A new procedure, free from human assessment, that automatically grades some facial skin signs in men from selfie pictures. Application to changes induced by a severe aerial chronic urban pollution.

OBJECTIVE: These were two folds: at first, to develop an automatic grading system specifically dedicated to some facial signs of men, similar to the one previously validated on women of different ethnic ancestry and second, to assess its potential in detecting and grading the possible impacts of a severe aerial urban pollution on some facial signs of Chinese men. METHODS: In both studies, selfie images were obtained from differently aged men. Nine facial signs were automatically graded through a specific A.I-based algorithm and clinically assessed by a panel of experts and dermatologists. Selfie pictures were taken from individual smartphones of variable optical properties. The first study, designed for developing an automatic grading system, involved three comparable cohorts of men from three different regional ancestries (African, Asian, Caucasian, 110 each) the selfie images of which were acquired under four different lighting conditions. As a second use case study, the facial signs of two cohorts of Chinese men (101 and 100, each), differently aged, regularly exposed to very different aerial urban pollution conditions (UP) were analysed by the same algorithm, selfies being taken under only one lighting condition. RESULTS: -The new automatic grading system of facial signs suits well to men, showing comparable results than that the one dedicated to women and provides data in close agreement with experts' assessments. -In both cases (expert's or automatic methodology), the accuracy of the scores appeared ethnic-dependent. -The applied case confirmed previous results obtained clinically, that is, that many facial signs were found of an increased severity among men exposed to a severe urban pollution, as compared to those living in a less polluted city. -In both studies, statistical agreements between the automatic grading system and expert's assessments were reached. In some facial signs, the automatic grading system seems offering a slightly better accuracy than the assessments made by the experts. CONCLUSION: Apart from some minor limitations, this A.I-based automatic grading system, free from human intervention, performed as well as the one previously developed in women, in close agreement with expert's assessments. In epidemiological studies, this system offers an easy, fast, affordable and confidential approach in the detection and quantification of male facial signs.

OBJECTIF: Il était double: (i) de développer d'un système automatique de scorage spécifique de plusieurs signes faciaux pour les hommes, similaire à celui précédemment validé sur des femmes de différentes origines. Et (ii), de jauger ses capacités pour la détection et l'évaluation des possibles impacts d'une pollution aérienne urbaine sévère sur le visage d'hommes chinois. MÉTHODES: Dans chacune des deux études des images de type selfies d'hommes de différents âges ont été obtenues. Neuf signes faciaux ont été automatiquement évalués grâce à un algorithme spécifique basé sur l'Intelligence Artificielle (IA) puis scorés cliniquement par un panel d'experts et de dermatologues. Des selfies ont été acquis à partir de téléphones portables individuels possédants des optiques et des résolutions différentes. L'étude N°1, conçue pour développer un système de scorage automatique du visage, a regroupé trois cohortes comparables d'hommes d'origines géographiques différentes (Africain, Asiatique et Caucasien, 110 volontaires par ethnies) et a requis l'acquisition sous 4 conditions d'éclairage. L'étude N°2, comme cas pratique, a nécessité le recrutement de deux cohortes d'hommes chinois d'âges différents (101 et 101 volontaires chacune) exposés régulièrement à de très différentes conditions de pollution aérienne urbaine et pour lesquels des selfies ont été enregistrés sous une seule condition d'éclairage. RÉSULTATS: -Le nouveau système de scorage automatique de signes faciaux des hommes performe de manière satisfaisante et montre des résultats comparables à celui précédemment conçu pour les femmes et donne des mesures très proches des évaluations cliniques des experts et dermatologues. -Dans les deux cas (experts ou mesures automatiques), l'acuité des scores apparaît dépendante à l'origine ethnique. -Le cas pratique confirme nos résultats précédents obtenues cliniquement, c'est à dire que de nombreux signes faciaux ont été trouvés d'amplitude plus importante pour les hommes exposés à une pollution aérienne urbaine sévère en comparaison de ceux vivant dans une ville moins polluée. -Les deux études ont démontré l'adéquation statistique entre le système automatique et les évaluations des experts et dermatologues. Pour certains signes, une certaine supériorité de système automatique a pu être observée vis-à-vis de l'évaluation des experts. CONCLUSION: A l'exception de quelques limitations mineures, le nouveau système de scorage automatique, basé sur l'IA, du visage des hommes - ne nécessitant aucune intervention humaine - fonctionne aussi bien que celui dédié aux femmes et toujours en parfaite adéquation avec les dermatologues. Pour des études épidémiologiques, ce système offre une approche rapide, aisée, confidentielle et d'un coût très abordable pour la détection et la quantification des signes faciaux masculins.

An automatic procedure that grades some facial skin structural signs: agreements and validation with clinical assessments made by dermatologists.

OBJECTIVE: To confirm the robustness and validity of an automatic scoring system, algorithm-based, that grades the severity of nine facial signs through "selfies" smartphones pictures taken by European Caucasian women through dermatological assessments. METHODS: 157 Caucasian women from three countries (France, Germany, Spain), of different ages (20-75 years), took one "selfie" image by the frontal camera of their smartphones whereas local dermatologists photographed them with the back camera of the same smartphone. The same nine facial signs of these subjects were initially graded by these local dermatologists, using referential Skin Aging Atlases. All 314 "selfies" images were then further automatically analyzed by the algorithm. The severity of facial signs (wrinkles, pigmentation, ptosis, skin folds etc.) were statistically compared to the assessments made by the three dermatologists, taken as ground truth. RESULTS: Highly significant coefficients of correlation (P < 0.001) were found in the three cohorts between the grades provided by the system and those from dermatologists in live. The back camera - of a better resolution than the frontal one - seems affording slightly more significant correlations. However, although significantly correlated, the signs of vascular disorders and cheek skin pores present some disparities that are likely linked to the technical diversity of smartphones or self-shootings, leading to lower coefficients of correlations. CONCLUSION: This automatic scoring system offers a promising approach in the harmonization of Dermatological assessments of skin facial signs and their changes with age or the follow up of anti-aging treatments.

OBJECTIF: De confirmer la validité et la solidité d'un système de scorage automatique qui quantifie la sévérité de neuf signes du visage à partir de photographies de type "selfies" prises par des femmes Caucasiennes Européennes d'âge différents. MÉTHODES: 157 femmes Caucasiennes de trois pays différents (France, Allemagne, Espagne), d'âges différents (20-75 ans) ont pris un « selfie¼ avec la caméra frontale de leur téléphone tandis que le dermatologue local les a photographiées à l'aide de la caméra dorsale du même appareil. Les neuf signes faciaux ciblés par le système de scorage automatique ont été préalablement évalués par trois dermatologues locaux, utilisant des Atlas référentiels du vieillissement cutané. Les 314 images obtenues furent ensuite analysées automatiquement par l'algorithme. Les sévérités des neuf signes (rides, ptose, plis, pigmentation...) ont été ensuite comparées à celles établies par les dermatologues, considérées comme références absolues. RÉSULTATS: De très significatifs coefficients de corrélation (P < 0.001) ont été trouvés dans les trois cohortes entre les scores fournis par le système et ceux issus des évaluations des dermatologues des visages durant la visite des volontaires. La caméra du dos des smartphones - de meilleure résolution que la frontale - semble fournir de légèrement meilleures significativités. Cependant, bien que significativement corrélés, les signes des désordres vasculaires et des pores cutanés des joues montrent quelques disparités, dues possiblement à la diversité technique des smartphones ou celle des prises de vue, conduisant à de plus faibles coefficients de corrélation. CONCLUSION: Ce système de quantification automatique semble offrir une approche prometteuse dans l'harmonisation des évaluations dermatologiques des signes faciaux et leurs modifications liées à l'âge et/ou le suivi de traitements à vocation antivieillissement cutané.

Spherical wavelet transform for ODF sharpening.

The choice of local HARDI reconstruction technique is crucial for discerning multiple fiber orientations, which is itself of substantial importance for tractography, and reliable and accurate assessment of white matter fiber geometry. Due to the complexity of the diffusion process and its milieu, distinct diffusion compartments can have different frequency signatures, making the HARDI signal spread over multiple frequency bands. Therefore, we put forth the idea of multiscale analysis with localized basis functions, ensuring that different frequency ranges are probed. With the aim of truthful recovery of fiber orientations, we reconstruct the orientation distribution function (ODF), by incorporating a spherical wavelet transform (SWT) into the Funk-Radon transform. First, we apply and validate our proposed SWT method on real physical phantoms emulating fiber bundle crossings. Then, we apply the SWT method to a real brain data set. The analysis of the real data set suggests that different angular frequencies may capture different information, thus stressing the importance of multiscale analysis. For both phantom and real data, we compare the SWT reconstruction with state-of-the-art q-ball imaging and spherical deconvolution reconstruction methods. We demonstrate the algorithm efficiency in diffusion ODF denoising and sharpening that is of particular importance for applications to fiber tracking (especially for probabilistic approaches), and brain connectome mapping. Also, the algorithm results in considerable data compression that could prove beneficial in applications to fiber bundle segmentation, and for HARDI based white matter morphometry methods.

Atrophy in white matter fiber tracts in multiple sclerosis is not dependent on tract length or local white matter lesions.

The pathogenesis of tissue injury outside the white matter (WM) plaques of multiple sclerosis (MS) has not yet been clearly defined. To better understand the pathogenesis of this injury and the associated atrophy, we investigated volume loss over time in 20 WM fiber tracts. We defined two main aims: (1) to examine whether certain fiber tracts were more prone to atrophy, and to test the possible relation of tract atrophy to tract length and selected MS-specific variables; and (2) to investigate the possible relation of atrophy to lesion load (whole brain and in the specific tract). Local volume change was assessed between two distant time points for each MS patient studied. Fiber tracts were segmented automatically using a tractography-based atlas. Results demonstrate volume loss in all fiber tracts. The uncinate fasciculus and anterior-thalamic radiation had the greatest yearly percentage atrophy. Disease type, duration, median expanded disability status scale, total lesion load, and gender exhibited significant effects on atrophy in at least one tract. Together, these data are more consistent with a pathogenesis for the degeneration related to diffuse inflammation rather than the secondary effects of focal lesions.

The relation of focal white matter signal abnormality and focal volume loss in multiple sclerosis.

There were two aims to this study. First, to explore how the reduction in the volume of abnormal T2-signal intensity associated with white matter (WM) lesions in multiple sclerosis (MS) relates to tissue loss resulting from focal pathology inside lesions. Second, to demonstrate that this volume of abnormal T2-signal intensity underestimates the actual size of the region to which the direct effects of lesion activity extend. For these purposes, we used deformation field analysis to quantify the evolution of local atrophy associated with a chronic peri-ventricular lesion in a patient with secondary progressive MS. This subject had particular features that may not necessarily co-exist in a group of unselected patients, which enabled interesting observations to be made. We show, quantitatively, that the focal WM lesion was associated with adjacent regional WM volume loss, which was disproportionate to concurrent diffuse atrophy in the rest of the normal appearing brain tissue, and that the loss of volume associated with the lesion was partially reciprocated by local ventricular expansion. Our observations re-emphasise the complex relationship between the change in the volume of abnormal signal intensity on magnetic resonance images and the tissue volume change directly related to lesion pathology.