Search results for "Bioengineering"
showing 10 items of 1963 documents
Contrast Preparation Pulses Robust to B1 and B0 inhomogeneities: an Optimal Control Approach
2018
International audience
Texture analysis of tumour metabolism and perfusion for newly diagnosed breast cancer using dynamic first-pass 18F-FDG PET/CT
2018
International audience
Tomographies Optiques et NeuroImageries Rhône-alpines chez le petit animal
2009
International audience
Tomographies Optique Diffuse spectrale et spatiale: réponse hémodynamique cérébrale à une stimulation acoustique chez le diamant mandarin
2009
International audience
Improved estimation of the left ventricular ejection fraction using a combination of independent automated segmentation results in cardiovascular mag…
2014
—This work aimed at combining different segmenta-tion approaches to produce a robust and accurate segmentation result. Three to five segmentation results of the left ventricle were combined using the STAPLE algorithm and the reliability of the resulting segmentation was evaluated in comparison with the result of each individual segmentation method. This comparison was performed using a supervised approach based on a reference method. Then, we used an unsupervised statistical evaluation, the extended Regression Without Truth (eRWT) that ranks different methods according to their accuracy in estimating a specific biomarker in a population. The segmentation accuracy was evaluated by focusing o…
Analysis of fluorescent MRI contrast agent behavior in the liver and thoracic aorta of mice.
2004
To characterize the behavior of magnetofluorescent products injected in mice intravenously.The magnetic resonance imaging (MRI) products were labelled with fluorescent molecules to examine the biodistribution process in vivo and observe them at the cellular level by means of confocal microscopy. Three-dimensional (3D) sequences of images were obtained by spectral analysis of sample preparations in a multiphoton confocal microscope and analyzed by the factor analysis of medical image sequence algorithm, which provides factor curves. Factor images are the result of image-processing methods that utilize information from emission spectra. Preparations are also screened in the counting mode to p…
Hypofractionnated radiotherapy for elderly patients with prostate cancer
2018
Radiation therapy technique and schedules could be adapted to patient's age because of a natural history of prostate cancer perceived as different, taking into account the comorbidities of patients but also a particular tolerance of elderly subjects. Thus, in localized prostate cancer, evaluation of associated diseases is essential before considering a treatment that will be of interest only if the life expectancy is greater than 10 years. When a curative approach is decided, radiotherapy holds a place of choice. Due to the recent results of randomized studies evaluating moderate hypofractionnated radiotherapy, showing a carcinological equivalence compared to a standard fractionation, this …
Left-Ventricle Segmentation of SPECT Images of Rats
2015
Single-photon emission computed tomography (SPECT) imaging of the heart is helpful to quantify the left-ventricular ejection fraction and study myocardial perfusion scans. However, these evaluations require a 3-D segmentation of the left-ventricular wall on each phase of the cardiac cycle. This paper presents a fast and interactive graph cut method for 3-D segmentation of the left ventricle (LV) of rats in SPECT images. The method is carried out in three steps. First, 3-D sampling of the LV cavity is made in a spherical-cylindrical coordinate system. Then, a graph-cut-based energy minimization procedure provides delineation of the myocardium centerline surface. From there, it is possible to…
Redshifted Cherenkov Radiation for in vivo Imaging: Coupling Cherenkov Radiation Energy Transfer to multiple Förster Resonance Energy Transfers
2017
AbstractCherenkov Radiation (CR), this blue glow seen in nuclear reactors, is an optical light originating from energetic β-emitter radionuclides. CR emitter 90Y triggers a cascade of energy transfers in the presence of a mixed population of fluorophores (which each other match their respective absorption and emission maxima): Cherenkov Radiation Energy Transfer (CRET) first, followed by multiple Förster Resonance Energy transfers (FRET): CRET ratios were calculated to give a rough estimate of the transfer efficiency. While CR is blue-weighted (300–500 nm), such cascades of Energy Transfers allowed to get a) fluorescence emission up to 710 nm, which is beyond the main CR window and within t…
Modular Assembly of Multimodal Imaging Agents through an Inverse Electron Demand Diels–Alder Reaction
2019
International audience; The combination of two imaging probes on a same biomolecule gives access to targeted bimodal imaging agents that can provide more accurate diagnosis, complementary information, or that may be used in different applications, such as PET imaging and fluorescence imagingassisted surgery. In this study, we demonstrate that dichlorotetrazine, a small, commercially available compound, can be used as a modular platform to easily assemble various imaging probes. Doubly-labeled tetrazines can then be conjugated to a protein through a biorthogonal IEDDA reaction. A series of difunctionalized tetrazine compounds containing various chelating agents and fluorescent dyes was synth…