Automatic 3D segmentation of multiphoton images: a key step for the quantification of human skin

Abstract

This study shows that multiphoton microscopy associated with specific image processing tools provides access to new quantitative measurements on the various skin components. The proposed 3D automatic segmentation method will contribute to build a powerful tool for characterizing human skin condition. To our knowledge, this is the first 3D approach to the segmentation and quantification of these original images.

L’imagerie multiphoton des peaux naturelles et synthétiques. Un nouvel outil pour l’évaluation des produits cosmétiques

“…L'analyse des images est alors une étape critique pour accéder à des paramètres de structure quantitatifs et pouvoir comparer divers échantillons. Ceci nécessite encore des développements, notamment pour réaliser une véritable analyse 3D [5]. Par ailleurs, il est possible d'effectuer une analyse polarimétrique des signaux SHG et d'accéder ainsi plus précisément à la direction des fibres de collagène.…”

19 Multiphoton FLIM in cosmetic clinical research

“…Nowadays commercial microscopes clinically/medically approved for their use on humans exist, in either tabletop (DermaInspect™, since 2002) or in a more flexible, compact and "portable" configuration (MPTflex™, since 2011) more suitable for clinical use [45]. The clinical applications of in vivo multiphoton/FLIM microscopy range from the characterization of age-related or photoaging changes [38,[46][47][48][49][50][51][52][53][54][55]], dermatological disorders and melanoma [28,[56][57][58][59][60][61][62][63][64][65][66][67][68][69][70][71], up to the assessment of penetration and effects of pharmaceutical/cosmetic products on human skin [19,21,55,[72][73][74][75][76][77][78][79][80][81].…”

“…Moreover, the current version of the segmentation method, which has not undergone any specific computational optimization, takes an average of one minute to process a 3D multiphoton image on a classical personal computer (Intel core i7, 8 GB memory). For details, we refer the reader to [38]. At this stage, an epidermis mask, i.e., a 3D binary image corresponding to the epidermis compartment is available for further processing.…”

“…But neither of these parameters was assessed in the 3D epidermal or dermal volume. In the past years, our team focused on segmenting the multiphoton images in order to automatically separate the epidermis from the dermis [38] and validating 3D quantification parameters of interest for the study of photoaging or whitening phenomena [19][20][21]50]. We developed a user-friendly software, the Multiphoton Skin Tools Suite (MPSTS), allowing to choose a set of 3D acquisitions, build the list of measures to compute and run a batch processing to compute all the segmentations as well as the measures for an entire clinical study.…”

“…We classify the quantitative parameters extracted from skin multiphoton images into morphological and density measures (see Fig. 19.2) [38].…”