Investigating the performance of generative adversarial networks for prostate tissue detection and segmentation

The manual delineation of region of interest (RoI) in 3D magnetic resonance imaging (MRI) of the prostate is time-consuming and subjective. Correct identification of prostate tissue is helpful to define a precise RoI to be used in CAD systems in clinical practice during diagnostic imaging, radiotherapy and monitoring the progress of disease. Conditional GAN (cGAN), cycleGAN and U-Net models and their performances were studied for the detection and segmentation of prostate tissue in 3D multi-parametric MRI scans. These models were trained and evaluated on MRI data from 40 patients with biopsy-proven prostate cancer. Due to the limited amount of available training data, three augmentation schemes were proposed to artificially increase the training samples. These models were tested on a clinical dataset annotated for this study and on a public dataset (PROMISE12). The cGAN model outperformed the U-Net and cycleGAN predictions owing to the inclusion of paired image supervision. Based on our quantitative results, cGAN gained a Dice score of 0.78 and 0.75 on the private and the PROMISE12 public datasets, respectively

Modèles stochastiques pour l'évaluation de politiques de maintenance sur des systèmes à dégradation graduelle

TROYES-SCD-UTT (103872102) / SudocSudocFranceF

Assessment of a maintenance model for a multi-deteriorating mode system

International audienceThis paper deals with maintenance policies for stochastically deteriorating systems which are subject to sudden changes in their degradation processes. The main aim is to assess the interest of using change mode monitoring information from a maintenance decision making point of view. Two condition-based maintenance policies are considered and compared, each of them adapted to a specific level of available information, with or without change mode monitoring.Numerical examples show that the time distribution of the change of deterioration rate and the difference between the two possible deterioration rates strongly influence the choice of the best decision rule structure

Assessment of an imperfect maintenance policy on a finite time span

International audienc

Maintenance policy on a finite time span for a gradually deteriorating system with imperfect improvements

International audienceThe study deals with a gradually deteriorating system such as a large structure. This system is studied over a finite time span where the finite horizon can be seen, for example, as an insurance deadline which requires a specific maintenance policy. Maintenance actions are assumed to be imperfect in this work. An improvement function is used to model the impact of the maintenance on the degradation level of the system. The improvement function is based in the virtual age model ARA1. A maintenance policy is then proposed in which maintenance actions are systematically performed at given maintenance dates, if the system has not already failed. It is assumed that in the event of a failure the system is not repaired. The system is then unavailable until the finite horizon. The proposed maintenance policy is assessed on the finite time span, and both maintenance dates and the number of maintenance actions are optimized

Assessment of a control limit maintenance decision rule for a multi deteriorating mode system

International audienc

Maintenance Conditionnelle en-ligne de systèmes à plusieurs modes de dégradation

International audienc

Imperfect condition-based maintenance on a finite time span for a gradually deteriorating system

International audienc

Transient Receptor Potential Canonical 3 (TRPC3) Channels Are Required for Hypothalamic Glucose Detection and Energy Homeostasis

International audienceThe mediobasal hypothalamus (MBH) contains neurons capable of directly detecting metabolic signals such as glucose to control energy homeostasis. Among them, glucose-excited (GE) neurons increase their electrical activity when glucose rises. In view of previous work, we hypothesized that transient receptor potential canonical type 3 (TRPC3) channels are involved in hypothalamic glucose detection and the control of energy homeostasis. To investigate the role of TRPC3, we used constitutive and conditional TRPC3-deficient mouse models. Hypothalamic glucose detection was studied in vivo by measuring food intake and insulin secretion in response to increased brain glucose level. The role of TRPC3 in GE neuron response to glucose was studied by using in vitro calcium imaging on freshly dissociated MBH neurons. We found that whole body and MBH TRPC3-deficient mice have increased body weight and food intake. The anorectic effect of intracerebroventricular glucose and the insulin secretory response to intracarotid glucose injection are blunted in TRPC3-deficient mice. TRPC3 loss of function or pharmacological inhibition blunts calcium responses to glucose in MBH neurons in vitro. Together, the results demonstrate that TRPC3 channels are required for the response to glucose of MBH GE neurons and the central effect of glucose on insulin secretion and food intake