Numerical study of an optimization problem for mosaic active imaging

5International audienceIn this paper, we focus on the restoration of an image in mosaic active imaging. This emerging imaging technique consists in acquiring a mosaic of images (laser shots) by focusing a laser beam on a small portion of the target object and subsequently moving it to scan the whole field of view. To restore the whole image from such a mosaic, a prior work proposed a simplified forward model describing the acquisition process. It also provides a prior on the acquisition parameters. Together with a prior on the distribution of images, this leads to a MAP estimate alternating between the estimation of the restored image and the estimation of these parameters. The novelty of the current paper is twofold: (i) We provide a numerical study and argue that faster convergence can be achieved for estimating the acquisition parameters; (ii) we show that the results from this earlier work are improved when the laser shots are acquired according to a more compact pattern

Bayesian image restoration for mosaic active imaging

International audienceIn this paper, we focus on the restoration of images acquired with a new active imaging concept. This new instrument generates a mosaic of active imaging acquisitions. We first describe a simplified forward model of this so-called ''mosaic active imaging''. We also assume a prior on the distribution of images, using the \ac{TV}, and deduce a restoration algorithm. This algorithm iterates one step for the estimation of the restored image and one step for the estimation of the acquisition parameters. We then provide the details useful to the implementation of these two steps. In particular, we show that the image estimation can be performed with graph-cuts. This allows a fast resolution of this image estimation step. Finally, we detail numerical experiments showing that acquisitions made with a mosaic active imaging device can be restored even under severe noise levels, with few acquisitions

Direct physical modelling and scene reconstruction in order to assess the performance from a new concept of active imaging: Mosaic active imaging system

International audienceActive imaging can be used for surveillance or target identification at long range and low visibility conditions. Its principle is based on the illumination of a scene with a pulsed laser which is then backscattered to the sensor. The signal to noise ratio and contrast of the object over the background are increased in comparison with passive imaging. Even though, range and field of view (FOV) are limited for a given laser power. A new active imaging system presented here aims at overcoming this limitation. It acquires the entire scene with a high-speed scanning laser illumination focused on a limited region, whereas at each scan the full frame active image is acquired. The whole image is then reconstructed by mosaicking all these successive images. A first evaluation of the performance of this system is conducted by using a direct physical model. This end-to-end model, realistic in terms of turbulence effects (scintillation, beam wandering ...), gives us a sequence of images a synthetic scenes. After presenting this model, a reconstruction method of the total scene is described. And the performances of this new concept are compared to those of a conventional flash active camera by using usual metrics (SNR, MTF ...). For various mean laser powers, we quantify the gains expected in terms of range and field of view of this new concept

Prevalence and spectrum of SDHx mutations in pheochromocytoma and paraganglioma in patients from Belgium: an update

Since the early 2000s, the prevalence and spectrum of mutations in genes encoding subunits of succinate dehydrogenase (SDHx) were reported in large cohorts of patients with pheochromocytoma (PC) and paraganglioma (PGL) from most Western countries. Unfortunately, in Belgium, no equivalent work was performed thus far. Therefore, the aim of the work was to look for mutations in SDHx genes and genotype-phenotype correlations in patients with PC and/or PGL from Belgium. Screening of the coding parts of SDHx genes and deletion search were performed in all patients with PC and/or PGL referred to the Cliniques Universitaires Saint-Luc from 05/2003 to 05/2011. Genetic screening was performed in 59 unrelated head and neck (hn)PGLs (8 fami lial) and 53 PCs (7 extra-adrenal; 3 metastatic). In hnPGLs, 10 diff erent SDHD mutations (3 substitutions, 5 deletions, 2 splice site mutations) were detected in 16 patients, including 7 familial cases and 9 apparently sporadic cases. In the same subset, we found 8 diff erent SDHB mutations (5 substitutions, 1 splice ite mutation, 1 deletion, 1 duplication) in 10 patients with sporadic hnPGL without evidence of malignancy. No SDHx mutation was detected in patients harboring PCs and no SDHC mutation whatsoever. In conclusion, in our multicentric database of PC-PGLs from Belgium, (i) the prevalence of SDHx mutations was high in hnPGLs (44 % in the whole subset, 37 % of apparently sporadic cases); (ii) in sporadic cases, the prevalence of SDHB mutations was high (20 %), similar to that of SDHD (18 %); and (iii) no SDHx mutation was found in a subset of mostly adrenal, benign PCs

Yearly incidence of rhinitis, nasal bleeding, and other nasal symptoms in mature women.

OBJECTIVES/HYPOTHESIS: To evaluate, by a prospective questionnaire study, the incidence of spontaneous nasal pathology in mature women over a 12-month period, in particular nasal bleeding and the relationships of these symptoms with various factors. METHODS: Participants were drawn from a sample of 12,735 adult French volunteers participating in a study of antioxidant nutrients ("SU.VI.MAX"); 3500 women aged 50-64 years were randomly selected from good responders in the SU.Vl.MAX population. The responses of 2197 women were analysed. RESULTS: Nearly 70% of subjects reported at least one episode of rhinitis, with a mean (SD) of 1.88 (2.17) episodes per subject. Rhinitis was related to passive exposure to tobacco smoke (adjusted odds ratio [OR] 1.31, 95% CI 1.05-1.63), menopause (OR 1.47, 95% CI 1.16-1.88), and occupational exposure to vapours or dusts (OR 1.55, 95% CI 1.01-2.37). Nasal bleeding was reported as traces of blood by 16.5% of subjects, and as epistaxis (significant nasal bleeding) by 7.6%. Both symptoms were related to passive exposure to tobacco smoke (OR 1.63, 95% CI 1.22-2.19; OR 1.56, 95% CI 1.05-2.32, respectively) but not to use of systemic or topical medication. CONCLUSION: A substantial number of mature women experience nasal symptoms during the course of a year. Rhinitis and nasal bleeding were correlated with passive exposure to tobacco smoke

Reliability of MSTC, Malnutrition Screening Tool for Cancer patients, in an Outpatient Clinic setting

MSTC seems to be useful as undernutrition screening tool in adult cancer patients. The 3 pre-categories need to be objectively identifie

High prevalence of SDHB mutations in head and neck paraganglioma in Belgium

BACKGROUND: Recent reports have found genetic mutations in up to one quarter of patients harbouring pheochromocytoma and/or paraganglioma. This high prevalence was mainly due to the discovery of the role of SDH genes. While SDHD has been more frequently associated with the pathogenesis of head and neck paragangliomas, SDHB mutations were mainly associated with malignant and/or extra-adrenal pheochromocytoma/paraganglioma. OBJECTIVE: To look for mutations in susceptibility genes and genotype-phenotype correlations in patients with pheochromocytoma and/or paraganglioma from Belgium. METHODS: Screening of the coding parts of SDH, VHL and RET genes was performed by SSCP in patients with pheochromocytoma and/or paraganglioma diagnosed at or referred to the Cliniques Universitaires Saint Luc from May 2003 to May 2006. RESULTS: Fifty-six unrelated patients were included (36 head and neck paragangliomas, including six familial cases and 30 sporadic cases; 18 abdominal pheochromocytoma/paraganglioma and two paraganglioma of the cauda equina). The overall prevalence of mutations was 41% (n = 23 including 19 head and neck paragangliomas and four abdominal pheochromocytoma/paraganglioma), mainly due to SDH mutations. While SDHD mutations were found in all patients with familial head and neck paragangliomas, in sporadic cases, the prevalence of SDHB mutations (n = 8, 27%) was twice that of SDHD mutations (n = 4, 13%). Patients harbouring SDHB mutations had unilateral late-onset head and neck tumours without evidence of recurrence or malignancy. CONCLUSION: This Belgian series confirms the elevated prevalence of predisposing mutations in patients with head and neck and extra-adrenal paragangliomas, but differs from previous reports by the high frequency of SDHB mutations associated with head and neck paragangliomas without evidence of recurrence or malignancy