Ultrasound and MR imaging of peripheral nerve tumors: the state of the art.

Peripheral nerve sheath tumors are a heterogeneous subgroup of soft tissue tumors that either arise from a peripheral nerve or show nerve sheath differentiation. On imaging, direct continuity with a neural structure or location along a typical nerve distribution represents the most important signs to suggest the diagnosis. Ultrasound and magnetic resonance imaging are the best modalities to evaluate these lesions. First, it is necessary to differentiate between a true tumor and a non-neoplastic nerve condition such as a neuroma, peripheral nerve ganglion, intraneural venous malformation, lipomatosis of nerve, or nerve focal hypertrophy. Then, with a combination of clinical features, conventional and advanced imaging appearances, it is usually possible to characterize neurogenic tumors confidently. This article reviews the features of benign and malignant peripheral nerve sheath tumors, including the rare and recently described tumor types. Furthermore, other malignant neoplasms of peripheral nerves as well as non-neoplastic conditions than can mimick neurogenic tumor are herein discussed.

Interfacial tension of ethanol, water, and their mixtures in high pressure carbon dioxide: Measurements and modeling.

HYPOTHESIS: It is particularly noteworthy to study interfacial tension behavior under pressurized carbon dioxide for supercritical processes such as crystallization or fractionation. For the latter, a liquid phase and a supercritical phase are in contact, and interfacial properties influence mass transfer phenomena and hydrodynamics. Ethanol-water mixture is a good theoretical study case also involved in a wide range of applications. EXPERIMENTAL: Interfacial tensions of ethanol, water and three mixtures, with an ethanol mass fraction from 0.25 to 0.75, under pressurized CO2 were measured for pressures ranging from 0.1 MPa to 15.1 MPa at 313.15 K and 333.15 K. A specific experimental set-up was used for CO2 phase saturation. FINDINGS: This work brings interfacial tension data of five different solutions including water and ethanol in contact with CO2. Effects of pressure, temperature, carbon dioxide density and ethanol mass fraction are discussed regarding the literature. Significant discrepancies are found with previous literature data for ethanol-water mixtures. The "two-step" decrease observed when pressure or density increase is also discussed regarding both the concept of Widom line, and the polar and dispersive contributions of the surface tension of a component. For the first time, fair accurate interfacial tension modeling involving these contributions is addressed.

Surfactant Protection Efficacy at Surfaces Varies with the Nature of Hydrophobic Materials.

OBJECTIVE: Monoclonal antibodies are in contact with many different materials throughout their life cycle from production to patient administration. Plastic surfaces are commonly found in single use bags, syringes, perfusion bags and tubing and their hydrophobic nature makes them particularly prone for adsorption of therapeutic proteins. The addition of surfactants in therapeutic formulations aims at minimizing surface and interface adsorption of the active molecules. However, their protection efficacy related to the nature of the plastic material is still poorly investigated. METHODS: We use real-time surface-sensitive techniques and immunosorbent assays, to quantify surfactant and monoclonal antibody adsorption on hydrophobic model surfaces and different plastic polymers to analyse the effect of material surface properties on the level of surfactant protection. RESULTS: We show that Polysorbate 80 protects monoclonal antibodies significantly better from adsorption on a polystyrene surface than on a hexadecane self-assembled monolayer, used as a model surface with similar hydrophobicity. This enhanced protective effect on polystyrene is observed for different antibodies and also other surfactants, and its extent depends on the surfactant concentration for a given antibody concentration. A comparative adsorption study allows ranking different in-use plastics and highlights the dependence of Polysorbate 80 protection efficacy on the nature of the plastic material. CONCLUSION: This study demonstrates that, beyond hydrophobicity, the nature of plastic polymer surfaces affects surfactant adsorption and thereby impacts their protection efficacy in therapeutic antibody formulations.

Main Diagnostic Pitfalls in Reading the Sacroiliac Joints on MRI.

Magnetic resonance imaging of the sacroiliac joints is now frequently performed to help identify patients with early axial spondyloarthritis. However, differential diagnoses exist and should be recognized. The aim of this article is to review the most frequent differential diagnoses that may mimic inflammatory sacroiliitis in clinical practice.

Correction: Galenic lab-on-a-chip concept for lipid nanocapsules production.

Correction for 'Galenic Lab-on-a-Chip concept for lipid nanocapsules production' by Nicolas Rolley et al., Nanoscale, 2021, 13, 11899-11912, DOI: 10.1039/D1NR00879J.

Galenic Lab-on-a-Chip concept for lipid nanocapsules production.

The continuous production of drug delivery systems assisted by microfluidics has drawn a growing interest because of the high reproducibility, low batch-to-batch variations, narrow and controlled particle size distributions and scale-up ease induced by this kind of processes. Besides, microfluidics offers opportunities for high throughput screening of process parameters and the implementation of process characterization techniques as close to the product as possible. In this context, we propose to spotlight the GALECHIP concept through the development of an instrumented microfluidic pilot considered as a Galenic Lab-on-a-Chip to formulate nanomedicines, such as lipid nanocapsules (LNCs), under controlled process conditions. In this paper we suggest an optimal rational development in terms of chip costs and designs. First, by using two common additive manufacturing techniques, namely fused deposition modelling and multi-jet modelling to prototype customized 3D microfluidic devices (chips and connectors). Secondly, by manufacturing transparent Silicon (Si)/Glass chips with similar channel geometries but obtained by a new approach of deep reactive ion etching (DRIE) technology suitable with in situ small angle X-ray scattering characterizations. LNCs were successfully produced by a phase inversion composition (PIC) process with highly monodispersed sizes from 25 nm to 100 nm and formulated using chips manufactured by 3D printing and DRIE technologies. The transparent Si/Glass chip was also used for the small angle X-ray scattering (SAXS) analysis of the LNC formulation with the PIC process. The 3D printing and DRIE technologies and their respective advantages are discussed in terms of cost, easiness to deploy and process developments in a GALECHIP point of view.

Adsorption rate constants of therapeutic proteins and surfactants for material surfaces.

Adsorption of therapeutic proteins to material surfaces can be a pivotal issue in drug development, especially for low concentration products. Surfactants are used to limit adsorption losses. For each formulation component, surface adsorption is the result of a combination of its diffusion and surface adsorption rates. The latter are difficult to measure accurately because a depletion layer forms rapidly in the bulk solution above a bare surface, slowing down adsorption. Adapting flow conditions and local surface chemistry, we are able to minimize depletion limitations and measure apparent adsorption rate constants of three monoclonal antibodies, other proteins and surfactants with a hydrophobic surface. We show that surface adsorption rates scale with the molecular mass of the molecule, with polysorbates therefore showing thousand times slower rates than antibodies. Moreover, we observed that the desorption dynamic of polysorbates from a given hydrophobic surface depends on surface coverage, whereas this is not the case for Poloxamer 188. These novel contributions to surface adsorption dynamics enable a new perspective on the evaluation of drug surface compatibility and can, together with diffusion rates, be used to predict the protective potential of surfactants in given conditions.

Medial meniscal ossicles: Associated knee MRI findings in a multicenter case-control study.

PURPOSE: The purpose of this study was to assess and compare the prevalence of meniscal, ligament and cartilage lesions on knee MRI in a series of age- and sex-matched patients with and without medial meniscal ossicle. MATERIALS AND METHODS: Forty-two knee MRI examinations obtained in 42 patients (36 men, 6 women; mean age, 42.5±22.2 [SD] years; range: 19-65years) on which a medial meniscal ossicle was present were compared to 42 knee MRI examinations obtained in 42 age- and sex-matched patients (36 men, 6 women; mean age, 41.8±20.6 [SD] years; range: 19-65years) on which no medial meniscal ossicles were present. Two radiologists (R1, R2) blinded to the presence of meniscal ossicle by reading only the fat-saturated intermediate-weighted MR images separately assessed the presence of meniscal, ligament and cartilage lesions on these 84 knee MRI examinations. Prevalence of meniscal and ligament lesions and degree of cartilage degradation at MRI were compared between knees with and those without medial meniscal ossicle. RESULTS: In knees with medial meniscal ossicle, R1 and R2 detected 33 (79%) and 38 (90%) medial meniscal lesions, respectively that involved the posterior root (n=25/32 for R1/R2), the posterior horn (n=19/14 for R1/R2) or the body (n=8/10 for R1/R2). The prevalence of posterior root tear (60% [25/42]/76% [32/42] for R1/R2) and that of anterior cruciate ligament (ACL) lesions (48% [20/42]/57% [24/42] for R1/R2) as well as the medial cartilage degradation score (3.35±0.87 [SD] for R1 and 3.92±0.78 [SD] for R2) were significantly greater in knees with than in knees without medial meniscal ossicle (root lesions: P<0.01 for both readers; ACL lesions and medial cartilage score: P<0.01 for both readers). CONCLUSION: On MRI examination, knees with a medial meniscal ossicle demonstrate a greater frequency of medial posterior root tear and of ACL lesions and a greater degree of medial femoro-tibial cartilage degradation by comparison with knees without medial ossicle.

Synthesis of PDMS-b-POEGMA Diblock Copolymers and Their Application for the Thermoresponsive Stabilization of Water-Supercritical Carbon Dioxide Emulsions.

In this study, PDMS13-b-POEGMAx diblock copolymers consisting of a CO2-philic poly(dimethylsiloxane) (PDMS) block connected to a thermosensitive hydrophilic poly(oligoethylene glycol methacrylate) (POEGMA) block were synthesized by reversible addition-fragmentation chain-transfer (RAFT) radical polymerization. Their ability to decrease the water-supercritical CO2 (scCO2) interfacial tension (γ) and to stabilize water-scCO2 emulsions was investigated using an original homemade device developed in the laboratory. This device is able to control the pressure from 1 to 250 bar and the temperature from 40 to 80 °C. It was implemented with 2 visualization windows, a drop tensiometer and a remote optical head for dynamic light scattering (DLS) measurements. These experiments revealed that PDMS-b-POEGMA decreased γ down to 1-2 mN/m and was the most efficient at high pressure (250 bar) and low temperature (40 °C) where PDMS and POEGMA blocks exhibited the highest affinity for their respective phase. The diblock copolymers were shown to stabilize water-scCO2 emulsions. Moreover, the thermosensitive behavior of the POEGMA block in water (with a lower critical solubility temperature around 65 °C) resulted in the formation of temperature-responsive emulsions that could reversibly switch at 100 bar from stable at 40 °C to unstable at 80 °C. These results were rationalized based on the solubility of each individual block of the copolymers in water and scCO2 as a function of temperature and pressure.

Thoracic Outlet Syndrome: Diagnostic Accuracy of MRI.

BACKGROUND: Thoracic outlet syndrome (TOS) is challenging to diagnose, as the physical findings and investigations lack sensitivity and/or specificity. Magnetic resonance imaging (MRI) with dynamic manoeuvres can rule out a tumour and detect anatomical abnormalities potentially responsible for compression. The objective of this study was to assess the sensitivity and specificity of MRI for identifying anatomical structures responsible for compression in TOS, using intra-operative findings as the diagnostic reference standard. HYPOTHESIS: MRI is effective in diagnosing the source of compression in TOS, notably within the scalene triangle and at the pleural apex. METHODS: We retrospectively included 48 patients who underwent surgery for TOS after a work-up that included MRI (1.5-T, n=29 and 3-T, n=19). The MRI scans were reviewed for the study by a specialised radiologist who was unaware of the intra-operative findings. The sensitivity and specificity of MRI for diagnosing TOS were estimated using the intra-operative findings as the reference standard. RESULTS: MRI identified a structure potentially responsible for TOS in 34 (71%) patients; thus, the false-negative rate was 14/48 (29%). The sensitivity of MRI was 28% for compression at the suspensory ligament of the pleural dome, 81% for hypertrophy of the anterior scalene muscle, and 50% for an accessory scalene muscle. For diagnosing a cervical rib, MRI had 100% sensitivity and 100% specificity. CONCLUSION: MRI can contribute to the diagnosis of TOS. Specificity is sufficiently high to provide guidance for planning the surgical procedure. Sensitivity, however, is too low for MRI to be useful as a screening test. MRI should be used in combination with the clinical assessment and other investigations to assist in the diagnosis of TOS. LEVEL OF EVIDENCE: IV, retrospective cohort study.

Joint Effusion and Bone Outlines of the Knee: Radiographic/MR Imaging Correlation.

Knee radiographs are widely used in clinical practice. Many features can be depicted when a systematic analysis of the different views is performed. This article focuses on different types of joint effusion and on the analysis of the bone outlines of the knee, particularly on the lateral view. Systematic analysis of these bone outlines and knowledge of several key points are particularly useful for the depiction of abnormal bone morphology or positioning, and of several conditions, such as trochlear dysplasia, patellar dislocation, impaction fractures, or ligament injuries and avulsion fractures.

Exercise referral schemes enhanced by self-management strategies to reduce sedentary behaviour and increase physical activity among community-dwelling older adults from four European countries: protocol for the process evaluation of the SITLESS randomised controlled trial.

INTRODUCTION: SITLESS is a randomised controlled trial determining whether exercise referral schemes can be enhanced by self-management strategies to reduce sedentary behaviour and increase physical activity in the long term, in community-dwelling older citizens. The intervention is complex and requires a process evaluation to understand how implementation, causal mechanisms and context shape outcomes. The specific aims are to assess fidelity and reach of the implementation, understand the contextual aspects of each intervention site, evaluate the mechanisms of impact, and explore perceived effects. METHODS AND ANALYSIS: Following the Medical Research Council guidance on complex interventions, a combination of qualitative and quantitative procedures is applied, including observational checklists and attendance registries, standardised scales (ie, Marcus's Self-Efficacy Questionnaire, Physical Activity Self-Regulation Scale and the Lubben Social Network Scale) at baseline, postintervention and follow-up assessments, semistructured questionnaires gathering contextual characteristics, and participant observations of the sessions. Semistructured interviews and focus groups with the participants and trainers are conducted at postintervention and during the follow-up to explore their experiences. Outcomes from the standardised scales are analysed as moderators within the impact evaluation. Descriptive results on context and perceived effects complement results on impact. The qualitative and quantitative findings will help to refine the logic model to finally support the interpretation of the results on the effectiveness of the intervention. ETHICS AND DISSEMINATION: The study design was approved by the respective Ethical Committee of Ramon Llull University, Southern Denmark, Northern Ireland and Ulm University. Participation is voluntary, and all participants are asked to sign informed consent before starting the study. A dissemination plan operationalises how to achieve a social impact by reaching academic and non-academic stakeholders. A data management plan describes the specific data sets and regulates its deposition and curation. All publications will be open access. TRIAL REGISTRATION NUMBER: NCT02629666; Pre-results.

Sacroiliac joints: anatomical variations on MR images.

OBJECTIVE: To describe the appearance of the anatomical variations of the sacroiliac joints (SIJ) on MR images and to highlight the potential MR features that might be misleading. METHODS: Consecutive MRI examinations of SIJs performed at our department from January 2015 to December 2016 were retrospectively analyzed. As one of our goals was to describe potential misleading edematous or structural changes associated with SIJ anatomical variations, patients fulfilling the ASAS criteria were excluded from this study to ensure that signal intensity changes would not be related to sacroiliitis. Five anatomical variations and a dysmorphic appearance of the SIJ were detected. RESULTS: The final group consisted of 157 patients. Unilateral or bilateral anatomical variations of the SIJ were found in 50 patients (accessory SIJ, iliosacral complex and sacral defect in 17, 18 and 21 patients, respectively, and synostosis in one patient). A dysmorphic appearance of the SIJ was found in 26 patients. No case of an unfused ossification centers was depicted. Structural and/or edematous changes of the facing bones were quite frequently observed in accessory and dysmorphic SIJ. Iliosacral complex and sacral defects could be associated with prominent vessels running along their bony surfaces. CONCLUSION: Several anatomical variations of the SIJs are relatively commonly seen on MR images, particularly in females. These variations may be associated with signal intensity changes, which may be mechanical and not necessarily inflammatory in nature. KEY POINTS: • Anatomical variations of SIJ may involve the cartilaginous or ligamentous part of the joint • Anatomical variations of SIJ are sometimes associated with edematous and/or structural changes of the adjacent bone • Anatomical variations of the SIJ can be misleading on MR imaging.

Relationships between anhedonia, suicidal ideation and suicide attempts in a large sample of physicians.

BACKGROUND: The relationships between anhedonia and suicidal ideation or suicide attempts were explored in a large sample of physicians using the interpersonal psychological theory of suicide. We tested two hypotheses: firstly, that there is a significant relationship between anhedonia and suicidality and, secondly, that anhedonia could mediate the relationships between suicidal ideation or suicide attempts and thwarted belongingness or perceived burdensomeness. METHODS: In a cross-sectional study, 557 physicians filled out several questionnaires measuring suicide risk, depression, using the abridged version of the Beck Depression Inventory (BDI-13), and demographic and job-related information. Ratings of anhedonia, perceived burdensomeness and thwarted belongingness were then extracted from the BDI-13 and the other questionnaires. RESULTS: Significant relationships were found between anhedonia and suicidal ideation or suicide attempts, even when significant variables or covariates were taken into account and, in particular, depressive symptoms. Mediation analyses showed significant partial or complete mediations, where anhedonia mediated the relationships between suicidal ideation (lifetime or recent) and perceived burdensomeness or thwarted belongingness. For suicide attempts, complete mediation was found only between anhedonia and thwarted belongingness. When the different components of anhedonia were taken into account, dissatisfaction-not the loss of interest or work inhibition-had significant relationships with suicidal ideation, whereas work inhibition had significant relationships with suicide attempts. CONCLUSIONS: Anhedonia and its component of dissatisfaction could be a risk factor for suicidal ideation and could mediate the relationship between suicidal ideation and perceived burdensomeness or thwarted belongingness in physicians. Dissatisfaction, in particular in the workplace, may be explored as a strong predictor of suicidal ideation in physicians.

Assessment of the zonal variation of perfusion parameters in the femoral head: a 3-T dynamic contrast-enhanced MRI pilot study.

OBJECTIVE: The objective was to describe MR perfusion characteristics of the femoral head, with a focus on the subchondral bone. MATERIALS AND METHODS: This prospective monocentric study was approved by our local Ethics Committee. Written informed consent was obtained from all subjects. Dynamic contrast-enhanced MRI of the right hip was performed in 59 adults with suspected spondyloarthritis (32 women, 28 men). Mean age was 37.5 (±12.5) years. Regions of interest were drawn in the femoral head epiphysis, in the subchondral areas the most exposed to mechanical load (superolateral, anterosuperior, and posterior zones) and in areas less exposed to mechanical load (inferior subchondral zone and center of the femoral head). Semi-quantitative and pharmacokinetic parameters were calculated using the Tofts model. Statistical analysis was performed with a linear mixed model to compare the perfusion parameters in the different femoral head zones. RESULTS: Extravascular extracellular volume and area under the curve were lower in the superolateral zone than in the inferior zone (p = 0.0135 and p < 0.0001 respectively) and the central zone (p = 0.007 and p = 0.0134 respectively). Extravascular extracellular volume and rate constant were lower in the anterosuperior zone than in the inferior zones (p = 0.011 and p = 0.029). In the anterosuperior zone, extravascular extracellular volume was lower, and time to peak was higher than in the central zones (p = 0.0056 and p = 0.0013 respectively). No significant differences were found for any values between other paired zones. CONCLUSION: The perfusion of femoral head subchondral bone assessed with dynamic contrast-enhanced magnetic resonance imaging is not homogeneous: the areas exposed to more mechanical loading are less perfused.

Conventional Radiology in Crystal Arthritis: Gout, Calcium Pyrophosphate Deposition, and Basic Calcium Phosphate Crystals.

This article reviews the main radiographic features of crystal deposition diseases. Gout is linked to monosodium urate crystals. Classic radiographic features include subcutaneous tophi, large and well-circumscribed paraarticular bone erosions, and exuberant bone hyperostosis. Calcium pyrophosphate deposition (CPPD) can involve numerous structures, such as hyaline cartilages, fibrocartilages, or tendons. CPPD arthropathy involves joints usually spared by osteoarthritis. Basic calcium phosphate deposits are periarticular or intraarticular. Periarticular calcifications are amorphous, dense, and round or oval with well-limited borders, and most are asymptomatic. When resorbing, they become cloudy and less dense with an ill-defined shape and can migrate into adjacent structures.

Anatomical and MR correlative study of the proximal sciatic nerve vasculature.

OBJECTIVE: The aim of our study is to demonstrate that increased T2 signal on MRI could be due to intraneural vessels in asymptomatic individuals, and may therefore be a normal finding. METHODS: An initial anatomic cadaveric study was undertaken to gain a better understanding of the vascular supply of the proximal sciatic nerve. Secondly, a retrospective study of MR imaging of patients without sciatic symptoms was performed to assess the prevalence of intraneural vessels, defined as hyperintensity on at least three consecutive slices on both T2 and gadolinium enhanced T1 weighted imaging, visible on routine MSK pelvic imaging. RESULTS: The anatomical study demonstrated a relatively abundant blood supply in the peri-ischiatic region. In the MR study, 20/76 (26%) patients showed visible intraneural vessels. More than one intraneural vessel was depicted in two of the sciatic nerves. Direct branching between the extrinsic and intrinsic systems was seen in only five cases. CONCLUSION: Normal intraneural vessels can frequently be seen within the sciatic nerve on routine musculoskeletal pelvic imaging. Advances in knowledge: T2 hyperintensity in the proximal sciatic nerve can be due to intraneural vessels and should not necessarily be reported as abnormal.

T2 Mapping of the Sacroiliac Joints With 3-T MRI: A Preliminary Study.

OBJECTIVE: The objective of this study was to assess the feasibility of T2 relaxation time measurements of the sacroiliac joints. SUBJECTS AND METHODS: The sacroiliac joints of 40 patients were imaged by 3-T MRI using an oblique axial multislice multiecho spin-echo T2-weighted sequence. Manual plotting and automatic subdivision of ROIs allowed us to obtain T2 values for up to 48 different areas per patient (posterior and anterior parts, sacral, intermediate, and iliac parts). Intraand interobserver reproducibility of T2 values were calculated after independent assessment by two musculoskeletal radiologists. RESULTS: A total of 1656 measurement sites could be analyzed. Mean (± SD) T2 values were 40.6 ± 6.7 ms and 41.2 ± 6.3 ms for observer 1 and 39.9 ± 6.6 ms for observer 2. The intraobserver intraclass correlation coefficient was 0.72 (95% CI, 0.70-0.74), and the interobserver intraclass correlation coefficient was 0.71 (95% CI, 0.68-0.72). CONCLUSION: Our study shows the feasibility of T2 relaxation time measurements at the sacroiliac joints.