCs, IXT patients demonstrated significantly decreased surface area in the left primary visual cortex (PVC), and increased surface area in the left inferior temporal cortex (ITC). We also found increased cortical thickness in the left orbitofrontal cortex (OFC), right middle temporal cortex (MT), and right inferior frontal cortex (IFC). No significant differences were found in cortical volume between the two groups. There were several negative correlations between neuroanatomic measurements and age in the HC group that were not observed in the IXT group. In addition, we identified altered patterns of structural correlations across brain regions in patients with IXT.ConclusionTo our knowledge, this study is the first to characterize the cortical morphometry of the children and adolescents with IXT. Based on our results, children and adolescents with IXT exhibited significant alterations in the PVC and association cortices, different cortical morphometric development patterns, and disrupted structural covariance across brain regions.

The value of high-resolution imaging in an occult peroneal intraneural ganglion cyst: illustrative case.

BACKGROUNDFoot drop is a common complaint with a broad differential diagnosis making imaging a key part of the diagnostic workup. The authors present a patient with an occult peroneal intraneural ganglion cyst who underwent imaging with high-frequency ultrasound (US) and high-resolution magnetic resonance imaging (MRI) to highlight the role of such techniques in cases of peroneal neuropathy.OBSERVATIONSIntraneural ganglion cysts are emerging as a common cause of common peroneal neuropathy. Imaging with US and MRI is a valuable tool used to illustrate the pertinent anatomy and identify the articular branch joint connection and cyst as part of the surgical planning and definitive management.LESSONSIntraneural ganglion cysts can be small or nearly invisible and failure to appreciate the intraneural cyst can lead to symptom or cyst persistence or recurrence. High-resolution modalities can be useful in the diagnosis and surgical planning of difficult cases.

Cerebral hemodynamics during atrial fibrillation: computational fluid dynamics (CFD) analysis of lenticulostriate arteries using 7T high-resolution magnetic resonance imaging

Abstract Background Lenticulostriate arteries (LSAs) are small perforating arteries (0.1–1 mm diameter), perpendicularly departing from middle cerebral artery (MCA) and supplying blood flow to important cerebral subcortical and basal ganglia areas. LSAs are involved in silent strokes and cerebral small vessel disease, potentially leading to cognitive decline and vascular dementia. There is growing evidence that atrial fibrillation (AF), the most common cardiac arrhythmia, increases the risk of dementia even in the absence of clinical strokes. AF also increase the risk of small vessel disease. AF may alter deep cerebral hemodynamics per se, however no data exists regarding a possible impact of AF on MCA-LSA branching sites hemodynamics. Purpose To use computational fluid dynamics (CFD) analysis to study the hemodynamics of LSAs-MCA branching sites. Methods 7T high-resolution magnetic resonance imaging (HR-MRI) brain scans (Figure 1, panel a) were used to derive detailed geometrical models of LSAs-MCA branching sites. CFD analysis was then conducted, simulating AF conditions as well as sinus rhythm (SR), at different ventricular rates (from 50 to 130 bpm). Results Geometrical models were retrieved from HR-MRI scans of 7 patients. By means of the most significant metrics, such as wall shear stress (WSS; Figure 1, panel b), wall shear stress gradient (WSSG), and flow velocity (FV), a comparison between SR and AF was performed. Conclusion CFD analysis of LSAs-MCA branching sites using geometrical models derived from HR-MRI brain scans was feasible and allows to quantify the impact of AF on these critical ramifications of the MCA. Funding Acknowledgement Type of funding sources: None.

S167 Comparison of High-Resolution Anorectal Manometry and Magnetic Resonance Defecography in Patients With Obstructive Defecation: Are Both Tests Necessary?

Introduction: Investigation of evacuation disorders is often pursued in patients with symptoms of obstructive defecation. High-resolution anorectal manometry (HR-ARM) is a simple, safe and widely available test to diagnose pelvic floor dysfunction. A more costly and less accessible test is magnetic resonance defecography (MRD). This study aims to qualify the added value of MRD in diagnosing pelvic floor disorders. Methods: HR-ARM and MRD performed in patients with a diagnosis of constipation between 1/1/2020 and 5/15/22 at Mayo Clinic were identified using Epic SlicerDicer. Univariate and multivariate analyses were used to compare findings on MRD in patients with and without abnormal HR-ARM. Results: Seventy-six consecutive patients (81.8% female, 94.8% white, age 19-82) who underwent both HR-ARM and MRD were included. The majority had evidence of dyssynergia on HR-ARM (n=49, 64.5%). Patients with dyssynergia on HR-ARM were significantly more likely to have prolonged balloon expulsion at both >60 and >30 seconds (p< 0.00001) and incomplete gel expulsion on MRD (p=0.00008) (Table). However, they were not more likely to have a clinically significant rectocele measuring >2cm (p=0.5093) or evidence of rectal prolapse (p=0.071). An increased number of vaginal deliveries was correlated with a higher likelihood of having a rectocele >2cm (r=0.24, p< 0.05). Conclusion: Anatomic findings on MRD were similar between patients with and without evidence of dyssynergia identified by HR-ARM. In this retrospective review, undergoing MRD in addition to HR-ARM does not appear to provide additional diagnostic information to guide therapeutic recommendations. Large prospective studies to evaluate the added value of MRD are needed. Table 1. - Findings on MRD and balloon expulsion test in patients with and without dyssynergia on HR-ARM Dyssynergia on HR-ARM No dyssynergia on HR-ARM P value n= 49 (64.5%) n = 27 (35.5%) Balloon Expulsion >60 sec 30 (61.2%) 0 (0.0%) p< 0.00001 Balloon Expulsion >30 sec 32 (65.3%) 2 (7.4%) p< 0.00001 < 50% gel expulsion on MR 26 (53.1%) 2 (7.4%) p=0.00008 Rectocele on MR 26 (53.1%) 22 (81.5%) p=0.0139 >2 cm Rectocele on MR 21 (42.9%) 16 (59.3%) p=0.5093 >3 cm Rectocele on MR 10 (20.4%) 9 (33.3%) p=0.2113 >4 cm Rectocele on MR 3 (6.1%) 3 (11.1%) p=0.4413 Rectal Prolapse 5 (10%) 7 (31.8%) p=0.071

Anatomically curated segmentation of human subcortical structures in high resolution magnetic resonance imaging: An open science approach.

Magnetic resonance imaging (MRI)-based brain segmentation has recently been revolutionized by deep learning methods. These methods use large numbers of annotated segmentations to train algorithms that have the potential to perform brain segmentations reliably and quickly. However, training data for these algorithms are frequently obtained from automated brain segmentation systems, which may contain inaccurate neuroanatomy. Thus, the neuroimaging community would benefit from an open source database of high quality, neuroanatomically curated and manually edited MRI brain images, as well as the publicly available tools and detailed procedures for generating these curated data. Manual segmentation approaches are regarded as the gold standard for brain segmentation and parcellation. These approaches underpin the construction of neuroanatomically accurate human brain atlases. In addition, neuroanatomically precise definitions of MRI-based regions of interest (ROIs) derived from manual brain segmentation are essential for accuracy in structural connectivity studies and in surgical planning for procedures such as deep brain stimulation. However, manual segmentation procedures are time and labor intensive, and not practical in studies utilizing very large datasets, large cohorts, or multimodal imaging. Automated segmentation methods were developed to overcome these issues, and provide high data throughput, increased reliability, and multimodal imaging capability. These methods utilize manually labeled brain atlases to automatically parcellate the brain into different ROIs, but do not have the anatomical accuracy of skilled manual segmentation approaches. In the present study, we developed a custom software module for manual editing of brain structures in the freely available 3D Slicer software platform that employs principles and tools based on pioneering work from the Center for Morphometric Analysis (CMA) at Massachusetts General Hospital. We used these novel 3D Slicer segmentation tools and techniques in conjunction with well-established neuroanatomical definitions of subcortical brain structures to manually segment 50 high resolution T1w MRI brains from the Human Connectome Project (HCP) Young Adult database. The structural definitions used herein are associated with specific neuroanatomical ontologies to systematically interrelate histological and MRI-based morphometric definitions. The resulting brain datasets are publicly available and will provide the basis for a larger database of anatomically curated brains as an open science resource.

Fibromuscular dysplasia of internal carotid arteries: features on high-resolution magnetic resonance imaging

Fibromuscular dysplasia (FMD) is a noninflammatory and nonatherosclerotic disease that predominantly affects the renal and internal carotid arteries. However, the cause of this disease remains unclear. Radiological studies are important diagnostic methods, which generally involve luminal features on computed tomographic angiography, magnetic resonance angiography, and digital subtraction angiography. However, the high-resolution magnetic resonance imaging (HR-MRI) features of FMD have not yet been reported. Herein, we report the HR-MRI features of patients with FMD who showed typical involvement of the internal carotid arteries. Although both patients presented a beading appearance typical of medial fibroplasia, HR-MRI nevertheless showed distinct features. HR-MRI revealed concentric wall thickening and circular enhancement with dystrophic calcification in one and wall thickening, but no enhancement in the others. Further studies are required to determine whether these HR-MRI features are related to the type of FMD or patient prognosis.

Convergent molecular and structural neuroimaging signatures of first-episode depression

BackgroundConvergent studies have demonstrated morphological abnormalities in various brain regions in depression patients. However, the molecular underpinnings of the structural impairments remain largely unknown, despite a pressing need for treatment targets and mechanisms. Here, we investigated the gray matter volume (GMV) alteration in patients with depression and its underlying molecular architecture. MethodsWe recruited 195 first-episode, treatment-naïve depression patients and 78 gender-, age-, and education level-matched healthy controls (HCs) who underwent high-resolution T1-weighted magnetic resonance scans. Voxel-based morphometry (VBM) was adopted to calculate the GMV differences between two groups. Then we analyzed the spatial correlation between depression-induced alteration in GMV and density maps of 10 receptors/transporters deriving from prior molecular imaging in healthy people. ResultsCompared to HCs, the depression group had significantly increased GMV in the left ventral portions of the ventral medial prefrontal cortex, parahippocampal gyrus, amygdala, the right superior parietal lobule and precuneus while decreased GMV in the bilateral hippocampus extending to the thalamus and cerebellum. The GMV alteration introduced by depression was spatially correlated with serotonin receptors (5-HT1a, 5-HT1b, and 5-HT2a), dopamine receptors (D1 and D2) and GABAergic receptor (GABAa) densities. LimitationsThe conclusions drawn in this study were obtained from a single dataset. ConclusionsThis study reveals abnormal GMV alteration and provides a series of neurotransmitters receptors possibly related to GMV alteration in depression, which facilitates an integrative understanding of the molecular mechanism underlying the structural abnormalities in depression and may provide clues to new treatment strategies.

Isolation and Identification of Flavones Responsible for the Antibacterial Activities of Tillandsia bergeri Extracts.

Plants are an everlasting inspiration source of biologically active compounds. Among these medicinal plants, the biological activity of extracts from some species of the Tillandsia genus has been studied, but the phytochemistry of the hardy species Tillandsia bergeri remains unknown. The aim of the present study was to perform the first phytochemical study of T. bergeri and to identify the compounds responsible for the antibacterial activity of T. bergeri extracts. Soxhlet extraction of predried and grinded leaves was first performed using four increasing polarity solvents. A bio-guided fractionation was performed using agar overlay bioautography as a screening method against 12 Gram-positive, Gram-negative, sensitive, and resistant bacterial strains. The results showed the inhibition of Gram-positive methicillin-sensitive Staphylococcus aureus ATCC 29213 (MSSA), methicillin-resistant S. aureus N-SARM-1 (MRSA), and Staphylococcus caprae ATCC 35538 by the dichloromethane fraction. A phytochemical investigation led to the isolation and identification by high-resolution mass spectrometry and nuclear magnetic resonance of the two flavones penduletin and viscosine, responsible for this antibacterial activity. For viscosine, the minimum inhibitory concentration (MIC) value is equal to 128 μg/mL against MSSA and is equal to 256 μg/mL against MRSA and S. caprae. The combination of these compounds with vancomycin and cloxacillin showed a decrease in MICs of the antibiotics. Penduletin showed synergistic activity when combined with vancomycin against MSSA (FICI < 0.258) and S. caprae (FICI < 0.5). Thus, unexplored Tillandsia species may represent a valuable source for potential antibiotics and adjuvants.

Smoke point prediction of oxygenated fuels using neural networks

Smoke point (SP) is an important fuel property that characterizes the propensity of aviation jet fuels and kerosene to form soot. In the present study, an artificial neural network (ANN) model based on the artificial intelligence principle was developed to predict the SP of fuels with oxygenates (ethers and alcohols) and hydrocarbons (e.g., paraffins, olefins, naphthenes, aromatics, and their blends). An experimental dataset of 366 fuel mixtures comprising 113 pure compounds, 8 types of gasoline and diesels, and 245 fuel blends was used to improve the SP-prediction performance of the ANN model. One hundred and ten of the fuel blends used were various jet fuel surrogates collected from the literature. Experimental SP of 40 new mixtures consisting of diethyl ether, dibutyl ether, dioctyl ether, diphenyl ether, and methyl tert-butyl ether along with gasoline and diesel was measured as part of this work. The molecular composition of the fuels was expressed as the weight % of eight constituent functional groups present in the fuel. These functional groups along with two additional parameters (branching index and molecular weight) were provided as ten inputs to the model. The functional groups present in the gasoline and diesel samples were determined using high-resolution 1H nuclear magnetic resonance spectroscopy. The data were randomly split into three sets: training (70 %), validation (15 %), and test (15 %). The model was initially trained and validated simultaneously, and then; it was tested. A positive linear relation was observed between the measured and predicted SPs, as indicated by a correlation coefficient of 0.98. The mean absolute error of the predicted SP was 4.5. Results showed that the SP of the fuels depended on the aforementioned parameters that served as inputs for the model. The proposed model can be used to predict the SP of pure and blended form fuels containing the aforementioned functional groups.

Anatomically Accurate, High-Resolution Modeling of the Human Index Finger Using In Vivo Magnetic Resonance Imaging.

Anatomically accurate models of a human finger can be useful in simulating various disorders. In order to have potential clinical value, such models need to include a large number of tissue types, identified by an experienced professional, and should be versatile enough to be readily tailored to specific pathologies. Magnetic resonance images were acquired at ultrahigh magnetic field (7 T) with a radio-frequency coil specially designed for finger imaging. Segmentation was carried out under the supervision of an experienced radiologist to accurately capture various tissue types (TTs). The final segmented model of the human index finger had a spatial resolution of 0.2 mm and included 6,809,600 voxels. In total, 15 TTs were identified: subcutis, Pacinian corpuscle, nerve, vein, artery, tendon, collateral ligament, volar plate, pulley A4, bone, cartilage, synovial cavity, joint capsule, epidermis and dermis. The model was applied to the conditions of arthritic joint, ruptured tendon and variations in the geometry of a finger. High-resolution magnetic resonance images along with careful segmentation proved useful in the construction of an anatomically accurate model of the human index finger. An example illustrating the utility of the model in biomedical applications is shown. As the model includes a number of tissue types, it may present a solid foundation for future simulations of various musculoskeletal disease processes in human joints.

Local Structure and Protons in Non-Stoichiometric Pseudo-Cubic Pollucite Mineral by Multinuclear NMR

The pollucite structure is considered as a candidate ceramic crystalline matrix for the ceramic immobilization and long-term storage of 135Cs and 137Cs fission products, and thus, their structural characteristics have particular importance. However, its local structure has not been fully resolved from reciprocal-space techniques and infrared spectroscopy, and important discrepancies exist in the available literature. Two birefringent and non-stoichiometric pollucite specimens from Tanco pegmatite (Cs0.83Na0.20Al1.13Si2.56O6) and from Mt. Mica pegmatite (Cs0.94Na018Al1.23Si2.78O6), with powder X-ray diffraction patterns fully consistent with the cubic Ia-3d space-group symmetry, and with a very different degree of hydrothermal alteration, were used in this work. High-resolution magic-angle spinning multinuclear magnetic resonance (MAS NMR) spectroscopy, including 29Si, 27Al, 23Na, 133Cs, and 1H spectra at 9.4 T, as well as 1H, 27Al, 27Al{1H} dipolar evolutions and 27Al{29Si} Heteronuclear Multiple Quantum Coherence (HMCQ) spectra at 17.6 T, has been used to investigate the local structure of pollucite and the role of protons. The 29Si spectra suggest a local structure with a disordered Si/Al distribution in only one tetrahedral T site, but with a preference of Si atoms for Q41 (3Si,1Al) and Q42 (2Si,2Al) environments, in comparison with random and Loewenstein distributions, due to charge dispersion effects. However, the 27Al{1H} dipolar evolutions suggest two spectroscopically distinct T sites for Al atoms. The 23Na and 133Cs spectra indicate broad site distributions for these cavity cations. The anisotropic character of the long-range disordered pollucite structure, with a pseudo-cubic symmetry and lack of strict periodicity, can be explained from an incipient displacive transition to lower symmetry. These pollucite specimens are essentially anhydrous minerals despite the 1H and the cross-polarization experiments suggesting that some protons exist in the structure as -OH groups, whereas water molecules were only found in relation to the phyllosilicate impurities from alteration in specimen Tanco and perhaps also as liquid water in fluid inclusions.

Structural Characterization of Peripolin and Study of Antioxidant Activity of HMG Flavonoids from Bergamot Fruit.

The structural characterization of a new flavonoid from bergamot fruit (Citrus bergamia Risso) carrying the 3-hydroxy-3-methyl glutaryl (HMG) ester moiety has been accomplished, and its antioxidant ability was tested from a chemical point of view. The peculiarity of the new molecule, named peripolin, relies on the presence of the HMG chemical group linked to the sugar portion of neoeriocitrin; the structure was elucidated using both high-resolution mass spectrometry and nuclear magnetic resonance experiments performed on the purified molecule extracted from the fruit. The antioxidant ability of the new molecule was tested by classical chemical approaches, such as DPPH, ABTS and FRAP assays, and from a theoretical point of view. 1H and 13C NMR experiments and HR-ESI-MS/MS experiments show unequivocally that the HMG moiety is linked to the primary position of the glucose unit of neohesperidose, while the chemical tests and the computational results show that peripolin possesses strong antioxidant behavior, similar to that of neoeriocitrin and remarkably higher respect to the other flavonoids present in the fruit. Furthermore, the quantitative assays carried out by UPLC-MS/MS showed that its amount in the fruit is similar to that of the other main flavonoids. Furthermore, molecular dynamics simulations allowed us to investigate the possible conformations adopted by the antioxidants in the presence of water molecules. In particular, the switch of open-closed conformations of HMG-containing species was evidenced. As far as the reaction with DPPH, the calculation of ΔGrea supported the experimental outcomes regarding the peripolin and neoeriocitrin activity. In conclusion, bergamot fruit, already known for its potential to lower the level of blood cholesterol, has been proven to contain molecules such as neoeriocitrin and the newly characterized peripolin, which could have important in-vivo antioxidant characteristics.

Assessment of Morphological Features and Imaging Characteristics of Patients with Intracranial Artery Dissection: A High-Resolution MRI Study

Intracranial artery dissection (IAD) is a pathological dissection of the arterial wall. .However, the morphological features and imaging characteristics of patients with intracranial artery dissection (IAD) remain poorly understood. The study reports on 70 IAD patients (30 culprit and 40 non-culprit). All participants underwent high-resolution magnetic resonance imaging (HR-MRI) scans. The morphological features and imaging characteristics of artery dissection were carefully investigated. Demographics and clinical characteristics of culprit and non-culprit patients were also collected. Apparent differences between the two groups, which could be used as biomarkers for ischemic event caused by the culprit dissection, were identified by receiver operating characteristic (ROC) curve analysis. The IAD patients studied could be classified into five different types on the basis of morphological features: classical dissection (n = 31), fusiform aneurysm (n = 2), long dissected aneurysm (n = 9), dolichoectatic dissecting aneurysm (n = 6), and saccular aneurysm (n = 22). The direct sites of artery dissection (double lumen and intimal flap) can be seen in most IAD patients on HR-MRI. Additionally, the presence of hypertension, double lumen and intimal flap were associated with culprit lesions and might be considered biomarkers for the ischemic event caused by the culprit dissection. Analysis showed that HR-MRI allowed easy visualization of abnormal morphology of artery dissection lesions. This was of great significance for the diagnosis of IAD and gave a better understanding of its pathophysiological mechanism.

The transdiagnostic relationship of cumulative lifetime stress with memory, the hippocampus, and personality psychopathology

Stress has a detrimental impact on memory, the hippocampus, and psychological health. Psychopathology research on stress has centered mainly on psychiatric diagnoses rather than symptom dimensions, and less attention has been given to the neurobiological factors through which stress might be translated into psychopathology. The present work investigates the transdiagnostic relationship of cumulative stress with episodic memory and the hippocampus (both structure and function) and explores the extent to which stress mediates the relationship between personality psychopathology and hippocampal size and activation. Cumulative lifetime stress was assessed in a sample of females recruited to vary in stress exposure and severity of personality psychopathology. Fifty-six participants completed subjective and objective tests of episodic memory, a T2-weighted high-resolution magnetic resonance imaging (MRI) scan of the medial-temporal lobe, and functional MRI (fMRI) scanning during a learning and recognition memory task. Higher cumulative stress was significantly related to memory complaints (but not episodic memory performance), lower bilateral hippocampal volume, and greater encoding-related hippocampal activation during the presentation of novel stimuli. Furthermore, cumulative stress significantly mediated the relationship between personality psychopathology and both hippocampal volume and activation, whereas alternative mediation models were not supported. The findings suggest that structural and functional activation differences in the hippocampus observed in case-control studies of psychiatric diagnoses may share cumulative stress as a common factor, which may mediate broadly reported relationships between psychopathology and hippocampal structure and function.