Search results for " mr"
showing 10 items of 495 documents
Water capillary absorption in porous media in different wettability conditions studied by Quantitative MRI and X-ray CT
2007
X-ray computed tomography (CT) and magnetic resonance imaging (MRI) have been successfully applied to study both the capillary properties of several samples of Lecce stone and the performances of treatments used for protection and conservation of historical stone artifacts. The presence of water inside the sample may be visualized by both MRI and X-ray CT. For the treated samples, the different dynamics of water absorption gives indirectly the efficacy of the polymer in the rock.
Study of optical absorbance and MR relaxation of Fricke xylenol orange gel dosimeters
2017
Abstract Studies on the optical absorbance spectra of Fricke xylenol orange gel dosimeters were performed, in the wavelength range from 300 nm to 800 nm, in order to highlight some particular characteristics that can affect the achievable precision. The spectra are different mainly due to the different types of xylenol orange that was used and to a lower extent due to the different gelling agents (agarose or gelatine). The characteristic of variation of absorbance spectra versus dose, however, are similar in the various cases and can explain some peculiarities, as apparent effects of dose threshold. Changes of spectral shapes appear over the time after irradiation. Magnetic resonance measur…
Definition of a mutual reference shape based on information theory and active contours
2013
In this paper, we propose to consider the estimation of a reference shape from a set of different segmentation results using both active contours and information theory. The reference shape is then defined as the minimum of a criterion that benefits from both the mutual information and the joint entropy of the input segmentations. This energy criterion is here justified using similarities between information theory quantities and area measures, and presented in a continuous variational framework. This framework brings out some interesting evaluation measures such as the specificity and sensitivity. In order to solve this shape optimization problem, shape derivatives are computed for each te…
Leveraging Uncertainty Estimates to Improve Segmentation Performance in Cardiac MR
2021
International audience; In medical image segmentation, several studies have used Bayesian neural networks to segment and quantify the uncertainty of the images. These studies show that there might be an increased epistemic uncertainty in areas where there are semantically and visually challenging pixels. The uncertain areas of the image can be of a great interest as they can possibly indicate the regions of incorrect segmentation. To leverage the uncertainty information, we propose a segmentation model that incorporates the uncertainty into its learning process. Firstly, we generate the uncertainty estimate (sample variance) using Monte-Carlo dropout during training. Then we incorporate it …
Using Polynomial Loss and Uncertainty Information for Robust Left Atrial and Scar Quantification and Segmentation
2022
Automatic and accurate segmentation of the left atrial (LA) cavity and scar can be helpful for the diagnosis and prognosis of patients with atrial fibrillation. However, automating the segmentation can be difficult due to the poor image quality, variable LA shapes, and small discrete regions of LA scars. In this paper, we proposed a fully-automatic method to segment LA cavity and scar from Late Gadolinium Enhancement (LGE) MRIs. For the loss functions, we propose two different losses for each task. To enhance the segmentation of LA cavity from the multicenter dataset, we present a hybrid loss that leverages Dice loss with a polynomial version of cross-entropy loss (PolyCE). We also utilize …
The distribution of sodium within cooked food and sodium interactions with the matrix depends on both food matrices and salting practices
2021
The quantitative maps results show that the sodium distribution is more heterogeneous in the carrot salted after cooking than in the carrot salted during cooking The salt diffusion during 5 hours after the 20 minutes of cooking for cooked carrot either salted during cooking or salted after cooking show an homogenization of the sodium
La croyance dans le fumoir : “The Portrait of Mr. WH”, l’éthique de la croyance de William Kingdon Clifford et l’assentiment selon John Henry Newman
2023
Wilde’s story “The Portrait of Mr. W.H.” blurs literary genres, asserts the importance of the false and plays with reader expectations. It has generated a substantial exege- sis, perhaps lacking in interest in the multi-faceted debates on belief running through the 1870s-1880s. Wilde takes part in that debate through a text of uncertain status and complex editorial history, contrasting Newmanian assent with W.K. Clifford’s ethics of belief (1877), before asserting the supremacy of desire, thus ruining all assent and epistemically justified belief. To the demanding philosophical-religious theories of Clifford and Newman, Wilde responds with an ambiguous, subversive narrative, intended to com…
Expression of inflammation-related genes in human atherosclerotic plaques
2010
Aims: Atherosclerosis is an inflammator y disease which molecular mechanisms are not been completely investigated. Our aim is to perform a wide expression study of inflammation related genes in human atherosclerotic plaques. Methods: The Human Inflammation Array (Applied Biosystems) was used to perform the mRNA quantification of 92 inflammation-related genes in 12 atherosclerotic plaques, their respective adjacent regions (with a lower grade lesion) and 7 healthy ar teries. The principle of the array is the real-time PCR amplification with a TaqMan probe specific for each gene. Data analysis was performed with SDS 2.3 software with the comparative Ct method using the gene beta-2-microglobulin as h…
Medication-Related Osteonecrosis of Jaws (MRONJ) Prevention and Diagnosis: Italian Consensus Update 2020
2020
The Medication-Related Osteonecrosis of Jaws (MRONJ) diagnosis process and its prevention play a role of great and rising importance, not only on the Quality of Life (QoL) of patients, but also on the decision-making process by the majority of dentists and oral surgeons involved in MRONJ prevention (primary and secondary). The present paper reports the update of the conclusions from the Consensus Conference—held at the Symposium of the Italian Society of Oral Pathology and Medicine (SIPMO) (20 October 2018, Ancona, Italy)—after the newest recommendations (2020) on MRONJ were published by two scientific societies (Italian Societies of Maxillofacial Surgery and Oral Pathology and Medicine, SI…
Automatic multi-seed detection for MR breast image segmentation
2017
In this paper an automatic multi-seed detection method for magnetic resonance (MR) breast image segmentation is presented. The proposed method consists of three steps: (1) pre-processing step to locate three regions of interest (axillary and sternal regions); (2) processing step to detect maximum concavity points for each region of interest; (3) breast image segmentation step. Traditional manual segmentation methods require radiological expertise and they usually are very tiring and time-consuming. The approach is fast because the multi-seed detection is based on geometric properties of the ROI. When the maximum concavity points of the breast regions have been detected, region growing and m…