Frédéric Courivaud

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Assessment of vascular properties is essential to diagnosis and follow-up and basic understanding of pathogenesis in brain tumors. In this study, a procedure is presented that allows concurrent estimation of cerebral perfusion, blood volume, and blood-brain permeability from dynamic T(1)-weighted imaging of a bolus of a paramagnetic contrast agent passing(More)
BACKGROUND Axillary block is the most commonly performed brachial plexus block and may be guided by nerve stimulation or ultrasound. Magnetic resonance imaging (MRI) has proven to be beneficial in presenting anatomy of interest for regional anaesthesia and in demonstrating spread of local anaesthetic. The aim of this pilot study was to demonstrate the(More)
PURPOSE To present an automated algorithm for segmentation of visceral, subcutaneous, and total volumes of adipose tissue depots (VAT, SAT, TAT) from whole-body MRI data sets and to investigate the VAT segmentation accuracy and the reproducibility of all depot assessments. MATERIALS AND METHODS Repeated measurements were performed on 24 volunteer subjects(More)
Quantification of intramyocellular lipids (IMCL) in obese subjects by single-voxel spectroscopy (SVS) or conventional spectroscopic imaging (SI) often fails due to overlap of IMCL spectral lines by extramyocellular lipids (EMCL), and signal contamination from subcutaneous fat and bone marrow. This study demonstrates that these problems can be solved by(More)
Anatomical standardization (also called spatial normalization) of positron emission tomography (PET) small animal brain images is required to make statistical comparisons across individuals. Frequently, PET images are co-registered to an individual MR or CT image of the same subject in order to transform the functional images to an anatomical space. In the(More)
Our purpose was to compare the quality of ureteral imaging in pediatric patients using two different MR sequences: the non-enhanced heavily T2-weighted (W) turbo spin-echo sequence (TSE) and the gadolinium-enhanced T1W fast-field-echo sequence (T1 FFE). An experimental study on three pigs was first performed. The TSE, before and after furosemide injection,(More)
This paper presents and evaluates stochastic computer algorithms used to automatically detect and track marked catheter tip during MR-guided catheterization. The algorithms developed employ extraction and matching of regional features of the catheter tip to perform the localization. To perform the tracking, a probability map that indicates the possible(More)
INTRODUCTION The purpose of this study was to evaluate the feasibility and safety of the Sonalleve high-intensity focused ultrasound (HIFU; Philips Healthcare, Vantaa, Finland) system in ablating uterine fibroids in a 3T magnet. MATERIAL AND METHODS Seven women were included in this study. Treatment was performed according to the manufacturer's(More)
A novel spectroscopic imaging method with high spectral and spatial resolution was developed for the specific goal of assessing muscle fat. Sensitivity to the methylene and methyl protons of fatty acids was improved by the use of a binomial 1 1 excitation pulse instead of the standard radiofrequency (RF) pulse. Acceptable measurement time is achieved by(More)
BACKGROUND Axillary plexus blocks are usually guided by ultrasound, but alternative methods may be used when ultrasound equipment is lacking. For a nonultrasound-guided axillary block, the need for three injections has been questioned. OBJECTIVES Could differences in block success between single, double and triple deposits methods be explained by(More)