Laurence Gavit

Le procede de detection automatique du mouvement cardiaque destine a etre mis en oeuvre au sein d'un dispositif de radiographie (1) comporte des etapes de :a) acquisition par les moyens d'enregistrement d'une serie d'images successives In de la region du coeurb) analyse d'au moins une partie des images ainsi acquises pour y mettre en evidence un mouvement du coeur, etc) determination du cycle cardiaque a partir de ce mouvement.

L'invention concerne un procede d'acquisition d'une image radiologique tridimensionnelle d'un organe en mouvement d'un patient, selon lequel une unite de commande execute des etapes de :- (53, 54) recevoir un signal representatif d'un parametre de mouvement de l'organe,- (53, 54) detecter une variation du signal due a un maintien artificiel de l'organe dans un etat de mouvement reduit, et- en reponse a la detection, (59, 510) declencher une acquisition d'une sequence d'images par un dispositif d'imagerie radiologique en vue de reconstruire une image radiologique tridimensionnelle de l'organe a partir de la sequence d'images.

The present invention relates to a method for detecting and clearing the breathing movement. This detection improves the registration between a three-dimensional pre-operative image and images X-ray acquired during cardiac surgery. By synchronizing the X-ray images on the electrocardiogram, the invention thus eliminates these images the movement related to the cardiac cycle, allowing to isolate the contribution of respiratory movement. From there, the invention provides a fit to assign the movement left in the radiographic images to breathing algorithm. The algorithm can also detect and compensate for this movement to obtain a registration between three-dimensional cardiac images and radiographic images

L'invention concerne un ensemble d'imagerie medicale comprenant un capteur de rayonnement (250), un support (200) de ce capteur, une table de support de patient (100) ainsi que des moyens de deplacement relatifs de la table (100) et du support (200), le dispositif comprenant en outre des moyens de traitement de donnees aptes a determiner, a partir d'une indication de positionnement d'une region d'interet (350) par le praticien, un deplacement relatif table/capteur afin que la region d'interet (350) se trouve au centre (450) du faisceau d'acquisition (400), caracterise en ce que les moyens de traitement sont prevus pour prendre en compte, a partir d'une prise de vue, une droite geometrique (450) passant par la region d'interet (350) et pour prendre en compte une autre entite geometrique (455, 800) passant par la region d'interet (350), puis determiner en trois dimensions la position d'une intersection de cette droite (450) et de cette autre...

ABSTRACT Discordance between lesion severity from angiocardiography and physiological effects has been reported elsewhere. Quantification of myocardial perfusion during the angiography procedure may supply additional information about short- and long-term outcomes and may be helpful for clinical decision making. In previous works, myocardial perfusion has been assessed using time density curves (TDC), which represent the contrast medium dilution over time in the myocardium. The mean transit time (MTT), derived from the TDC, has been reported as a good indicator of the regional myocardial perfusion. Our objective is to estimate the accuracy and reproducibility of MTT estimation on digital flat panel (DFP) images. We have simulated typical myocardium TDC obtained with a DFP cardiac system (Innova 2000, GE), taking into account scatter and noise. Logarithmic or linear subtractions have been applied to derive a contrast medium concentration proportional quantity from image intensity. A non-linear minimisation realises the model curve fitting. MTT estimates are more stable with linear subtraction in presence of scatter. However logarithmic subtraction presents smaller bias when scatter level is small. Both approaches are equally sensible to image noise. Linear subtraction should be preferred. Image noise has a high influence on MTT accuracy and we may reduce.

On images acquired with a digital flat‐panel (DFP) detector, known for its better image quality, the performance of a validated quantitative coronary arteriography (QCA) software, CAASII (Cardiovascular Angiography Analysis System or CAAS), and a DFP‐dedicated QCA algorithm (flat‐panel analysis software or FPAS) was compared in a phantom and a patient study. On phantom, FPAS performed with higher accuracy the quantification of the smallest tubes and the calibration of an empty catheter. The overall accuracy and precision for the quantification procedure was better for FPAS (0.07 ± 0.04 mm) than for the CAAS (0.19 ± 0.06 mm; P = 0.03 and P < 0.01, respectively). In the patient study, the main difference between the two algorithms was found in the small diameters: CAAS almost always gave higher values than FPAS for the minimal luminal diameter (P < 0.001) and could only give values up to 70% for diameter stenosis. In conclusion, the FPAS can be considered more appropriate for as...

IntroductionThe inverse problem consisting in extracting a sourcemap from MEG data is well known to be ill-posed,having no unique solution and being numerically instable.Moreover, in the distributed source model,first introduced by Hmlinen et al [1], thousands ofsources are to be reconstructed from only about 200simultaneous data samples.To solve this problem, a first approach consists in iterativelyreducing the search space around

Percutaneous transluminal coronary angioplasty consists in conducting a balloon and a stent through a coronary lesion and deploying the stent by balloon inflation. A coronary stent is a 3D complex mesh hardly visible in X-Ray images. The control of stent deployment is difficult from the 2D projection images inspection although insufficient deployment of the stent may lead to post intervention complications. In previous works, we have proposed a way to improve the clinical control of the intervention in the continuity of the angiographic procedure. We suggest to reconstruct 3D stent images from a set of 2D cone-beam projections acquired in rotational acquisition mode, using a motion compensation technique. In this paper, we investigate the feasibility of this method on coronary stents in-vivo. We first introduce one synthetic realistic case to illustrate the incorrect deployment problematic and control requirements. In-vivo experiments have been carried out on ten pigs, the porcine m...