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Articular cartilage and meniscus transfer and distribute mechanical loads in the knee joint. Degeneration of these connective tissues occurs during the progression of knee osteoarthritis, which affects their composition, microstructure, and mechanical properties. A deeper understanding of disease progression can be obtained by studying them simultaneously. Time-resolved synchrotron-based X-ray phase-contrast tomography (SR-PhC-µCT) allows to capture the tissue dynamics. This proof-of-concept study presents a rheometer setup for simultaneous in situ unconfined compression and SR-PhC-µCT of connective knee tissues. The microstructural response of bovine cartilage (n = 16) and meniscus (n = 4) samples under axial continuously increased strain, or two steps of 15% strain (stress-relaxation) is studied. The chondrocyte distribution in cartilage and the collagen fiber orientation in the meniscus are assessed. Variations in chondrocyte density reveal an increase in the top 40% of the sample during loading, compared to the lower half. Meniscus collagen fibers reorient perpendicular to the loading direction during compression and partially redisperse during relaxation. Radiation damage, image repeatability, and image quality assessments show little to no effects on the results. In conclusion, this approach is highly promising for future studies of human knee tissues to understand their microstructure, mechanical response, and progression in degenerative diseases., (© 2024 The Authors. Advanced Science published by Wiley‐VCH GmbH.)

This study investigates the polarimetric properties of skin, skeletal muscle, connective tissue, and fat using Mueller matrix imaging. It aims to compare the polarimetric characteristics of these tissues and explore how they evolve with wavelength. Additionally, the temporal evolution of certain tissues during meat aging is studied, providing insights into the dynamic behavior of polarimetric properties over time. The research employs back-scattering configuration and the differential decomposition analysis method of Mueller matrix images. Both in-vivo and ex-vivo experiments were conducted using a consistent instrument setup to ensure reliable analysis. The results reveal wavelength-dependent variations in tissue properties, including an increase in depolarization with wavelength. Significant differences in the polarimetric characteristics of meat tissues, particularly for skeletal muscle, are observed. Over a 24-h period, intensity, diattenuation, and retardation experience alterations, being the decreased retardation in skeletal muscle and the increased retardation in fat the most notable ones., (© 2023 The Authors. Journal of Biophotonics published by Wiley-VCH GmbH.)

Objectives: Non-inflammatory thickening of the subsynovial connective tissue (SSCT) in the carpal tunnel is commonly found in subjects with carpal tunnel syndrome (CTS), and quantification may shed light on CTS pathogenesis. To date, information on the reliability of ultrasound quantification of SSCT is scarce. Therefore, we investigated intrarater and interrater reliability/agreement for ultrasound quantification of SSCT thickness in subjects with and without CTS, and predictors for tissue thickness., Material and Methods: Two investigators quantified SSCT thickness and thickness ratio on ultrasound in 16 healthy subjects (age, 24-65 years; 16 left/14 right wrists) and 17 subjects with CTS (age, 37-83 years; 14 left/14 right wrists). Intra- and inter-rater reliability/agreement were assessed on intraclass correlation coefficients, standard error of measurement and minimal detectable change. A mixed-effects model was used to evaluate potential predictors for SSCT thickness., Results: Intra- and inter-rater reliability analysis showed good to excellent intraclass correlation coefficients in both groups, ranging from 0.772 to 0.965. The maximum percentage standard error of measurement was 8%. The maximum minimal detectable change was 14% within raters, and 20% between raters. Both intra- and inter-rater reliability values for thickness ratio were poor. Presence of CTS (ß = 0.180; p = 0.015) correlated positively with SSCT thickness., Conclusions: Ultrasound is a reliable method for quantification of SSCT thickness, but not for thickness ratio. Presence of CTS correlates positively with SSCT thickness., (Copyright © 2023 SFCM. Published by Elsevier Masson SAS. All rights reserved.)

The subsynovial connective tissue is an integral component of flexor tendon gliding in the carpal tunnel, which is strained during longitudinal tendon displacement. We tested the effects of repetition frequency and finger load on flexor tendon function throughout active finger movement. Eleven participants performed metacarpophalangeal joint flexion/extension of the long finger cyclically at three repetition frequencies (0.75, 1.00, 1.25 Hz) and two finger loads (3.5, 7 N). Relative displacement between the flexor digitorum superficialis tendon and subsynovial connective tissue was assessed as the shear-strain index with color ultrasound throughout the entire time history of finger flexion and extension. In addition, long finger joint angles were measured with electrogoniometry while flexor digitorum superficialis and extensor digitorum muscle activities were measured with fine-wire electromyography to characterize the finger movements. The shear-strain index increased with greater finger flexion (p = 0.001), representing higher relative displacement between tendon and subsynovial connective tissue; however, no changes were observed throughout finger extension. The shear-strain index also increased with higher repetition frequencies (p = 0.013) and finger loads (p = 0.029), further modulating time-dependent effects during finger flexion versus extension. Using ultrasound, we characterized the time-dependent response of the shear-strain index, in vivo, providing valuable data on flexor tendon function during active finger movement. Our results infer greater subsynovial connective tissue strain and shear during repetitive and forceful finger movements. Future research characterizing time-dependent effects in carpal tunnel syndrome patients may further elucidate the relations between subsynovial connective tissue function, damage, and carpal tunnel syndrome., (© 2023 The Authors. Journal of Orthopaedic Research® published by Wiley Periodicals LLC on behalf of Orthopaedic Research Society.)

A painful, chronic condition, Rheumatoid Arthritis, is marked by bone erosion and soft tissue swelling at the joint. As treatments are investigated in pre-clinical models, characterizing disease progression is integral to assessing treatment efficacy. Here, in vivo and ex vivo micro-computed tomography (µCT) are used in parallel with traditional caliper score measurement to quantify physiological changes in the tarsal region in a murine, collagen-induced arthritis model. In vivo imaging methods, which are validated here through comparison to ex vivo and caliper methods, afford longitudinal analysis of both bone and soft tissue through a single image acquisition. This method removes the subjectivity of swelling quantification which is inherently associated with traditional caliper measurements. Histopathology offers an additional assessment of bone erosion and inflammation by providing a microscopic characterization of disease activity. In comparison to untreated animals, daily prednisolone (glucocorticoid) treatment is shown to restore bone volume, as reflected through in vivo and ex vivo µCT images, as well as histopathology. Prednisolone-associated reduction in inflammation is shown through in vivo µCT soft tissue volume measurements, paw caliper measurements, and histopathology. The findings reported here provide a comprehensive validation of in vivo µCT with a sensitivity that enables characterization of pre-clinical disease assessment in response to treatment in a murine, collagen-induced arthritis model., (© 2022. The Author(s).)

Bone fractures commonly repair by forming a bridging structure called callus, which begins as soft tissue and gradually ossifies to restore rigidity to the bone. Virtual mechanical testing is a promising technique for image-based assessment of structural bone healing in both preclinical and clinical settings, but its accuracy depends on the validity of the material model used to assign tissue mechanical properties. The goal of this study was to develop a constitutive model for callus that captures the heterogeneity and biomechanical duality of the callus, which contains both soft tissue and woven bone. To achieve this, a large-scale optimization analysis was performed on 2363 variations of 3D finite element models derived from computed tomography (CT) scans of 33 osteotomized sheep under normal and delayed healing conditions. A piecewise material model was identified that produced high absolute agreement between virtual and physical tests by differentiating between soft and hard callus based on radiodensity. The results showed that the structural integrity of a healing long bone is conferred by an internal architecture of mineralized hard callus that is supported by interstitial soft tissue. These findings suggest that with appropriate material modeling, virtual mechanical testing is a reliable surrogate for physical biomechanical testing., (© 2022. The Author(s).)

Objective: To test whether the presence of structural entheseal lesions in psoriasis patients influences the risk of progression to psoriatic arthritis (PsA)., Methods: We conducted a prospective cohort study of psoriasis patients without clinical evidence of musculoskeletal involvement who underwent baseline assessment of structural entheseal lesions and volumetric bone mineral density (vBMD) at entheseal and intraarticular sites by high-resolution peripheral quantitative computed tomography. Adjusted relative risks of developing PsA associated with baseline vBMD and the presence of structural entheseal lesions were calculated using multivariable Cox regression models., Results: The cohort included 114 psoriasis patients (72 men and 42 women) with a mean ± SD follow-up duration of 28.2 ± 17.7 months, during which 24 patients developed PsA (9.7 per 100 patient-years [95% confidence interval (95% CI) 6.2-14.5]). Patients with structural entheseal lesions were at higher risk of developing PsA compared to patients without such lesions (21.4 per 100 patient-years [95% CI 12.5-34.3]; hazard ratio [HR] 5.10 [95% CI 1.53-16.99], P = 0.008). With respect to vBMD, a 1-SD increase in entheseal, but not intraarticular, vBMD was associated with an ~30% reduced risk of progression to PsA. Especially, higher cortical vBMD at entheseal segments was associated with a lower risk of developing PsA (HR 0.32 per 1 SD [95% CI 0.14-0.71]), and the association remained robust after multiple imputation of missing data (HR 0.64 [95% CI 0.42-0.98])., Conclusion: The presence of structural entheseal lesions as well as low cortical vBMD at entheseal segments are associated with an increased risk of developing PsA in patients with psoriasis., (© 2021 The Authors. Arthritis & Rheumatology published by Wiley Periodicals, Inc. on behalf of American College of Rheumatology.)

Diffusible iodine-based contrast-enhanced computed tomography (diceCT) is progressively used in clinical and morphological research to study developmental anatomy. Lugol's solution (Lugol) has gained interest as an effective contrast agent; however, usage is limited due to extensive soft-tissue shrinkage. The mechanism of Lugol-induced shrinkage and how to prevent it is largely unknown, hampering applications of Lugol in clinical or forensic cases where tissue shrinkage can lead to erroneous diagnostic conclusions. Shrinkage was suggested to be due to an osmotic imbalance between tissue and solution. Pilot experiments pointed to acidification of Lugol, but the relation of acidification and tissue shrinkage was not evaluated. In this study, we analyzed the relation between tissue shrinkage, osmolarity and acidification of the solution during staining. Changes in tissue volume were measured on 2D-segmented magnetic resonance and diceCT images using AMIRA software. Partial correlation and stepwise regression analysis showed that acidification of Lugol is the main cause of tissue shrinkage. To prevent acidification, we developed a buffered Lugol's solution (B-Lugol) and showed that stabilizing its pH almost completely prevented shrinkage without affecting staining. Changing from Lugol to B-Lugol is a major improvement for clinical and morphological research and only requires a minor adaptation of the staining protocol., (© 2021. The Author(s).)

Most of the objects targeted for X-ray examination are composed of soft-tissue and bone. We aimed to develop an algorithm for generating X-ray images which can give quantitative information of soft-tissue and bone using an energy-resolving photon-counting type imaging detector. We used polychromatic X-rays for analysis in which both the beam hardening effect and detector response were properly corrected and then succeeded in virtually treating the amount of measured X-ray attenuation as if it were measured using monochromatic X-rays., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Mass spectrometry imaging (MSI) is an emerging technology that holds potential for improving, biomarker discovery, metabolomics research, pharmaceutical applications and clinical diagnosis. Despite many solutions being developed, the large data size and high dimensional nature of MSI, especially 3D datasets, still pose computational and memory complexities that hinder accurate identification of biologically relevant molecular patterns. Moreover, the subjectivity in the selection of parameters for conventional pre-processing approaches can lead to bias. Therefore, we assess if a probabilistic generative model based on a fully connected variational autoencoder can be used for unsupervised analysis and peak learning of MSI data to uncover hidden structures. The resulting msiPL method learns and visualizes the underlying non-linear spectral manifold, revealing biologically relevant clusters of tissue anatomy in a mouse kidney and tumor heterogeneity in human prostatectomy tissue, colorectal carcinoma, and glioblastoma mouse model, with identification of underlying m/z peaks. The method is applied for the analysis of MSI datasets ranging from 3.3 to 78.9 GB, without prior pre-processing and peak picking, and acquired using different mass spectrometers at different centers., (© 2021. The Author(s).)

Time-reversed ultrasonically-encoded (TRUE) optical focusing is a promising technique to realize deep-tissue optical focusing by employing ultrasonic guide stars. However, the sizes of the ultrasound-induced optical focus are determined by the wavelengths of the ultrasound, which are typically tens of microns. To satisfy the need for high-resolution imaging and manipulation, iterative TRUE (iTRUE) was proposed to break this limit by triggering repeated interactions between light and ultrasound and compressing the optical focus. However, even for the best result reported to date, the resolutions along the ultrasound axial and lateral direction were merely improved by only 2-fold to 3-fold. This observation leads to doubt whether iTRUE can be effective in reducing the size of the optical focus. In this work, we address this issue by developing a physical model to investigate iTRUE in a reflection mode numerically. Our numerical results show that, under the influence of shot noises, iTRUE can reduce the optical focus to a single speckle within a finite number of iterations. This model also allows numerical investigations of iTRUE in detail. Quantitatively, based on the parameters set, we show that the optical focus can be reduced to a size of 1.6 µm and a peak-to-background ratio over 10 4 can be realized. It is also shown that iTRUE cannot significantly advance the focusing depth. We anticipate that this work can serve as useful guidance for optimizing iTRUE system for future biomedical applications, including deep-tissue optical imaging, laser surgery, and optogenetics.

Introduction: The infringement of supracrestal tissue attachment by subgingival restorative margins, extensive caries, and root fractures, can compromise the periodontal health, resulting in inflammation and loss of periodontal supporting tissues. This report describes a case of a root fracture on the upper left central incisor that was successfully treated using a conservative approach, by applying the restorative alveolar interface (RAI) management combined with tunnel technique and a subepithelial connective tissue graft (SCTG)., Case Presentation: A 24-year-old male patient presented with a provisional single-unit fixed prosthesis on his upper left central incisor, in function for 4 years, with the chief complaint of prosthesis discoloration. After clinical and radiographic examination, a diagnosis of root fracture was established. Following the removal of the provisional prosthesis, a full-thickness flap was elevated creating a tunnel. The elimination of the fracture line/angle, root recontouring, and planning was then performed with the aid of a conical long diamond bur and periodontal curets. Additionally, an SCTG was placed buccally into the tunnel. The final zirconia layered with E-max crown was placed 6 months after surgery. At 12- and 24-month follow-up, the periodontal tissues presented healthy aspect, no bleeding on probing, and a 4-mm probing depth., Conclusions: Surgical repositioning of the restorative margin can be an alternative and conservative treatment approach to compromised teeth with subgingival fracture line/angle. However, case selection should be carefully considered and restorability assessed as limitations might apply., (© 2020 American Academy of Periodontology.)

Background: Nowadays, due to the esthetic and social demands of patients, conventional staged protocols seem to be increasingly replaced by faster, one-step protocols. The purpose of the present systematic review is to assess the peri-implant soft tissue changes after immediate implant placement and provisionalization (IIPP) comparing patients treated with or without a sub-epithelial connective tissue graft (SCTG) when replacing a single tooth in the esthetic region., Methods: The present systematic review was written following the PRISMA checklist. Immediate implants placed with a connective tissue graft and without one were compared. The researched primary outcomes were the mid-buccal mucosa level (MBML) facial soft tissue thickness (FSTT) and marginal bone loss (MBL). The weighted mean differences (WMD) were estimated for all three outcomes., Results: The change in the mid-buccal mucosa level in the intervention group was significantly higher (WMD 0.54; 95% CI 0.33-0.75), with no indication of heterogeneity (I 2 = 16%). The facial soft tissue thickness increased significantly in the intervention group (WMD 0.79; 95% CI 0.37-1.22). The marginal bone loss was significantly higher in the control group (WMD 0.13; 95% CI 0.07-0.18), with no indication of heterogeneity (I 2 = 0%)., Conclusions: The results of the meta-analyses showed a statistically significant reduced change of the marginal bone loss and vestibular recession, as well as higher soft tissue thickness, when a graft was used. The included studies had a short observation time; therefore, studies with longer follow-ups are needed to confirm these findings., (© 2021. The Author(s).)

Background: Carpal tunnel syndrome patients demonstrate diminished motion of the median nerve and fibrotic changes in the subsynovial connective tissue within the carpal tunnel. Currently, there are few prognostic factors to help predict the outcome of commonly performed treatments including surgical carpal tunnel release and corticosteroid injections. This study aimed to non-invasively assess the changes in the dynamic response of the subsynovial tissue relative to tendon motion after the intervention and to correlate this with disease severity., Methods: A total of 145 patients with carpal tunnel syndrome were recruited into this study. Clinical and demographic data, electrophysiological severity and dynamic ultrasound images were collected before and after treatment, either by injection or surgery. The relative motion of the subsynovial tissue with the underlying middle finger flexor digitorum superficialis tendon was measured using a speckle tracking algorithm and was expressed as a shear index (SI). Baseline and follow-up data, the association between change in SI and severity, and the role of treatment modality were analyzed and statistically compared., Findings: Overall, there was a significant increase (more relative motion) after treatment in the mean shear index from 79.9% (±15.4% SD) to 82.9% (±14.8% SD) (p = 0.03). Secondary analyses showed that this change was mostly present in those with mild disease severity undergoing surgery (p = 0.01)., Interpretation: This study shows that the relative subsynovial tissue movement increases in patients after intervention. The present study lays a foundation for future studies to non-invasively assess the role of carpal tunnel dynamics in response to treatment., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Purpose: Magnetic resonance imaging can detect soft- and hard-tissue abnormalities and has become the primary imaging modality for temporomandibular joints. However, few studies have quantitatively evaluated rheumatoid arthritis (RA) in temporomandibular joints using diffusion-weighted imaging. The purpose of this study was to assess the apparent diffusion coefficient (ADC) values of the inflammatory connective tissue around the mandibular condyle in RA., Methods: This was a retrospective cohort study. We analyzed the magnetic resonance imaging studies of patients with suspected temporomandibular joint disorders performed between April 2008 and August 2020. The predictor variable was disease status (RA-y/n). The primary outcome variable was the mean of ADC values of the connective tissue around the mandibular condyle. The other variables were age and sex. Furthermore, the ADC values were compared between the 2 groups. Data were analyzed using a Mann-Whitney U test, Spearman's correlation coefficient, and a receiver operating characteristic curve. P < .05 was considered to indicate statistical significance., Results: In total, 35 patients (18 normal patients and 17 patients with RA) were included. The mean ADC values were 1.26 ± 0.11 × 10 -3  mm 2 /s and 1.60 ± 0.19 × 10 -3  mm 2 /s in the control and RA groups, respectively (P < .001). Receiver operating characteristic analysis revealed that a cutoff of 1.37 for ADC values for RA provided an accuracy of 0.86. The sensitivity and specificity of ADC values were 0.94 and 0.83, respectively., Conclusions: ADC values of the inflammatory connective tissue around the mandibular condyle in RA were significantly higher in the RA group than those in the control group. This parameter might be useful for the quantitative evaluation of RA., (Copyright © 2021 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Connective tissue grafting has a beneficial effect on the peri-implant mucosa, but the effect of grafting the buccal mucosa on buccal bone thickness (BBT) has not been investigated, although BBT is proposed to be a key factor for the soft-tissue contour. The aim of this trial was to assess the outcome of a connective tissue graft (CTG) in the esthetic zone of single immediate implants on the change of BBT according to cone beam computed tomography (CBCT) scan analysis., Methods: In a 1-year randomized controlled trial, 60 patients received an immediately placed implant and provisionalization, either combined with CTG (test group) or without CTG (control group). CBCTs were taken preoperatively (T pre ) and 1 year after definitive restoration (T 2 ). Any change in BBT was assessed at different implant levels. Additionally, the change in mid-buccal mucosal level (MBML) and approximal marginal bone level were assessed., Results: Fifty-five patients were available for statistical analysis (test group, n = 28; control group, n = 27). At T 2 , the average change in BBT was significantly larger in the test group (-0.84 ± 0.61 mm) than in the control group (-0.46 ± 0.54 mm, P = 0.02). A MBML gain of 0.07 ± 0.85 mm in the test and a MBML loss -0.52 ± 1.16 mm in the control group was observed at T 2 . Average loss of marginal bone was 0.05 ± 0.33 mm and 0.01 ± 0.38 mm, respectively., Conclusions: The application of CTG in the esthetic zone of immediately placed and provisionalized implants is accompanied with more loss of BBT, but at the same time better maintains the mid-buccal mucosal level., (© 2020 The Authors. Journal of Periodontology published by Wiley Periodicals, Inc. on behalf of American Academy of Periodontology.)

Aim: To describe the application of power Doppler Ultrasonography (US) for evaluating blood flow at implant and palatal donor sites following soft tissue augmentation with the connective tissue graft (CTG)., Materials and Methods: Five patients exhibiting a peri-implant soft tissue dehiscence received treatment with a coronally advanced flap and corresponding CTG. Power Doppler US was used for assessing blood volume at baseline, 1 week, 1 month, 6 months and 12 months post-surgery for assessing blood-flow dynamics at the implant and palatal donor sites. The speed-weighted and power-weighted colour pixel density (CPPD) were computed from colour velocity (CV) and colour power (CP), respectively., Results: A mean increase in CV of 199.25% was observed at the midfacial region of the implant sites after 1 week compared to baseline. CV and CP were increased in all sites at 1 week and 1 month. At 6 and 12 months, the mean CV appeared lower than baseline at the implant sites. CCPD was increased at the palatal donor sites and at the great palatine foramen areas at the 1-week and 1-month post-operative evaluations., Conclusions: Power Doppler US is a non-invasive and valuable tool for estimating tissue perfusion and CPPD variation during different phases of intra-oral soft tissue graft healing., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Innate lymphoid cells (ILCs) emerge in the last few years as important regulators of immune responses and biological processes. Although ILCs are mainly known as tissue-resident cells, their precise localization and interactions with the microenvironment are still unclear. Here we combine a multiplexed immunofluorescence technique and a customized computational, open-source analysis pipeline to unambiguously identify CD127 + ILCs in situ and characterize these cells and their microenvironments. Moreover, we reveal the transcription factor IRF4 as a marker for tonsillar ILC3, and identify conserved stromal landmarks characteristic for ILC localization. We also show that CD127 + ILCs share tissue niches with plasma cells in the tonsil. Our works thus provide a platform for multiparametric histological analysis of ILCs to improve our understanding of ILC biology.

Background: To investigate the influence of soft-tissue volume grafting employing autogenous connective tissue graft (CTG) simultaneous to implant placement on peri-implant tissue health and stability., Material and Methods: This cross-sectional observational study enrolled 19 patients (n = 29 implants) having dental implants placed with simultaneous soft-tissue volume grafting using CTG (test), and 36 selected controls (n = 55 implants) matched for age and years in function, who underwent conventional implant therapy (i.e., without soft-tissue volume grafting). Clinical outcomes (i.e., plaque index (PI), bleeding on probing (BOP), probing depth (PD), and mucosal recession (MR)) and frequency of peri-implant diseases were evaluated in both groups after a mean follow-up period of 6.15 ± 4.63 years., Results: Significant differences between test and control groups at the patient level were noted for median BOP (0.0 vs. 25.0%; p = 0.023) and PD scores (2.33 vs. 2.83 mm; p = 0.001), respectively. The prevalence of peri-implant mucositis and peri-implantitis amounted to 42.1% and 5.3% in the test and to 52.8% and 13.9% in the control group, respectively., Conclusion: Simultaneous soft-tissue grafting using CTG had a beneficial effect on the maintenance of peri-implant health.

Background/purpose: Computer-assisted tissue imaging and analytical techniques were used to clarify the histomorphological structure of hepatic connective tissue as a practical guide for surgeons., Methods: Approximately 5000 histological slides were prepared from liver specimens of five autopsied patients. Three-dimensional (3D) reconstruction was performed and subjected to computer imaging analysis. Scanning electron microscopy was also performed on the liver specimens., Results: The 3D reconstructed images revealed the running form of the vasculature and the relationship between the hepatic lobule and connective tissue. The hepatic capsule or portal pedicle was consistently located at the periphery of the hepatic lobules. An artificial intelligence random forest approach clearly segmented hepatic cells, type I collagen (CF), type III collagen (RF), and other cells. The hepatic lobule, portal region, and hepatic capsule were significantly distinguished based on CF and RF occupancy. The capsule directly covering the liver lobule with an RF concentration up to 87% was provisionally named the proper hepatic capsule. The existence of a proper hepatic ligament with distinct occupation rates of CF and RF was also suggested., Conclusions: The identified proper hepatic capsule and ligament can be important markers for demarcating the dissecting layer during surgical procedures., (© 2020 The Authors. Journal of Hepato-Biliary-Pancreatic Sciences published by John Wiley & Sons Australia, Ltd on behalf of Japanese Society of Hepato-Biliary-Pancreatic Surgery.)

Background: Greater Saphenous Vein (GSV) courses within saphenous compartment, an adipose-filled space bound by fasciae provides structural support. Ultrasound Shear-Wave Elastography (SWE) provides objective and quantitative data on tissue shear elasticity modulus., Objective: This study aims to analyze possible associations between early stage GSV insufficiency and saphenous intracompartmental SWE measurements., Methods: Two-hundred consecutive patients, ages 22 to 81 (mean=44.3) years, with venous insufficiency symptoms underwent Doppler and SWE examinations. Patients had no visible or palpable sign of venous disease or had telangiectasia and reticular veins only. Analyses regarding patient age, gender, presence of venous insufficiency of GSV proper and intracompartmental connective tissue elasticity were performed., Results: Ninety-six patients had Doppler evidence for either bilateral or unilateral insufficiency of GSV proper at mid-thigh level. Intracompartmental elasticity of patients with venous insufficiency (mean=4.36±2.24 kilopascals; range 1.55 to 10.44 kPa) did not differ significantly from those with normal veins (mean=4.82±2.61 kPa; range 2.20 to 12.65 kPa) (p=0.231). No threshold for predicting the presence of venous insufficiency could be determined. Neither were there any correlations between age, gender and intracompartmental elasticity. In patients with unilateral insufficiency, however, elastography values around insufficient veins were significantly lower compared to contralateral normal GSV (p<0.001)., Conclusion: Many intrinsic and patient factors affect intracompartmental connective tissue elastography measurements; thus, cut-off values obtained from specific populations have limited generalizability. Nevertheless, statistically significant intrapatient differences of intracompartmental elasticity among diseased and normal saphenous veins indicate that lack of elastic support from surrounding connective tissues contributes to venous insufficiency in early stages., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Purpose of Review: Despite immunology and translational therapeutics advances in inflammatory arthritis over the past two decades, the enthesis, which is the epicentric of the spondyloarthritis family pathological process, retains many mysteries because of tissue inaccessibility that hampers direct immune study. As entheses are subject to almost continuous mechanical stress and spondyloarthritis is linked to microdamage or injury and joint stress, it is cardinal to understand the physiological changes occurring within the entheses not only to be able to differentiate disease from health but also to understand the transition normal physiology break down and its merges into spondyloarthritis-related disease., Recent Findings: Imaging has played a major role in understanding the enthesis in human. Remarkable insights from enthesis functioning and microdamage in normal and with ageing including those linked to body mass index is emerging. The impact of mechanical stress and degenerative conditions on the development of the secondary entheseal vascular changes is not understood. Of note, ultrasound studies in psoriasis have shown higher power Doppler changes compared to controls pointing towards a role for vascular changes in the development of enthesitis in psoriatic arthritis., Summary: The literature pertaining to normal entheses changes with age, microdamage and vascular changes in health is providing a roadmap for understanding of the enthesis and its potential role in evolution of spondyloarthritis including psoriatic arthritis.

The aim in this study was to evaluate the influence of skeletal class, facial type, and sex on soft tissue thickness (STT) of the craniofacial midline in a Brazilian subpopulation. Thus, 121 cone beam computed tomography (CBCT) scans (54 males and 67 females, age 21 to 40 yrs) composed the study sample. Patients were classified according to skeletal class (class I, II, and III) and facial type (brachycephalic, mesocephalic, and dolichocephalic), and STT was measured (mm) in 10 landmarks in the craniofacial midline for each CBCT scan. Multivariate analysis of covariance evaluated facial STT with regard to multiple independent variables (sex, age - covariate, facial type, and skeletal class). TEM and rTEM assessed the intra-examiner agreement. STT was significantly greater in males than in females for all regions measured (p < 0.05), except for the pogonion-pogonion' landmark (p>0.05). In general, class III individuals had significantly thicker soft tissue in the maxilla - subspinale-subnasale', prosthion-labrale superius', and incision-stomion' regions, while class II subjects had thicker soft tissue in the infradentale-labrale inferius' mandibular landmark (p < 0.05). Regarding facial type, dolichocephalic individuals showed significantly thicker soft tissue in the supramentale-supramentale' mandibular landmark, whereas brachycephalic subjects had thicker soft tissue in maxillary regions - prosthion-labrale superius' and incision-stomion' (p < 0.05). rTEM values were below 5% for most landmarks, and all TEM values were below 1 mm. Skeletal class and facial type influence STT, showing a soft tissue compensation, with deeper soft tissue in areas with lower skeletal development, and/or where bone is positioned more posteriorly., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Introduction: The thickness of connective tissue has been shown to be associated with pain (Stecco et al., 2014). However, the relationship between fascial thickness and gliding remains unclear. In addition, the influence between gliding and the motion rhythm and limb position isn't clear., Method: A therapist moved patient's lower leg at one of two constant rhythms (40 or 60bpm). Gliding of both the vastus lateralis (VL) muscle and subcutaneous (SC) tissue were recorded during knee motion using ultrasonography. Particle image velocimetry analysis software was adapted to create the flow velocity from echo imaging. Gliding was calculated using a coefficient of correlation from each flow velocity. Myofascial thickness and SC were measured using Image-J. The ratios of the loose connective tissue (LCT) and dense connective tissue (DCT) thickness to the total myofascial thickness were calculated. Repeated-measures two-way ANOVA was used to compare the two motion rhythms and three positions, with stepwise multiple regression analysis to analyze the predictors that influenced the gliding coefficient at each rhythm., Results: Repeated-measures two-way ANOVA showed that the effect of rhythm was statistically significant, but the effect of position was not. At a 40 bpm rhythm, stepwise multiple regression analysis selected SC thickness and DCT thickness as significant factors, while at a 60 bpm rhythm, SC thickness and DCT ratio were selected., Conclusion: This study revealed that increased thickness of DCT of the myofascia and SC resulted in decreased gliding between the VL and SC, demonstrating that gliding is related to fascial thickness. Motion rhythm influences gliding between tissues., Competing Interests: Declaration of competing interest None., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Previous studies on knee biomechanics have mainly focused on the joint structure itself, largely neglecting the material properties of the muscles and connective tissues around the knee joint. Therefore, this study was purposed to conduct a systematic in vivo examination of the material properties of muscles, tendons, and ligaments, and investigated the respective influences of gender and age on the material properties. The participants were 50 healthy males and females within the following four age groups: 21-30 years, 31-40 years, 41-50 years, and above 51 years. The Young's moduli of the muscles, tendons, and ligaments around the knee joint were measured by shear wave elastography (SWE). Analysis of the Young's modulus results showed that excellent repeatability could be achieved by using SWE. For muscles, the intraclass correlation coefficient (ICC) and 95% confidence interval (CI) ranged between 0.952 and 0.987, and 0.923 and 0.992, respectively. The ICC ranged from 0.920 to 0.941, and the 95% CI was between 0.872 and 0.969 for tendons and ligaments. Additionally, the Young's moduli of the muscles, tendons, and ligaments of males were greater than those of females. With the exception for medial patellar retinaculum (MPR), the Young's moduli of other observed tissues decreased with age for both males and females, indicating that age has a significant impact on the Young's moduli of muscles, tendons, and ligaments. Hence, SWE is a reliable and repeatable technique that can be used to assess the Young's moduli of the muscles, tendons, and ligaments around the knee joint. Furthermore, gender and age affects the material properties. The results of this study provide an in vivo database of the material properties of muscles and connective tissues, and thus may prove useful for the prevention and treatment of knee joint injuries and diseases., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The aim of this study is to review and discuss the literature on the utilization of magnetic resonance imaging (MRI) in investigating the structure and feasible function of the myodural bridge complex (MDBC) with relevant muscles, which will be useful to understand the function of the MDB. The myodural bridge (MDB) is a soft tissue connective bridge that provides a fascial continuity between the musculature/ligament and cervical spinal dura mater (SDM) in the suboccipital areas. All of these involved structures are referred to as the MDBC. It would transfer tensile forces effectively from involved suboccipital muscles/ligament to SDM during head movement. Despite present achievements, its anatomic and functional role is still unclear. MRI enables not only in vivo visualization of ligaments, musculature and spinal dura with conventional T 1 W, T 2 W and PDW imaging, but also functional evaluation of MDBC with relevant muscles, such as muscles' fatty infiltration, cross-sectional area changes and injuries. Though some functional MRI techniques have not been used for the MDBC with relevant muscles now, these techniques have great potential to better understand function of MDBC including its suspected clinical role. MRI is likely the most powerful tool to study MDBC and relevant muscles with only limited exploration so far., Competing Interests: The authors have no conflict of interest.

Excursion of the median nerve and the surrounding subsynovial connective tissue (SSCT) is diminished in patients with carpal tunnel syndrome (CTS). This study sought to determine if SSCT excursion could be utilized to predict surgical outcome. Idiopathic CTS patients were reviewed with ultrasound and electrodiagnostic tests at baseline. A speckle tracking algorithm was used to determine SSCT relative to tendon motion (shear index). Analysis of variance tests were used to compare SSCT motion with disease severity at baseline. Adjusted linear regressions were used to test the association with patient-reported outcome. A total of 90 CTS patients were analyzed and found to have an average shear index of 79% (95% confidence interval: 76.3%-81.6%). SSCT motion was lower in CTS patients with increasing electrophysiological severity (p = 0.0475). There was no significant association of pre-operative SSCT motion with symptomatic improvement (p = 0.268). Overall, SSCT motion is decreased in CTS patients, but exhibits limited correlation with clinical severity., Competing Interests: Declaration of Competing Interest None, (Copyright © 2020 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.)

Ultrasonography is a valuable tool that can be used in many capacities to evaluate and treat pediatric orthopaedic patient. It has the capability to depict bone, cartilaginous and soft-tissue structures, and provide dynamic information. This technique can be readily applied to a wide range of pediatric conditions, including developmental dysplasia of the hip, congenital limb deficiencies, fracture management, joint effusions, and many other musculoskeletal pathologies. There are many benefits of implementing ultrasonography as a regular tool. It is readily accessible at most centers, and information can be quickly obtained in a minimally invasive way, which limits the need for radiation exposure. Ultrasonography is a safe and reliable tool that pediatric orthopaedic surgeons can incorporate into the diagnosis and management of a broad spectrum of pathology.

Aims: To evaluate the hard and soft tissue alterations of immediately placed and provisionalized implants with or without connective tissue graft (CTG)., Materials and Methods: Single unsalvageable maxillary incisors were replaced with immediately placed and provisionalized implants in 42 participants. The patients were randomly assigned to receive simultaneous CTG (test group) and not receive CTG (control group). Digital impression and cone-beam computed tomography images were obtained before extraction and after 6 months. Mid-facial gingival margin migrations, soft tissue contour changes and hard tissue remodelling were analysed and compared between the two groups using three-dimensional superimposition method., Results: Forty participants completed the study. The test group showed significantly less buccal tissue collapse in the area 2-5 mm apical to the gingival margin. In both groups, the mid-facial gingival margin migrated in an apico-palatal direction and the socket void, except for a triangular space in the bucco-coronal region, demonstrated radiographic new bone formation without statistically significant differences., Conclusions: The CTG used with immediate implant placement and provisionalization could compensate for the facial tissue collapse, but it did not benefit maintenance of the mid-facial gingival margin position during the 6-month follow-up. New bone formation observed radiographically can be expected in most areas of the socket void, regardless of CTG use (ChiCTR-1900028494)., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Cystic fibrosis is characterized by lung dysfunction involving mucus hypersecretion, bacterial infections, and inflammatory response. Inflammation triggers pro-fibrotic signals that compromise lung structure and function. At present, several in vitro cystic fibrosis models have been developed to study epithelial dysfunction but none of these focuses on stromal alterations. Here we show a new cystic fibrosis 3D stromal lung model made up of primary fibroblasts embedded in their own extracellular matrix and investigate its morphological and transcriptomic features. Cystic fibrosis fibroblasts showed a high proliferation rate and produced an abundant and chaotic matrix with increased protein content and elastic modulus. More interesting, they had enhanced pro-fibrotic markers and genes involved in epithelial function and inflammatory response. In conclusion, our study reveals that cystic fibrosis fibroblasts maintain in vitro an activated pro-fibrotic state. This abnormality may play in vivo a role in the modulation of epithelial and inflammatory cell behavior and lung remodeling. We argue that the proposed bioengineered model may provide new insights on epithelial/stromal/inflammatory cells crosstalk in cystic fibrosis, paving the way for novel therapeutic strategies.

Vertebral endplate bone marrow lesions, visualized on magnetic resonance imaging (MRI) as Modic changes (MC), are associated with chronic low back pain (cLBP). Since guidelines recommend against routine spinal MRI for cLBP in primary care, MC may be underdiagnosed. Serum biomarkers for MC would allow early diagnosis, inform clinical care decisions, and supplement treatment monitoring. We aimed to discover biomarkers in the blood serum that correlate with MC pathophysiological processes. For this single-site cross-sectional study, we recruited 54 subjects with 38 cLBP patients and 16 volunteers without a history of LBP. All subjects completed an Oswestry Disability Index (ODI) questionnaire and 10-cm Visual Analog Score (VAS) for LBP (VASback) and leg pain. Lumbar T1-weighted and fat-saturated T2-weighted MRI were acquired at 3T and used for MC classification in each endplate. Blood serum was collected on the day of MRI. Biomarkers related to disc resorption and bone marrow fibrosis were analyzed with enzyme-linked immune-absorbent assays. The concentration of biomarkers between no MC and any type of MC (AnyMC), MC1, and MC2 were compared. The Area Under the Curve (AUC) of the Receiver Operating Characteristics were calculated for each biomarker and for bivariable biomarker models. We found that biomarkers related to type III and type IV collagen degradation and formation tended to correlate with the presence of MC ( p = 0.060-0.088). The bivariable model with the highest AUC was PRO-C3 + C4M and had a moderate diagnostic value for AnyMC in cLBP patients (AUC = 0.73, specificity = 78.9%, sensitivity = 73.7%). In conclusion, serum biomarkers related to the formation and degradation of type III and type IV collagen, which are key molecules in bone marrow fibrosis, correlated with MC presence. Bone marrow fibrosis may be an important pathophysiological process in MC that should be targeted in larger biomarker and treatment studies., Competing Interests: The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

Objective: Measuring soft tissue thickness after mucogingival surgery has traditionally been performed by means of a calibrated transgingival probe. The main aim of this study was to apply a non-invasive technique based on digital images formatted as Standard Tessellation Language (STL) files to quantify soft tissue volume after connective tissue grafting., Clinical Innovation Report: Ten patients who presented Cairo Class I gingival recession were selected for connective tissue grafting using the tunnel technique. In all patients, the initial position of the gingiva and quantity of keratinized tissue were recorded, and gingival recession was scanned with an intra-oral scanner. Six months after surgery, the same intra-oral parameters were recorded and compared with the initial registers using digital volumetric analysis software., Results: Complete root coverage was obtained in most patients (90%), mean coverage being of 2.70 mm with a mean increase in volume of 115.49 mm 3 in the treated areas. No pattern was identified that indicated a statistically significant relation between gingival recession and coverage volume in mm 3 ., Conclusions: Digital processing of pre- and post-treatment images makes it possible to measure the volume of tissue gained after tissue graft surgery simply and non-invasively. The technique is an objective and reproducible method for measuring soft tissue thickness., (© 2020 The Authors. Food Science & Nutrition published by Wiley Periodicals, Inc.)

Background: Non-inflammatory thickening of the subsynovial connective tissue is a common histological finding in carpal tunnel syndrome. This subsynovial connective tissue thickening may precede changes in electrodiagnostic testing. Therefore, measuring subsynovial connective tissue thickness may help in detecting early changes in carpal tunnel syndrome., Methods: To provide an overview of subsynovial connective tissue thickness characteristics in subjects with and without carpal tunnel syndrome, a systematic review of articles, assessing human subsynovial connective tissue, was performed using MEDLINE, CENTRAL and EMBASE., Findings: Seven studies were included for qualitative analysis. Measurements were done ex vivo (laser (n = 3), photographic (n = 1), micrometric (n = 1)) and in vivo (ultrasound (n = 3)). All four case-control studies showed a significant difference in subsynovial connective tissue thickness between subjects with and without carpal tunnel syndrome. One study showed good correlation between ultrasound and anatomical measurements. No correlation was found between subsynovial connective tissue thickness and symptom duration, electrodiagnostic changes, age and sex., Interpretation: Subsynovial connective tissue thickness may be a valuable aid in diagnosing carpal tunnel syndrome. No factors influencing subsynovial connective tissue thickness are identified, although they are not well investigated., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. The authors declare no conflict of interest. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Aim: To assess mid-term clinical, radiographic and profilometric outcomes at implant sites, previously grafted with a volume-stable collagen matrix (VCMX) or an autogenous subepithelial connective tissue graft (SCTG)., Methods: VCMX or SCTG were randomly applied to single implant sites in 20 patients. Following abutment connection and insertion of final reconstructions (baseline), patients were re-examined at 6 months (6M), at 1 year (FU-1) and at 3 years (FU-3). Measurements included the following: clinical data, radiographic measurement of first bone to implant contact (fBIC), soft tissue thickness and volumetric outcomes. Non-parametric tests and estimates were applied for the statistical analysis., Results: The median buccal mucosal thickness increased by 0.5 mm (Q1: -0.5; Q3: 1.25) (VCMX) (p = .281) and by 0.8 mm (Q1: 0.0; Q3: 2.5) (SCTG) (p = .047) between BL and FU-3 (intergroup p = .303). The profilometric changes of the buccal soft tissues demonstrated a median decrease between BL and FU-3 of -0.2 mm (Q1: -0.5; Q3: -0.1) (p = .039) for VCMX and a decrease of -0.1 mm (Q1: -0.8; Q3: 0.1) (p = .020) for SCTG, respectively (intergroup p = .596). Peri-implant soft tissues and bone levels remained healthy throughout the entire study period. PROMs did not show any significant differences between the groups nor significant changes over time., Conclusion: Minimal changes of the peri-implant tissue contour as well as of the soft tissue thickness were observed at implant sites previously grafted with VCMX or SCTG., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Fibro-adipose vascular anomaly (FAVA) is a rare and recently described complex vascular malformation. The clinical and imaging features and morphology can be confusing and often overlap with features of other vascular malformations and tumors., Objective: To present the imaging characterization of FAVA in association with clinical features., Materials and Methods: We retrospectively evaluated clinical and imaging (MRI, sonography and venography) findings in FAVA. We documented the clinical presentation, lesion morphology, imaging characteristics, tissue distribution, pattern of contrast enhancement and vascular characteristics., Results: Thirty-eight people (31 female, 7 male) ages 1-30 years (mean 12 years) were diagnosed with FAVA based on clinical findings combined with imaging or histopathological findings (n=17). Most lesions were in the lower extremity (n=36). Three patterns were noticed: focal, focal infiltrative and diffuse., Conclusion: Fibro-adipose vascular anomaly, a rare and complex vascular malformation, has distinct clinical and imaging features that a radiologist should be familiar with to avoid delay in diagnosis and to direct appropriate management.

Purpose: The connective tissue between suboccipital muscles and the cervical spinal dura mater (SDM) is known as the myodural bridge (MDB). However, the adjacent relationship of the different connective tissue fibers that form the MDB remains unclear. This information will be highly useful in exploring the function of the MDB., Methods: The adjacent relationship of different connective tissue fibers of MDB was demonstrated based upon three-dimensional visualization model, P45 plastinated slices and histological sections of human MDB., Results: We found that the MDB originating from the rectus capitis posterior minor muscle (RCPmi), rectus capitis posterior major muscle (RCPma) and obliquus capitis inferior muscle (OCI) in the suboccipital region coexists. Part of the MDB fibers originate from the ventral aspect of the RCPmi and, together with that from the cranial segment of the RCPma, pass through the posterior atlanto-occipital interspace (PAOiS) and enter into the posterior aspect of the upper cervical SDM. Also, part of the MDB fibers originate from the dorsal aspect of the RCPmi, the ventral aspect of the caudal segment of the RCPma, and the ventral aspect of the medial segment of the OCI, enter the central part of the posterior atlanto-axial interspace (PAAiS) and fuse with the vertebral dura ligament (VDL), which connects with the cervical SDM., Conclusions: Our findings prove that the MDB exists as a complex structure which we termed the 'myodural bridge complex' (MDBC). In the process of head movement, tensile forces could be transferred possibly and effectively by means of the MDBC. The concept of MDBC will be beneficial in the overall exploration of the function of the MDB.

Combined ultrasound and photoacoustic imaging systems are being developed for biomedical and clinical applications. One common probe configuration is to use a linear transducer array with external light delivery to produce coregistered ultrasound and photoacoustic images. The diagnostic capability of these systems is dependent on the effectiveness of light delivery to the imaging target. We use Monte Carlo modeling to investigate the optimal design geometry of an integrated probe. Simulations are conducted with multiple tissue compositions and wavelengths. The effect of a skin layer with the thickness of a mouse or a human is also considered. The model was validated using a tissue-mimicking gelatin phantom and corresponding Monte Carlo simulations. The optimal illumination angle is shallower with human skin thickness, whereas intermediate angles are ideal with mouse skin thickness. The effect of skin thickness explains differences in the results of prior work. The simulations also indicate that even with identical hardware and imaging parameters, light delivery will be up to 3  ×   smaller in humans than in mice, due to the increased scattering from thicker skin. Our findings have clear implications for the many researchers using mice to test and develop imaging methods for clinical translation.

Sialadenoma papilliferum is a benign salivary tumour which rarely occurs in the bronchial tree. Up to now, only four cases of pulmonary papillary sialadenoma have been reported in the literature. We discuss the case of a male patient with an accidental finding of a middle lobe nodule. The patient underwent a minimally invasive anatomical resection of the lobe to remove the lesion; the postoperative course was regular, and he was healthy at the last follow-up.

Background: Morbidity following pancreaticoduodenectomy (PD) has been reported to remain high. This study sought to measure the peak Hounsfield units (HUs) of visceral attenuation in patients undergoing PD and to assess the quality of adipocytes by comparing these measurements with perioperative factors., Methods: Patients undergoing PD were retrospectively identified (n = 108). Abdominal perimeter, subcutaneous fat area (SFA), visceral fat area (VFA), and peak HU of the VFA were measured. Logistic regression analysis was used to identify independent predictors of postoperative pancreatic fistula (POPF) or complications. Histopathological examination was performed for qualitative diagnosis of the stromal tissue., Results: The overall rate of POPF was 16%, and severe complications occurred in 23% of the cases. A criterion for peak HU of the VFA only independently predicted POPF (p = 0.007) in the multivariate analysis. A criterion for peak HU of the VFA (p = 0.015) was associated with an increased rate of postoperative severe complications in the univariate analysis. The peak HU of the VFA was significantly correlated with abdominal perimeter (p < 0.001) and VFA (p < 0.001). The peak HU of the VFA was significantly correlated with adipocyte diameter (p < 0.001) and the ratio of stromal connective tissue area around the adipocytes (p < 0.001)., Conclusion: The peak HU of the VFA was an independent factor contributing to severe complications, including POPF after PD. It reflects the amount of stromal connective tissue around the adipocytes., (© 2020 S. Karger AG, Basel.)

MRI is an invaluable diagnostic tool in the investigation and management of patients with pathology of the head and neck. However, numerous technical challenges exist, owing to a combination of fine anatomical detail, complex geometry (that is subject to frequent motion) and susceptibility effects from both endogenous structures and exogenous implants. Over recent years, there have been rapid developments in several aspects of head and neck imaging including higher resolution, isotropic 3D sequences, diffusion-weighted and diffusion-tensor imaging as well as permeability and perfusion imaging. These have led to improvements in anatomic, dynamic and functional imaging. Further developments using contrast-enhanced 3D FLAIR for the delineation of endolymphatic structures and black bone imaging for osseous structures are opening new diagnostic avenues. Furthermore, technical advances in compressed sensing and metal artefact reduction have the capacity to improve imaging speed and quality, respectively. This review explores novel and evolving MRI sequences that can be employed to evaluate diseases of the head and neck, including the skull base.

Disorders of retinacula are frequent in acute and repetitive microtrauma of the ankle. Ultrasound (US), thanks to its spatial resolution and dynamic capabilities, is routinely used in the evaluation of the posttraumatic ankle for accurate delineation of ligaments and tendons. In addition, US can provide a depiction of normal retinacula and a detailed assessment of their pathologic changes. An accurate US assessment of ankle retinacula is helpful in choosing the proper treatment. In this pictorial essay, we briefly review the normal anatomy of ankle retinacula, describe their normal US appearance, and present a wide range of US pathologic abnormalities., (© 2019 by the American Institute of Ultrasound in Medicine.)

Aim: To present a new protocol to optimise ultrasound (US) assessment of haemophilic arthropathy., Materials and Methods: Ultrasound of haemophilic arthropathy joints was performed using three different ultrasound protocols, namely, the Toronto-Vellore Comprehensive Ultrasound (TVC-US) protocol, the Haemophilia Early Arthropathy Detection with Ultrasound (HEAD-US), and the newly developed Universal Simplified Ultrasound (US-US) protocol. Synovial hypertrophy, haemosiderin deposition, effusion, erosion, and cartilage loss were evaluated in 20 joints. The reliability and diagnostic efficiency of these protocols was compared using magnetic resonance imaging (MRI)., Results: The correlation between the TVC-US and US-US protocols for synovial hypertrophy was excellent: kappa significance (KS) was 1, but was substantial (KS=0.65) with the HEAD-US protocol. For effusion, both the TVC-US and the HEAD-US protocols had substantial correlation with the US-US protocol (KS=0.7 and 0.6 respectively). The correlation for erosion and cartilage loss was excellent between the TVC-US and the US-US with MRI (KS=1), but poor (KS=0) with the HEAD-US protocol. The US-US protocol also had good interobserver agreement (KS=1)., Conclusion: The accuracy of the US-US protocol is comparable to the TVC-US protocol and MRI and is superior to the HEAD-US protocol in the assessment of haemophilic arthropathy., (Copyright © 2019 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.)

Manual dissection and histological observation are common methods used to investigate human tissues. However, manual dissection can damage delicate structures while processing and histological observation provide limited information through cross-sectional imaging. Micro X-ray computed tomography (microCT) is an effective tool for obtaining three-dimensional information without damaging specimens. However, it shows limited efficiency in differentiating soft tissue parts. Use of contrast-enhancing agents, like phosphotungstic acid (PTA), can solve this problem by improving soft tissue contrast. We implemented microCT with PTA to investigate the human orbicularis retaining ligament (ORL), which is a delicate structure in the orbit area. In this method, harvested specimens are fixed in formalin, dehydrated in serial ethanol solutions, and stained with a PTA solution. After staining, microCT scanning, 3D reconstruction, and analysis are performed. Skin, ligaments, and muscles can be clearly visualized using this method. The specimen size and duration of staining are essential features of the method. The suitable specimen thickness was about 5-7 mm, above which the process was slowed, and the optimum duration was 5-7 days, below which an empty hole in the central area occasionally occurred. To maintain the location and direction of small pieces during cutting, sewing on the same region of each part is recommended. Furthermore, preliminary analyses of the anatomical structure are needed to correctly identify each piece. Parafilm can be used to prevent drying, but care should be taken to prevent specimen distortion. Our multidirectional observation showed that the ORL is composed of a multilayered meshwork of continuous plates, rather than thread-like fibers, as reported previously. These results suggest that microCT scanning with PTA is useful for examining specific compartments within complex structures of human tissue. It may be helpful in the analyses of cancer tissues, nerve tissues, and various organs, like the heart and liver.

What causes scattering of ultrasound from normal soft tissues such as the liver, thyroid, and prostate? Commonly, the answer is formulated around the properties of spherical scatterers, related to cellular shapes and sizes. However, an alternative view is that the closely packed cells forming the tissue parenchyma create the reference media, and the long cylindrical-shaped fluid vessels serve as the scattering sites. Under a weak scattering or Born approximation for the extracellular fluid in the vessels, and assuming an isotropic distribution of cylindrical channels across a wide range of diameters, consistent with a fractal branching pattern, some simple predictions can be made about the nature of backscatter as a function of frequency in soft tissues. Specifically, a number of plausible shapes would predict that backscatter increases as a power law of frequency, where the power law is determined by the function governing the number density of the vessels versus diameter. These results are compared with some historical models developed over the last 100 years in scattering theory and point to the need for higher spatial resolution and higher bandwidths to obtain more precise measures of the key parameters in normal tissues, and to better identify the dominant structures responsible for backscatter in everyday clinical imaging.

Objective: The purpose of this study was to analyze facial soft tissue thickness and cranial skeletal transverse widths in adolescent subjects with different body mass index (BMI) percentiles., Methods: The 80 subjects were divided into three groups according to BMI percentile: normal-weight, overweight, and obese adolescent subjects. Facial soft tissue linear and cranial skeletal transversal width measurements were performed on lateral and postero-anterior cephalometric radiographs., Results: Glabella, nasion, pogonion, and gnathion soft tissue thicknesses were significantly different among normal-weight, overweight, and obese subjects ( p  < 0.05). However, other facial soft tissue thickness parameters were not statistically significantly different among the groups ( p  > 0.05). Moreover, there were no significant differences in cranial skeletal transversal widths among groups ( p  > 0.05)., Conclusion: Nasion soft tissue thickness was thicker in overweight subjects; whereas, glabella, pogonion and gnathion soft tissue thickness was thicker in obese subjects. All measured cranial skeletal widths were similar in normal-weight, overweight, and obese subjects.

Objectives: Previous MRI studies showed that involvement of connective tissue in muscle injuries may prolong recovery times. The relevance of ultrasound assessment of connective tissue involvement as a prognostic factor is unknown. The aim was to test the hypothesis that ultrasound-detected connective tissue involvement in acute muscle injuries are related to longer recovery times., Design: Cohort study., Methods: Seventy consecutive elite athletes from the French National Institute of Sports (INSEP) sustaining an acute muscle injury showing positive findings on ultrasound at baseline were included. Ultrasound was systematically performed within 7days after the injury for the assessment of severity (grades 1-4) and type of injury in regard to the absence (M injuries) or presence (C injuries) of connective tissue involvement. The differences in the mean time needed to return to play (RTP) between the different grades and types of injury were assessed using multiple non-parametric tests., Results: When considering the overall grades independently of the type of injury (M or C), an increase in the mean time needed to RTP was observed with the increase of grades (p<0.0001). The same relationship was found when considering grades from M and C injuries separately, with higher grades of injuries exhibiting longer times needed to RTP (p<0.0001). Longer times needed to RTP were observed in athletes demonstrating C injuries in comparison to the ones exhibiting M injuries overall (p=0.002)., Conclusions: Ultrasound-detected connective tissue involvement in acute muscle injuries are related to longer times needed to RTP, especially when disruption is detected., (Copyright © 2019 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.)

Robotic surgeries in the extreme Trendelenburg position can lead to changes in the airway dimensions. We conducted a prospective, observational trial to explore the use of ultrasound to quantify these changes in the airway dimensions and identify the factors associated with it. Fifty-two American society of Anaesthesiologists physical status I-II patients between 18 and 70 years of age of either sex scheduled to undergo robot assisted urological procedures in steep Trendelenburg position were enrolled. Anterior soft tissue thickness at the level of hyoid bone and vocal cords, tongue thickness, Malampatti grading and neck circumference were measured at predefined postoperative intervals in the immediate postoperative period, at 2-, 6- and 12-h period postoperatively. Linear stepwise regression analysis was done to explore the factors associated with change in anterior tissue thickness immediately after surgery. The mean difference (95%; CI) in the anterior soft tissue thickness in the immediate postoperative period at the level of hyoid was 0.023 (0.029-0.016) cm, p < 0.001 and at level of vocal cords was - 0.012 (- 0.017 to - 0.008) cm, p < 0.001 from the baseline. There was a significant increase in tongue thickness (0.002), Mallampati score (p = 0.002) and neck circumference (p < 0.001) in immediate postoperative period. The change in anterior tissue thickness at the level of hyoid was affected by total intraoperative fluids used (r = 0.602, p < 0.001), airway trauma (r = 0.275, p = 0.002) and duration of surgery (r = 0.243, p = 0.025). Significant changes in airway dimensions after robotic surgeries in Trendelenburg position persist till 2 h in the postoperative period which warrant vigilant monitoring for any airway compromise during this period.

Purpose: Characteristic swelling has been described as a differentiating sign of pyogenic flexor tenosynovitis (PFT) but has not been validated. We conducted a retrospective study of adults with finger infections to compare radiographic parameters of soft tissue dimensions. Our hypothesis was that in patients with digit infections, radiographic soft tissue thickness measurement would differ between PFT and non-PFT infected digits., Methods: Patients with a finger infection and radiographic evaluation were identified retrospectively at a large academic medical center and divided into 2 groups: PFT (n = 31) and non-PFT infections (n = 31). We defined PFT as purulence in the tendon sheath or positive culture growth from the sheath at surgery. Non-PFT infections included all other finger infections such as abscesses and cellulitis. A total of 15 radiographic measurements were made on all included digits. Ratios and differences were calculated to characterize the pattern of swelling for each infected finger. Bivariate analysis was performed to identify potential predictor variables between the PFT and non-PFT groups. Logistic regression was performed to reduce confounding and model potential relationships., Results: Neither presence of diffuse swelling nor the shape of finger swelling distinguished PFT from non-PFT infections. All finger infections resulted in diffuse swelling. Pyogenic flexor tenosynovitis was distinguished by differential volar soft tissue thickness minus dorsal soft tissue thickness on radiographs at the proximal phalanx level (9 ± 1 mm for PFT vs 5 ± 1 mm for non-PFT). This was an independent predictor of PFT. The area under the receiver operating curve was 0.83 (95% confidence interval, 0.73-0.94). A difference between volar and dorsal soft tissue swelling of 7 mm or greater had a positive predictive value of 82% with a sensitivity of 84% and specificity of 74%. A difference of 10 mm predicted PFT infection with 76% probability (95% confidence interval, 73% to 99%)., Conclusions: Pyogenic flexor tenosynovitis may result in uniform finger swelling, but this does not appear to distinguish PFT from other finger infections. Acute PFT swelling is distinguished by differential volar versus dorsal radiographic soft tissue thickness at the level of the proximal phalanx. The term "fusiform swelling" is a misnomer for the appearance of acute PFT because the finger is not spindle-shaped., Type of Study/level of Evidence: Diagnostic IV., (Copyright © 2019 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.)

Collagen accounts for the major extracellular matrix (ECM) component in many tissues and provides mechanical support for cells. Magnetic Resonance (MR) Imaging, MR based diffusion measurements and MR Elastography (MRE) are considered sensitive to the microstructure of tissues including collagen networks of the ECM. However, little is known whether water diffusion interacts with viscoelastic properties of tissues. This study combines highfield MR based diffusion measurements, novel compact tabletop MRE and confocal microscopy in collagen networks of different cross-linking states (untreated collagen gels versus additional treatment with glutaraldehyde). The consistency of bulk rheology and MRE within a wide dynamic range is demonstrated in heparin gels, a viscoelastic standard for MRE. Additional crosslinking of collagen led to an 8-fold increased storage modulus, a 4-fold increased loss modulus and a significantly decreased power law exponent, describing multi-relaxational behavior, corresponding to a pronounced transition from viscous-soft to elastic-rigid properties. Collagen network changes were not detectable by MR based diffusion measurements and microscopy which are sensitive to the micrometer scale. The MRE-measured shear modulus is sensitive to collagen fiber interactions which take place on the intrafiber level such as fiber stiffness. The insensitivity of MR based diffusion measurements to collagen hydrogels of different cross-linking states alludes that congeneric collagen structures in connective tissues do not hinder extracellular diffusive water transport. Furthermore, the glutaraldehyde induced rigorous changes in viscoelastic properties indicate that intrafibrillar dissipation is the dominant mode of viscous dissipation in collagen-dominated connective tissue.

Aim: Radiographs (X-rays) are used for the preoperative assessment of hallux valgus (HV). Our purpose was to determine how well quantitative measurements of HV on radiographs and MRI correlate with the qualitative soft tissue and internal derangement findings on MRI., Materials and Methods: After IRB approval, 56 consecutive patients with MRI and radiographs of the foot were retrospectively reviewed. Two trained readers independently evaluated radiographs, measuring hallux valgus angle (HVA) and intermetatarsal angle (IMA). Two separate readers assessed qualitative MRI data by evaluating 21 different soft tissue and bony features. Statistical analysis included inter-reader reliability (IRR) and correlation of quantitative and qualitative findings., Results: Excellent IRR (ICC = 0.89-0.96) was observed for radiograph and MRI measurements of the hallux valgus severity. For qualitative assessments on MRI, IRR was good to excellent for all features (ICC = 0.63-0.9). No significant difference was found for HVA or IMA between normal and abnormal qualitative MRI features. No statistically significant correlation between the severity of hallux valgus and injury to hallux joints and supporting structures was found., Conclusion: Hallux valgus measurements are reliable on x-rays and MRI and qualitative findings of 1st MTP joint show good to excellent inter-reader agreement on MRI. No statistically significant correlations exist between the severity of hallux valgus and qualitative MRI findings., (Copyright © 2019 Elsevier B.V. All rights reserved.)