Towards a diffusion image processing validation and accuracy prediction framework

Validation is the main bottleneck preventing theadoption of many medical image processing algorithms inthe clinical practice. In the classical approach,a-posteriori analysis is performed based on someobjective metrics. In this work, a different approachbased on Petri Nets (PN) is proposed. The basic ideaconsists in predicting the accuracy that will result froma given processing based on the characterization of thesources of inaccuracy of the system. Here we propose aproof of concept in the scenario of a diffusion imaginganalysis pipeline. A PN is built after the detection ofthe possible sources of inaccuracy. By integrating thefirst qualitative insights based on the PN withquantitative measures, it is possible to optimize the PNitself, to predict the inaccuracy of the system in adifferent setting. Results show that the proposed modelprovides a good prediction performance and suggests theoptimal processing approach.

Multi-source composite kernels for urban image classification

This letter presents advanced classification methods for very high resolution images. Efficient multisource information, both spectral and spatial, is exploited through the use of composite kernels in support vector machines. Weighted summations of kernels accounting for separate sources of spectral and spatial information are analyzed and compared to classical approaches such as pure spectral classification or stacked approaches using all the features in a single vector. Model selection problems are addressed, as well as the importance of the different kernels in the weighted summation.

Image quality assessment in digital mammography: part II. NPWE as a validated alternative for contrast detail analysis.

Assessment of image quality for digital x-ray mammography systems used in European screening programs relies mainly on contrast-detail CDMAM phantom scoring and requires the acquisition and analysis of many images in order to reduce variability in threshold detectability. Part II of this study proposes an alternative method based on the detectability index (d') calculated for a non-prewhitened model observer with an eye filter (NPWE). The detectability index was calculated from the normalized noise power spectrum and image contrast, both measured from an image of a 5 cm poly(methyl methacrylate) phantom containing a 0.2 mm thick aluminium square, and the pre-sampling modulation transfer function. This was performed as a function of air kerma at the detector for 11 different digital mammography systems. These calculated d' values were compared against threshold gold thickness (T) results measured with the CDMAM test object and against derived theoretical relationships. A simple relationship was found between T and d', as a function of detector air kerma; a linear relationship was found between d' and contrast-to-noise ratio. The values of threshold thickness used to specify acceptable performance in the European Guidelines for 0.10 and 0.25 mm diameter discs were equivalent to threshold calculated detectability indices of 1.05 and 6.30, respectively. The NPWE method is a validated alternative to CDMAM scoring for use in the image quality specification, quality control and optimization of digital x-ray systems for screening mammography.

Corruption in building the image of politics in television news broadcasts

This work analyses the political news of eight Spanish television channels in order to see what image is built of politics, and particularly how the news of corruption affects the image of politics in Spanish news broadcasts. Different cases of corruption such as Gürtel, Palma Arena and those associated with judge Baltasar Garzón in his final stage in office, occupy part of the study. A new methodology is therefore proposed that enables the quality of the political information emitted from inside and outside the political content of the news programmes to be observed. Particular attention is paid to the news broadcasts of Televisión Española and Cuatro as those which offer a more balanced view of politics, and channels such as La Sexta, which give priority to a narrative construction of politics in the news programmes around causes of corruption.

Free-breathing whole-heart coronary MRA with 3D radial SSFP and self-navigated image reconstruction.

Respiratory motion is a major source of artifacts in cardiac magnetic resonance imaging (MRI). Free-breathing techniques with pencil-beam navigators efficiently suppress respiratory motion and minimize the need for patient cooperation. However, the correlation between the measured navigator position and the actual position of the heart may be adversely affected by hysteretic effects, navigator position, and temporal delays between the navigators and the image acquisition. In addition, irregular breathing patterns during navigator-gated scanning may result in low scan efficiency and prolonged scan time. The purpose of this study was to develop and implement a self-navigated, free-breathing, whole-heart 3D coronary MRI technique that would overcome these shortcomings and improve the ease-of-use of coronary MRI. A signal synchronous with respiration was extracted directly from the echoes acquired for imaging, and the motion information was used for retrospective, rigid-body, through-plane motion correction. The images obtained from the self-navigated reconstruction were compared with the results from conventional, prospective, pencil-beam navigator tracking. Image quality was improved in phantom studies using self-navigation, while equivalent results were obtained with both techniques in preliminary in vivo studies.

Le Linceul: une exploration par la bande dessinée des potentialités narratives de la (re)production de l'image christique

L'article aborde la façon dont la série BD Le Linceul (2003-2006) s'approprie, dans le cadre de la fiction et du récit d'action grand public, le contexte de la réception de l'image acheiropoïète du Saint Suaire, intégrant la référence à des enjeux théologiques et scientifiques au sein d'une histoire à suspense située à différentes époques et dont les nombreux rebondissements s'articulent autour d'une croyance progressive dans le statut sacré de la vera icon. L'examen détaillé de certains choix narratifs et graphiques de l'auteur Laurent Bidot permet de dégager les modalités d'une exploitation contemporaine et (a priori) laïcisée de la figure de Jésus qui, à l'ère des technologies numériques, conserve sa part de mystère. Dans une perspective narratologique, l'interprétation procède principalement de constats liés à l'organisation énonciative de cette production bédéique.

Image Analysis for the Characterization of Materials for Highway Construction : Phase I, Progress Report, HR-346, 1992

The major objective of this project is to evaluate image analysis for characterizing air voids in Portland cement contract (PCC) and asphalt concrete (AC) and aggregate gradation in asphalt concrete. Phase 1 of this project has concentrated on evaluation and refinement of sample preparation techniques, evaluation of methods and instruments for conducting image analysis, and finally, analysis and comparison of a select portion of samples. Preliminary results suggest a strong correlation between the results obtained from the linear traverse method and image analysis methods for determining percent air voids in concrete. Preliminary work with asphalt samples has shown that damage caused by a high vacuum of the conventional scanning electron microscope (SEM) may too disruptive. Alternative solutions have been explored, including confocal microscopy and low vacuum electron microscopy. Additionally, a conventional high vacuum SEM operating at a marginal operating vacuum may suffice.

Le Roman de Renart

F. 1-48. Le Roman de Renart. Le manuscrit, qui a été doté du sigle O dans les différentes éditions, est incomplet de la fin et mixte, proposant une structure relativement inédite. Il a récemment fait l’objet d’une édition critique par Aurélie Barre : Édition critique et littéraire du manuscrit O du « Roman de Renart » ( f. fr. 12583), doctorat, Université Lyon III, 2005. F. 1a-14b. Branche I.F. 1a-7e. [Branche Ia : « Le jugement de Renart »]. « Pierres qui son enging et s’art / Mist es vers faire de Renart…-… Tant qu’il [re]fu en sa santé / Com il avoit devant esté ». – F. 7e-10b. [Branche Ib : « Le Siège de Maupertuis »]. « Messires Nobles l’empereres / Vint au chastel ou Renart ere …-… Et Renart ainsi s’en eschape, / Des or gart bien chascun sa chape ! ». – F. 10b-14b. [Branche Ic : « Renart teinturier, Renart jongleur »]. « Li rois a fait son ban crier, / Par tout plevir et afier …-… Puis fu Renart lonc tens en mue ; / Ne va, ne vient, ne se remue » (éd. Barre, p.117-233, v. 1-3217). . F. 14b-20bBranche II. F. 14b-20b. [Branche II : « Le duel judiciaire »]. « Messires Nobles li lions / O lui avoit toz ses barons …-… Et autre redirai aprés, / A itant de cestui vos lés » (éd. Barre, p. 235-289, v. 1-1522). F. 20b-25c. Branche III.F. 20b-22a. [Branche IIIa : « Renart et Chantecler »]. « Seignors, oï avez maint conte, / Que maint contierres vos aconte …-… Dou coc qui li est eschapez, / Quant il ne s’en est saoulez ». – F. 22a-22f. [Branche IIIb : « Renart et la mésange »]. « Que que cil se plaint et demente, / Atant es vos une mesenge …-… Assez a grant travail eü / de ce dont li est mescheü ». – F. 22f-23c. [Branche IIIc. « Renart et Tibert »]. « Que qu’il se plaint de s’aventure, / Qui li avient et pesme et dure …-… Tornez s’en est a mout grant paine …-… Si com aventure le maine ». – F. 23c-24e. [Branche IIId : « Renart et l’andouille »]. «Renart qui mout sot de treslüe, / Et qui mout ot grant fain eüe …-… Esfondree ert entr’eus la guerre, / Mes ne velt trive ne pes querre ». – F. 24e-25c. [Branche IIIe : « Tibert et les deux prêtres »]. « Thibert li chaz, dont je a dit, / Doute Renart assez petit …-… Qui touz nos a enfantosmez : / A paine en sui vis eschapez ! » (éd. Barre, p. 291-340, v. 1-1265). F. 25c-27d. Branche IV. F. 25c-26a. [Branche IVa : « Renart et Tiercelin »]. « Entre .II. mons, en une plangne / Tout droit au pié d’une montaigne …-… Fuiant s’en va les sauz menuz : / Ses anemis a confonduz ». – F. 26a-27d. [Branche IVb : « Le viol d’Hersent »]. « Cis plaiz fu ainsi deffinez / Et Renars s’est acheminez …-… Et est venuz a sa mesnie / Qui soz la roche est entasnie » (éd. Barre, p. 341-359, v. 1-524). F. 27d-29d. Branche V. [« Renart et les anguilles »]. « Seignors, ce fu en cest termine / Que li douz tens d’esté decline …-…Que de Renart se vengera / Ne jamés jor ne l’amera » (éd. Barre, p. 361-378, v. 1-514). F. 29d-31e. Branche VI. [« Le puits »]. « Prime covient tel chose dire / Dont je vos puisse faire rire …-… Et il le puet prandre en sa marge, / Sachiez qu’i li fera domage ! » (éd. Barre, p. 379-396, v. 1-537).. 31e-39c. Branche VII. F. 31e-32e. [Branche VIIa : « Le jambon enlevé »]. « [U]n jour issit hors de la lande / Isengrins por querre viande …-… .XV. jours va a grant baudour, / Onques Renars n’i fist sejour ». – F. 32c-32e. [Branche VIIb : « Renart et le grillon »]. « Renart s’en va tout son chemin. / Or veut (en) engignier Isengrin …-… Tornez s’en est grant aleüre / Et vet aillors querre droiture ». – F. 32e-36e. [Branche VIIc : « L’Escondit »]. « Atant s’apense d’une chose / Dont il sa fame sovent chose …-…Tant defoulé et tant batu / Qu’a Malpertuis l’ont enbatu ». – F. 36e-39c. [Branche VIId : « La confession de Renart »]. « Foux est qui croit sa male pense : / Mout remaint de ce que fox panse …-…L’escofle lor donne a mengier, / Qu’il en avoient grant mestier (éd. Barre, p. 397-470, v. 1-1960). F. 36c-48e. Branche VIII. [« Renart et Liétart »]. « Uns prestres de la Croiz en Brie, / Que Damediex doint bone vie …-… Ou au chiés ou a la parclose, / Qui n’est aüsés de la chose » (éd. Barre, p. 471-554, v. 1-2470). F. 48e. Branche IX (v. 1-86). [« Les Vêpres de Tibert »]. « Oiez une novele estoire / Qui bien doit estre en mémoire …-… Jel conterai a Hameline, / La foi et la reconnoissance… » (éd. Barre, p. 555-557, v. 1-85).

Brain dysfunctions, psychopathologies, and body image distortions

The major features in eating disorders are a preoccupation with food and its consumption and body dissatisfaction. Diagnostic manuals provide clusters of criteria according to which affected individuals can be categorized into one or other group of eating disorder. Yet, when considering the high proportion of comorbidities and ignoring the content of the symptoms (food, body), the major features seem to yield obsessional-compulsive, addictive, and impulsive qualities. In the present article, we review studies from the neuroscientific literature (mainly lesion studies) on eating disorder, obsessive-compulsive disorder, impulse control disorder, and addiction to investigate the possibility of a wider phenotype that can be related to a common brain network. The literature localizes this network to the right frontal lobe and its connectivities. This network, when dysfunctional, might result in a behavior that favors the preoccupation with particular thoughts, behaviors, anxieties, and uncontrollable urges that are accompanied by little scope for ongoing behavioral adjustments (e.g., impulse control). We reason that this network may turn out to be equally involved in understudied mental conditions of dysfunctional body processing such as muscle dysmorphia, body dysmorphic disorder (including esthetic surgery), and xelomelia. We finally consider previous notions of a wider phenotype approach to current diagnostic practice (using DSM), such as the possibility of a model with a reduced number of diagnostic categories and primary and secondary factors, and to etiological models of mental health conditions.

On the convergence of EM-like algorithms for image segmentation using Markov random fields.

Inference of Markov random field images segmentation models is usually performed using iterative methods which adapt the well-known expectation-maximization (EM) algorithm for independent mixture models. However, some of these adaptations are ad hoc and may turn out numerically unstable. In this paper, we review three EM-like variants for Markov random field segmentation and compare their convergence properties both at the theoretical and practical levels. We specifically advocate a numerical scheme involving asynchronous voxel updating, for which general convergence results can be established. Our experiments on brain tissue classification in magnetic resonance images provide evidence that this algorithm may achieve significantly faster convergence than its competitors while yielding at least as good segmentation results.