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Dive into the research topics where Valérie Detti is active.

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Featured researches published by Valérie Detti.


Ultrasound in Medicine and Biology | 2003

Visualisation of HIFU lesions using elastography of the human prostate in vivo: preliminary results

Rémi Souchon; Albert Gelet; Valérie Detti; S. Srinivasan; Jonathan Ophir; Jean-Yves Chapelon

An imaging system was developed for prostate elastography in vivo using a transrectal ultrasound (US) probe to guide high-intensity focused US (HIFU) therapy of prostate cancer. Uniform compression was applied using a balloon, while a sector image was acquired. Strain was calculated from the gradient of the displacements obtained from the ultrasonic signal using the cross-correlation technique. Elastograms were acquired on a total of 31 patients undergoing HIFU therapy for localised prostate cancer. For two patients, only part of the prostate was treated and posttherapy magnetic resonance imaging (MRI) confirmed the size and position of the HIFU lesions seen in the elastograms as low strain areas, with a strain contrast ratio between 1.6 and 3.2. The whole prostate was treated for the next 29 patients. After treatment, the whole prostate appeared to be stiff in the elastograms and a 40% to 60% (mean 50%) decrease in average strain was observed when compared to strains measured before HIFU application. Tumours identified by biopsies and sonograms could occasionally be seen in the preoperative elastograms. Decorrelation effects occurred mainly because of low sonographic signal-to-noise ratio (SNR) and of out-of-plane motion induced by respiration.


Magnetic Resonance in Medicine | 2011

Assessment of radiofrequency self‐heating around a metallic wire with MR T1‐based thermometry

Valérie Detti; Denis Grenier; Emmanuel Perrin; Olivier Beuf

Heat produced by a magnetic resonance (MR) imaging sequence in the vicinity of a conductive wire (pacemaker, electrodes, or catheter), is a subject of interest for the assessment of patient safety during imaging. For this purpose, the measurement of temperature rises during an MR imaging sequence using MR T1‐based thermometry provides several advantages, mainly in its ability to retrieve in situ real‐time thermal maps. Recent studies investigated the heat produced by an independent radiofrequency pulse, assessing MR imaging sequence heating using a specific MR thermometry sequence. This study focuses on self‐heating for which the radiofrequency pulses used for measuring temperature create the heat. An experimental design was set up to evaluate T1‐based thermometry self‐heating using a coupled/decoupled wire and to compare it with a reference temperature gathered by an optical fiber device. For the tested experimental set up, T1‐based thermometry is in fairly good agreement with optical fiber reference temperature. Magn Reson Med, 2011.


Ultrasound in Medicine and Biology | 2017

Specific Ultrasound Data Acquisition for Tissue Motion and Strain Estimation: Initial Results

Elisabeth Brusseau; Adeline Bernard; Cyril Meynier; Philippe Chaudet; Valérie Detti; Guillaume Ferin; Olivier Basset; An Nguyen-Dinh

Ultrasound applications such as elastography can benefit from 3-D data acquisition and processing. In this article, we describe a specific ultrasound probe, designed to acquire series of three adjacent imaging planes over time. This data acquisition makes it possible to consider the out-of-plane motion that can occur at the central plane during medium scanning, and is proposed with the aim of improving the results of strain imaging. In this first study, experiments were conducted on phantoms, and controlled axial and elevational displacements were applied to the probe using a motorized system. Radiofrequency ultrasound data were acquired at a 40-MHz sampling frequency with an Ultrasonix ultrasound scanner, and processed using a 3-D motion estimation method. For each of the 2-D regions of interest of the central plane in pre-compression data, a 3-D search was run to determine its corresponding version in post-compression data, with this search taking into account the region-of-interest deformation model chosen. The results obtained with the proposed ultrasound data acquisition and strain estimation were compared with results from a classic approach and illustrate the improvement produced by considering the mediums local displacements in elevation, with notably an increase in the mean correlation coefficients achieved.


Proceedings of SPIE | 2011

A two dimensional locally regularized strain estimation technique: preliminary clinical results for the assessment of benign and malignant breast lesions

Elisabeth Brusseau; Valérie Detti; Agnès Coulon; Emmanuèle Maissiat; Nawele Boublay; Yves Berthezène; Jérémie Fromageau; Nigel L. Bush; Jeffrey C. Bamber

We previously developed a 2D locally regularized strain estimation technique that was already validated with ex vivo tissues. In this study, our technique is assessed with in vivo data, by examining breast abnormalities in clinical conditions. Method reliability is analyzed as well as tissue strain fields according to the benign or malignant character of the lesion. Ultrasound RF data were acquired in two centers on ten lesions, five being classified as fibroadenomas, the other five being classified as malignant tumors, mainly ductal carcinomas from grades I to III. The estimation procedure we developed involves maximizing a similarity criterion (the normalized correlation coefficient or NCC) between pre- and post-compression images, the deformation effects being considered. The probability of correct strain estimation is higher if this coefficient is closer to 1. Results demonstrated the ability of our technique to provide good-quality strain images with clinical data. For all lesions, movies of tissue strain during compression were obtained, with strains that can reach 15%. The NCC averaged over each movie was computed, leading for the ten cases to a mean value of 0.93, a minimum value of 0.87 and a maximum value of 0.98. These high NCC values confirm the reliability of the strain estimation. Moreover, lesions were clearly identified for the ten cases investigated. Finally, we have observed with malignant lesions that compared to ultrasound data, strain images can put in relief a more important lesion size, and can help in evaluating the lesion invasive character.


international conference of the ieee engineering in medicine and biology society | 2007

Radiofrequency power deposition near metallic wires during MR imaging: feasibility study using T1-weighted thermal imaging

F. Oulmane; Valérie Detti; Denis Grenier; Emmanuel Perrin; Hervé Saint-Jalmes

The presence of metallic conductors (implants, wires or catheters) is prohibited in MR imaging for safety purpose with respect to radiofrequency (RF) power deposition caused by RF excitation Bl field. This work describes the use of Tl-weigthed MR imaging for estimating a thermal map around a metallic (copper) wire located in the center of a MR imaging unit during an imaging sequence. The experimental set up and the methodology used for capturing the elevation of temperature created by radiofrequency power deposition around the wire is presented. A proof of its efficiency to follow- up temperature elevation about 0,5degC in a milimetric region of interest (pixel size: 1 times 1 mm2, slice thickness 5 mm) located around the wire is given, leading to further developments of MR imaging in presence of metallic implants, coils or catheters.


Medical Imaging Based on Magnetic Fields and Ultrasounds | 2014

Ultrasound Medical Imaging

Didier Vray; Elisabeth Brusseau; Valérie Detti; François Varray; Adrian Basarab; Olivier Beuf; Olivier Basset; Christian Cachard; Hervé Liebgott; Philippe Delachartre


Ultrasound in Medicine and Biology | 2014

In Vivo Response to Compression of 35 Breast Lesions Observed with a Two-Dimensional Locally Regularized Strain Estimation Method

Elisabeth Brusseau; Valérie Detti; Agnès Coulon; Emmanuèle Maissiat; Nawele Boublay; Yves Berthezène; Jérémie Fromageau; Nigel L. Bush; Jeffrey C. Bamber


Recherche en Imagerie et Technologies pour la Santé (RITS) 2017 | 2017

MONTAGE EXPÉRIMENTAL BIOFIDÈLE D'AORTE ABDOMINALE

Vincent Perrot; Selina Meier; Aline Bel-Brunon; Hélène Walter-Le Berre; Benyebka Bou-Saïd; Philippe Chaudet; Valérie Detti; Didier Vray; Hervé Liebgott


Irbm | 2017

Biofidelic Abdominal Aorta Phantom: Cross-Over Preliminary Study Using UltraSound and Digital Image Stereo-Correlation

Vincent Perrot; S. Meier; A. Bel-Brunon; H. Walter-Le Berre; B. Bou-Saïd; Philippe Chaudet; Valérie Detti; Didier Vray; Hervé Liebgott


Archive | 2014

Imagerie médicale ultrasonore

Didier Vray; Elisabeth Brusseau; Valérie Detti; François Varray; Adrian Basarab; Olivier Beuf; Olivier Basset; Christian Cachard; Hervé Liebgott; Philippe Delachartre

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Jeffrey C. Bamber

The Royal Marsden NHS Foundation Trust

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Nigel L. Bush

Institute of Cancer Research

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