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Chloé Chamard,1,2 Jerome J Maller,3,4 Nicolas Menjot,5 Eloi Debourdeau,1 Virginie Nael,6 Karen Ritchie,2,7 Isabelle Carriere,2,* Vincent Daien1,2,8,* 1Department of Ophthalmology, Gui de Chauliac Hospital, Montpellier, F-34000, France; 2Institute for Neurosciences of Montpellier INM, University Montpellier, INSERM, Montpellier, F-34091, France; 3General Electric Healthcare, Melbourne, VIC, Australia; 4Monash Alfred Psychiatry Research Centre, Melbourne, VIC, Australia; 5Department of Neuroradiology, Gui de Chauliac Hospital, Montpellier, F-34000, France; 6Bordeaux Population Health Research Center, UMR 1219, University Bordeaux, INSERM, Bordeaux, F-33000, France; 7Department of Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK; 8The Save Sight Institute, Sydney Medical School, the University of Sydney, Sydney, NSW, Australia*These authors contributed equally to this workCorrespondence: Chloé Chamard, Department of Ophthalmology, Gui de Chauliac Hospital, 80 avenue Augustin Fliche, Montpellier, F-34000, France, Tel +33 6 33 55 65 06, Email chloe.chamard@gmail.comPurpose: Visual impairment is a major cause of disability and impairment of cognitive function in older people. Brain structural changes associated with visual function impairment are not well understood. The objective of this study was to assess the association between visual function and cortical thickness in older adults.Methods: Participants were selected from the French population-based ESPRIT cohort of 2259 community-dwelling adults ≥ 65 years old enrolled between 1999 and 2001. We considered visual function and brain MRI images at the 12-year follow-up in participants who were right-handed and free of dementia and/or stroke, randomly selected from the whole cohort. High-resolution structural T1-weighted brain scans acquired with a 3-Tesla scanner. Regional reconstruction and segmentation involved using the FreeSurfer image-analysis suite.Results: A total of 215 participants were included (mean [SD] age 81.8 [3.7] years; 53.0% women): 30 (14.0%) had central vision loss and 185 (86.0%) normal central vision. Vision loss was associated with thinner cortical thickness in the right insula (within the lateral sulcus of the brain) as compared with the control group (mean thickness 2.38 [0.04] vs 2.50 [0.03] mm, 4.8% thinning, pcorrected= 0.04) after adjustment for age, sex, lifetime depression and cardiovascular disease.Conclusion: The present study describes a significant thinning of the right insular cortex in older adults with vision loss. The insula subserves a wide variety of functions in humans ranging from sensory and affective processing to high-level cognitive processing. Reduced insula thickness associated with vision loss may increase cognitive burden in the ageing brain.Keywords: visual function, vision, cortical thickness, brain, morphometry, MRI

International audience; Background: Glucometabolic changes, such as high glycemic load (GL) diet and insulin resistance (IR), are potential risk factor of Alzheimer's disease (AD). Yet, the effect of these factors on brain alterations that contribute to AD pathology has not been clearly demonstrated.Objective: We aimed to assess the relationship of GL and IR with gray matter volumes involved in prodromal dementia.Methods: GL and Triglyceride-Glucose (TyG) index, an IR surrogate marker, were calculated in 497 participants who underwent magnetic resonance imaging (MRI). The gray matter volumes most related to prodromal dementia/mild cognitive impairment (diagnosed in 18/158 participants during the 7-year follow-up) were identified using a data-driven machine learning algorithm.Results: Higher GL diet was associated with reduced amygdala volume. The TyG index was negatively associated with the hippocampus, amygdala, and putamen volumes.Conclusion: These results suggest that GL and IR are associated with lower gray matter volumes in brain regions involved in AD pathology.

International audience; The paper presents a new methodology for the numerical estimation of the Green's functions in complex external aeroacoustic configurations. Computational aeroacoustics is used to propagate multi-frequency signals from focus points to microphones. The method takes advantage of the sparsity of the Green's functions in the time-domain to minimize the simulation time. It leads to a complex sparse linear regression problem. To solve it, the Orthogonal Matching Pursuit algorithm is adapted. The method is first applied on the case of the diffraction by a rigid sphere. Results are studied both in terms of Green's function estimation and aeroacoustic beamforming. They show that the Green's functions are obtained with a good accuracy and enable to localize acoustic sources placed behind the diffracting object. The methodology is then applied on a NACA0012 2D wing in a potential flow for which the Green's function is not known analytically. The use of the reverse-flow reciprocity principle enables to reduce the complexity of the estimation problem when there are more scan points than microphones. It is shown that it is possible to take advantage of the presence of diffracting objects to improve the capability of detection of a sensor array.

International audience; Purpose - The area of left ventricular (LV) pressure-strain loop (PSL) is used as an index of regional myocardial work. The purpose of the present work is to compare the main segmental PSL markers and the derived global work indices, when they are calculated using an estimated pressure signal or an observed pressure signal.Methods and results - In nine patients implanted with a bi-ventricular pace-maker (CRT), LV pressure was invasively measured in five conditions: CRT-off, LV-pacing, right ventricular-pacing and two different CRT-pacing. For each condition, systolic blood pressure was measured by brachial artery cuff-pressure and transthoracic echocardiography loops were recorded simultaneously. The error and relative root mean square error (rRMSE) between measured and estimated pressure were calculated for each patient and each configuration. Correlation coefficient (R2) and Bland-Altman (BA) analysis were performed for PSL area and work indices. A total of 43 different haemodynamic conditions were compared (774 segmental PSL). The global rRMSE between estimated and measured LV-pressure was 12.3 mmHg. The estimated and measured segmental LV-PSL were strongly correlated, with an R2 of 0.98. BA analysis shows that the mean bias for the estimation of segmental LV-PSL area is 86.0 mmHg.%. A significant bias effect with linearly increasing error with pressure values is observed. R2 ≥ 0.88 and a mean bias in BA analysis ≤41.4 mmHg.% was observed for the estimation of global myocardial work indices.Conclusion - The non-invasive estimation for LV pressure-strain loop area and the global myocardial work indices obtained from LV-PSL strongly correlates with invasive measurements.

Increasingly more patients exposed to radiation from computed axial tomography (CT) will have a greater risk of developing tumors or cancer that are caused by cell mutation in the future. A minor dose level would decrease the number of these possible cases. However, this framework can result in medical specialists (radiologists) not being able to detect anomalies or lesions. This work explores a way of addressing these concerns, achieving the reduction of unnecessary radiation without compromising the diagnosis. We contribute with a novel methodology in the CT area to predict the precise radiation that a patient should be given to accomplish this goal. Specifically, from a real dataset composed of the dose data of over fifty thousand patients that have been classified into standardized protocols (skull, abdomen, thorax, pelvis, etc.), we eliminate atypical information (outliers), to later generate regression curves employing diverse well-known Machine Learning techniques. As a result, we have chosen the best analytical technique per protocol, a selection that was thoroughly carried out according to traditional dosimetry parameters to accurately quantify the dose level that the radiologist should apply in each CT test.

International audience; The multi-modality cardiovascular imaging journal, European Heart Journal-Cardiovascular Imaging, was created in 2012. It has gained an impressive impact factor of 5.99 during its first 5 years and is now the most important imaging journal in Europe. The most important studies from the journal's fourth and fifth years will be highlighted in two reports. Part I of the review will focus on studies in myocardial function, myocardial ischaemia, and emerging techniques in cardiovascular imaging and Part II will focus on valvular heart diseases, heart failure, cardiomyopathies, and congenital heart diseases.

International audience; OBJECTIVE: The aim of this study was to test a new automated hepatic volumetry technique by comparing the accuracies and postprocessing times of manual and automated liver volume segmentation methods in a patient population undergoing orthotopic liver transplantation so that liver volume could be determined on pathology as the standard of reference. CONCLUSION: Both manual and automated multiphase MDCT-based volume measurements were strongly correlated to liver volume (Pearson correlation coefficient, r = 0.87 [p < 0.0001] and 0.90 [p < 0.0001], respectively). Automated multiphase segmentation was significantly more rapid than manual segmentation (mean time, 16 ± 5 [SD] and 86 ± 3 seconds, respectively; p = 0.01). Overall, automated liver volumetry based on multiphase CT acquisitions is feasible and more rapid than manual segmentation.

International audience; We propose a new imaging technique, demonstrating the bones' edges using the Silent Scan's T1w FatSat sequence. An advanced post-processing coupled with the use of the zero echo-time imaging technology could lead to robust semi- or automatic segmentation. Such technique could guide and facilitate every surgery that needs bone measurements and valuable 3D appreciation or virtual guiding.

This work received funding from the European Union´s Horizon 2020 research and innovation programme under grant agreement No 777657; International audience; For decades, scientists have looked for the causes of cell cryoinjury so as to identify the optimum conditions for freezing and storing frozen cells. Cell dehydration and intracellular ice formation have been argued as the main mechanisms of cell damage. Maintaining the cells in a vitreous matrix below the glass transition temperature of the surrounding medium is known as a key condition for cell preservation. However, it is only in 2013 that the measurement of the intracellular glass transition of different cell types has been made possible. Moreover, the relevance of intracellular and extracellular vitrification during slow cooling of microorganisms and mammalian cells has been the subject of recent research. The physical events taking place during freezing are reviewed here, focusing on the role of the physical state of the intracellular and extracellular environments in determining the response of cells to stresses encountered during cryopreservation. The implications on cryoprotectants selection, freezing rates, and controlled cooling endpoint to be set for cell storage are discussed.