This research evaluated photonic imaging devices for assessment of body size and shape. In aim one, laser imaging measurements of circumference, volume, and % fat were examined in 70 women. Bland-Altman analysis indicated minimal error in girth of the waist and hip by laser imaging as compared to tape measure (95% limits of agreement for waist, -2.02-2.29 cm; hip, -3.39-2.90 cm). Volume by laser imaging was related to hydrodensitometry (r = 0.99, p < 0.01), and % fat estimates were not significantly different from hydrodensitometry or dual energy X-ray absorptiometry (DXA) (3.95 ± 1.74, 32.54 ± 1.28, and 35.86 ± 1.06, respectively, p > 0.05). In aim two, 120 adults were evaluated via stereovision imaging. Stereovision was significantly related to volume by air displacement plethysmography (ADP) and hydrodensitometry (R² > 0.99, p < 0.01). However, Bland-Altman analysis indicated variations in body fat between stereovision and ADP (95% limits of agreement, -16.77-16.05 kg). Therefore, aim three was development of a prediction equation to estimate fat from 13 stereovision measurements of body size and shape. These parameters combined to form upper and lower body factor scores, which, with gender, predicted 88.6% of variation in fat mass by ADP (p < 0.01). The equation improved 95% limits of agreement from -16.77-16.05 kg via direct volume measurement to -11.47-8.45 kg compared to ADP. Finally, in aim four, a subset of 56 women from aim two was evaluated for visceral fat by magnetic resonance imaging (MRI). Visceral fat was compared to a new indicator of abdominal adiposity via stereovision imaging: central obesity depth. Central obesity depth was correlated with visceral fat, following adjustment for age and ethnicity (r = 0.75, p < 0.01). Additionally, each 1 cm rise in central obesity depth raised the odds of being in the high versus low visceral fat tertile (Odds Ratio 8.59, 95% Confidence Interval 1.33-55.63, p < 0.05). Thus, both laser and stereovision body imaging appear to be valid techniques for evaluation of body size and shape. Furthermore, central obesity depth is a promising new measurement for assessment of visceral adiposity. / text

Le troisième Plan Cancer lancé en 2013 désigne la précocité du diagnostic comme l'un des enjeux majeurs pour l'amélioration de la prise en charge des patients. Malgré l’essor des modalités et des performances de l’imagerie médicale, il reste des défis à relever pour l’aide au diagnostic et optimiser le recourt à la biopsie.L’imagerie photonique et spécialement la fluorescence résolue spectralement a déjà été éprouvée pour la caractérisation ex vivo des tumeurs mammaires et pulmonaires, sans agent de contraste ou traitement des échantillons. Notre objectif est de caractériser les capacités d'un dispositif médical innovant, développé au laboratoire, utilisant une aiguille fibrée de faible calibre pour l’analyse spectrale de la fluorescence endogène de ces lésions in situ. Nos premiers travaux dans le cadre d’études précliniques et cliniques ont montré des différences significatives de signatures spectrales entre tumeurs bénignes et malignes ex vivo et in vivo. Nos résultats ont également mis en évidence les limites d’utilisation du dispositif, en termes de spécificité, pour certains types de lésions.Une étude secondaire a été entreprise sur des tumeurs mammaires afin d'identifier les entités tissulaires majeures à l'origine des signatures spectrales obtenues avec notre dispositif fibré. L'imagerie spectrale en microscopie confocale et seconde harmonique (SHG), en multiphoton, ont été mises en œuvre afin d’établir une cartographie de biomarqueurs endogènes des tissus mammaires. Nous avons confronter ses résultats aux données obtenues avec le dispositif d'aiguille fibrée afin de pouvoir le positionner non seulement comme une aide au diagnostic mais aussi comme une méthode prometteuse pour l’histopathologie in situ. / The third Cancer Plan, launched in 2013, identifies early diagnosis as one of the major challenges for improving patient care. Despite the growth in medical imaging modalities and performance, challenges remain in diagnosis aid and optimizing the use of biopsy.Photonic imaging and especially spectrally resolved fluorescence has already been tested for the ex vivo characterization of breast and lung tumors, without contrast agent or sample processing. Our goal is to characterize the capabilities of an innovative medical device, developed in the laboratory, using a low-caliber fibered needle for the spectral analysis of the endogenous fluorescence of these lesions in situ. Our early work in preclinical and clinical studies showed significant differences in spectral signatures between benign and malignant tumors ex vivo and in vivo. Our results also highlighted the limits the device, in terms of specificity, for certain types of lesions.Another study was conducted on mammary tumors in order to identify the major tissue entities at the origin of the spectral signatures obtained with our fibered device. Spectral imaging in confocal and second harmonic microscopy (SHG), in multiphoton, has been implemented in order to establish a mapping of endogenous biomarkers of mammary tissues. We compare its results with the data obtained with the fibered needle device in order to position it not only as an aid to diagnosis but also as a promising method for in situ histopathology.