Precise and simple quantitation of liver steatosis by MRI in an animal model and in patients with NAFLD

International audienc

Digital Twinning remote laboratories for online practical learning, Production & Manufacturing Research

The COVID19 pandemic has demonstrated a need for remote learning and virtual learning applications such as virtual reality (VR) and tabletbased solutions. Creating complex learning scenarios by developers is highly time-consuming and can take over a year. It is also costly to employ teams of system analysts, developers, and 3D artists. There is a requirement to provide a simple method to enable lecturers to create their own content for their laboratory tutorials. Research has been undertaken into developing generic models to enable the semiautomatic creation of virtual learning tools for subjects that require practical interactions with the lab resources. In addition to the system for creating digital twins, a case study describing the creation of a virtual learning application for an electrical laboratory tutorial is presented, demonstrating the feasibility of this approach

Fuzzy algorithms: Application to adipose tissue quantification on MR images

Abstract Metabolic syndrome, which is related to abdominal obesity, is a fast growing disease in our western countries. Its presence greatly increases the risk of developing cardiovascular diseases. The accumulation of visceral adipose tissue plays a key role in the development of the metabolic syndrome. The increase of waist circumference is one of the five criteria of the metabolic syndrome diagnosis. But this increase can be due to visceral or subcutaneous adipose tissues. And these adipose tissues do not play the same rule in metabolic syndrome. The purpose of this study was to develop software for automatic and reliable quantification of visceral and subcutaneous adipose tissues, to detect patient with high risk to develop metabolic syndrome and to follow the evolution of adipose tissue repartition after treatment. A gradient echo magnetic resonance (MR) technique is used, with a TE such that fat and water are opposed in phase. The developed process is based on two fuzzy algorithms. First, we fuzzy generalized clustering algorithms allow to merge pixels according to their intensities. Then, fuzzy connectedness algorithm allows to merge pixels according to cost function related to distance, gradient distance and intensities. A validation is performed with a comparison between expert results made by manual drawing and purpose-made software results. Our software provides an automatic and reliable method to segment visceral and subcutaneous adipose tissue and additionally avoids in some case the problem of inhomogeneity of signal intensity

Les archives chorégraphiques entre mémoire et création

Les logiques d’usages des archives – entendons par là non seulement la finalité apparente de ces usages mais aussi le sens qu’y injecte l’usager – connaissent actuellement une diversification qui, par bien des aspects, paraît clore l’âge de l’usage exclusivement ou essentiellement historique qui s’était ouvert vers le milieu du XIXe siècle. De nouvelles formes de rapport aux documents d’archives s’instaurent, différentes de celles qui existent entre un historien et ses sources. Elles mettent en jeu d’autres registres, plus affectifs ou émotionnels, qui touchent à l’estime de soi, la construction des individus, les processus de subjectivation ou les mécanismes de production d’un roman familial. C’est dans ce contexte qu’il convient de situer l’archivage de la danse et les archives chorégraphiques, l’intensité des questionnements contemporains qu’ils suscitent, les spécificités, relatives sans doute, des réflexions qu’ils engendrent et l’existence de ce que l’on pourrait appeler une « archivistique artistique », c’est-à-dire un acte d’archivage intégré dans un processus de création artistique

Distribution of adipose tissue: Quantification and relationship with hepatic steatosis and vascular profiles of type 2 diabetic patients with metabolic syndrome

AimAs the distribution of fat is increasingly related to cardiovascular events, we examined whether or not abdominal-fat quantification using magnetic resonance imaging (MRI) software is reliable, and whether or not it is related to clinical markers of fat distribution as well as to metabolic and vascular status. Methods We recorded the anthropometric measurements of 34 obese type 2 diabetic patients with metabolic syndrome. The patients were enrolled to evaluate their abdominal (visceral and subcutaneous) adipose tissue by single-slice L3–L4 MRI. Manual and automated analyses were compared. The relationships between anthropometric measurements, biological markers and intima-media thickness of the common carotid artery were also assessed. Results We validated the automated software to quantify abdominal-fat deposition with MRI compared with manual measurements (r2 = 0.95). The waist-to-hip-circumference ratio (WHR) was the only clinical parameter that correlated with the proportion and quantity of visceral and subcutaneous abdominal-adipose tissue evaluated by MRI (r = 0.60). In addition, fat repartition as evaluated by WHR was related to hepatic steatosis parameters (ferritin and ALAT) and to intima-media thickness, whereas simple waist circumference was not a determinant in these obese patients. We also showed that the adiponectin-to-leptin ratio was related to adipose tissue distribution. Conclusion Distribution of abdominal fat, as evaluated by MRI, can be reflected by clinical determination of the WHR. Differences in regional accumulations of abdominal fat may be specifically related to variations in the risks of steatosis and vascular rigidity among obese type 2 diabetic patients

Non-invasive diagnosis of liver lesions by blood tests in NAFLD

Background and Aims: Non invasive tests are not well developedin NAFLD. This could be partly due to the pathological description of certain lesions that is hampered by semi-quantitative scorings. Our aim was to develop an accurate non-invasive measurement of main liver lesions in NAFLD by blood tests based on a thorough pathological and morphometric analysis. Methods: Steatosis, NASH and fibrosis were graded according to CRN-NASH (Kleiner, Hepatology 2005) and Metavir systems in 226 patients with NAFLD. A fully automated, in-house software measured the fractal dimension (reflecting architecture) and the area (reflecting amount) of steatosis or fibrosis on liver specimens. Independent predictors were selected by logistic or multiple regression repeated in 1000 random bootstrap samples. When models were determined, a second bootstrap resampling was performed to measure optimism bias (Steyerberg et al. 2001)

Chemical Diversity and Complexity of Scotch Whisky as Revealed by High-Resolution Mass Spectrometry

Scotch Whisky is an important product, both culturally and economically. Chemically, Scotch Whisky is a complex mixture, which comprises thousands of compounds, the nature of which are largely unknown. Here, we present a thorough overview of the chemistry of Scotch Whisky as observed by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Eighty-five whiskies, representing the majority of Scotch Whisky produced and sold, were analyzed by untargeted high-resolution mass spectrometry. Thousands of chemical formulae were assigned for each sample based on parts-per-billion mass accuracy of FT-ICR MS spectra. For the first time, isotopic fine structure analysis was used to confirm the assignment of high molecular weight CHOS species in Scotch Whisky. The assigned spectra were compared using a number of visualization techniques, including van Krevelen diagrams, double bond equivalence (DBE) plots, as well as heteroatomic compound class distributions. Additionally, multivariate analysis, including PCA and OPLS-DA, was used to interpret the data, with key compounds identified for discriminating between types of whisky (blend or malt) or maturation wood type. FT-ICR MS analysis of Scotch Whisky was shown to be of significant potential in further understanding of the complexity of mature spirit drinks and as a tool for investigating the chemistry of the maturation processes. [Figure: see text] ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s13361-016-1513-y) contains supplementary material, which is available to authorized users

Noninvasive liver steatosis quantification using MRI techniques combined with blood markers:

Aims: To evaluate the accuracy of different techniques of MRI steatosis quantification, based on histological grading and quantification of liver steatosis.Patients and methods: Twenty-three patients (21 with nonalcoholic fatty liver disease and two controls) were included. Steatosis was evaluated in liver specimens using histological grading (five grades) and steatosis area (% of liver surface) was computed using an inhouse automated image analysis. The following five MRI quantification techniques were performed: two-point Dixon, three-point Dixon, DUAL, spin echo method and a new technique called multi-echo gradient-echo (MFGRE). Interobserver (two observers) and intersite (three different liver sites) agreements were evaluated for the two best-performing methods. Results: Steatosis area was correlated with steatosis grade: Rs (Spearman coefficient)=0.82, P value of less than 0.001. The steatosis area was significantly different between S0–S2 and S3–S4 grades: 4.2±2.4 versus 16.4±8.9% (P<0.001). Correlations between the MRI techniques and steatosis area (or grading) were: MFGRE, Rs=0.72 (0.78); spin echo method, Rs=0.72 (0.76); DUAL, Rs=0.71 (0.76); two-point Dixon, Rs=0.71 (0.75); three-point Dixon, Rs=0.67 (0.77). Interobserver (Ric=0.99) and intersite (Ric=0.97) agreements were excellent for the liver steatosis measurement by MFGRE. The noninvasive diagnosis of the steatosis area was improved by adding blood markers like ALT and triglycerides to MFGRE (aR2: 0.805). Conclusion: MRI, and in particular the MFGRE method, provides accurate and automatic quantification for the noninvasive evaluation of liver steatosis, either as a single measurement or in combination with blood variables

Distribution of abdominal adipose tissue as a predictor of hepatic steatosis assessed by MRI

AIM: To evaluate the relationship between the distribution of visceral and subcutaneous adipose tissue and hepatic steatosis assessed using magnetic resonance imaging (MRI). MATERIALS AND METHODS: One T1-weighted, in-/out-of-phase, single-section sequence at the L3/L4 level and one multi-echo gradient MRI (MGRE) sequence were performed on 65 patients [19 females and 46 males; age 57+/-9.5 years; body mass index (BMI) 31+/-5.1kg/m(2)]. Visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) surfaces, and hepatic steatosis were automatically calculated using in-house software. Weight, height, BMI, waist circumference, hip circumference, and waist:hip ratio were recorded. The probability of having a steatosis greater than 10% on MRI was evaluated by receiver operating characteristic (ROC) curves. RESULTS: The anthropometric parameter best correlated to hepatic steatosis was the waist-to-hip ratio (r=0.301). VAT and proportion of VAT were correlated to liver fat content (r=0.307 and r=0.249, respectively). No significant correlations were found for BMI, hip circumference, and SAT. The area under the receiver operating characteristics (AUROCs) for the relationship between liver steatosis and BMI, waist circumference, waist:hip ratio, VAT surface, and proportion of VAT, were respectively 0.52, 0.63, 0.71, 0.73 and 0.75. CONCLUSION: Adipose tissue distribution is more relevant than total fat mass when assessing the possibility of liver steatosis in overweight patients