Philippe Raffy

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OBJECTIVE The purpose of this article is to assess detection, tracking, and reading time of solid lung nodules > or = 4 mm on pairs of MDCT chest screening examinations using a computer-aided detection (CAD) system. MATERIALS AND METHODS Of 54 pairs of low-dose MDCT chest examinations (1.25-mm collimation), two chest radiologists in consensus established(More)
The increasing demand for real-time applications requires the use of variable-rate quantizers having good performance in the low bit rate domain. In order to minimize the complexity of quantization, as well as maintaining a reasonably high PSNR ratio, we propose to use an entropy-coded lattice vector quantizer (ECLVQ). These quantizers have proven to(More)
OBJECTIVES Evaluate the improvement in detecting lung nodules when using multidetector CT (MDCT) computer-assisted diagnosis (CAD). MATERIAL AND METHODS Three radiologists (R1, R2, R3) with different levels of experience independently interpreted 30 MDCT examinations of the thorax taken for screening purposes, first without and then with CAD. The(More)
RATIONALE Chartis Pulmonary Assessment System (Pulmonx Inc., Redwood, CA) is an invasive procedure used to assess collateral ventilation and select candidates for valve-based lung volume reduction (LVR) therapy. Quantitative computed tomography (QCT) is a potential alternative to Chartis and today consists primarily of assessing fissure integrity (FI). (More)
BACKGROUND Although lobar patterns of emphysema heterogeneity are indicative of optimal target sites for lung volume reduction (LVR) strategies, the presence of segmental, or sublobar, heterogeneity is often underappreciated. OBJECTIVE The aim of this study was to understand lobar and segmental patterns of emphysema heterogeneity, which may more precisely(More)
We propose an object-tracking algorithm that predicts the object contour using motion vector information. Tracking is achieved by predicting the object boundary using motion vectors, followed by contour update, using occlusions/disocclusion detection. An adaptive block-based approach has been used for estimating motion between frames. An efficient(More)
We propose a multiresolution algorithm to jointly optimize a source coder and channel coder. The variable-rate source coder combines an optimal bit-allocation strategy and efficient stack-run coding. This compression scheme, concatenated with appropriate rate-compatible punctured convolutional codes, provides a competitive approach to state-of-the-art(More)
A tracking algorithm that predicts the object contour using motion vector information is proposed in this paper. Tracking is achieved by predicting the object boundary using motion vectors, followed by contour update, using occlusionsldisocclusion detection. An adaptive block-based approach has been used for estimating motion between frames. An efficient(More)
RATIONALE AND OBJECTIVES To assess the effect of three-dimensional (3D) lossy image compression of multidetector computed tomography chest scans on computer-aided detection (CAD) of solid lung nodules greater than 4 mm in size. MATERIALS AND METHODS A total of 120 cases, acquired with 1.25-mm collimation, were collected from 5 different sites, of which(More)