Central and Cortical Gray Mater Segmentation of Magnetic Resonance Images of the Fetal Brain

Motivation. The study of human brain development in itsearly stage is today possible thanks to in vivo fetalmagnetic resonance imaging (MRI) techniques. Aquantitative analysis of fetal cortical surfacerepresents a new approach which can be used as a markerof the cerebral maturation (as gyration) and also forstudying central nervous system pathologies [1]. However,this quantitative approach is a major challenge forseveral reasons. First, movement of the fetus inside theamniotic cavity requires very fast MRI sequences tominimize motion artifacts, resulting in a poor spatialresolution and/or lower SNR. Second, due to the ongoingmyelination and cortical maturation, the appearance ofthe developing brain differs very much from thehomogenous tissue types found in adults. Third, due tolow resolution, fetal MR images considerably suffer ofpartial volume (PV) effect, sometimes in large areas.Today extensive efforts are made to deal with thereconstruction of high resolution 3D fetal volumes[2,3,4] to cope with intra-volume motion and low SNR.However, few studies exist related to the automatedsegmentation of MR fetal imaging. [5] and [6] work on thesegmentation of specific areas of the fetal brain such asposterior fossa, brainstem or germinal matrix. Firstattempt for automated brain tissue segmentation has beenpresented in [7] and in our previous work [8]. Bothmethods apply the Expectation-Maximization Markov RandomField (EM-MRF) framework but contrary to [7] we do notneed from any anatomical atlas prior. Data set &Methods. Prenatal MR imaging was performed with a 1-Tsystem (GE Medical Systems, Milwaukee) using single shotfast spin echo (ssFSE) sequences (TR 7000 ms, TE 180 ms,FOV 40 x 40 cm, slice thickness 5.4mm, in plane spatialresolution 1.09mm). Each fetus has 6 axial volumes(around 15 slices per volume), each of them acquired inabout 1 min. Each volume is shifted by 1 mm with respectto the previous one. Gestational age (GA) ranges from 29to 32 weeks. Mother is under sedation. Each volume ismanually segmented to extract fetal brain fromsurrounding maternal tissues. Then, in-homogeneityintensity correction is performed using [9] and linearintensity normalization is performed to have intensityvalues that range from 0 to 255. Note that due tointra-tissue variability of developing brain someintensity variability still remains. For each fetus, ahigh spatial resolution image of isotropic voxel size of1.09 mm is created applying [2] and using B-splines forthe scattered data interpolation [10] (see Fig. 1). Then,basal ganglia (BS) segmentation is performed on thissuper reconstructed volume. Active contour framework witha Level Set (LS) implementation is used. Our LS follows aslightly different formulation from well-known Chan-Vese[11] formulation. In our case, the LS evolves forcing themean of the inside of the curve to be the mean intensityof basal ganglia. Moreover, we add local spatial priorthrough a probabilistic map created by fitting anellipsoid onto the basal ganglia region. Some userinteraction is needed to set the mean intensity of BG(green dots in Fig. 2) and the initial fitting points forthe probabilistic prior map (blue points in Fig. 2). Oncebasal ganglia are removed from the image, brain tissuesegmentation is performed as described in [8]. Results.The case study presented here has 29 weeks of GA. Thehigh resolution reconstructed volume is presented in Fig.1. The steps of BG segmentation are shown in Fig. 2.Overlap in comparison with manual segmentation isquantified by the Dice similarity index (DSI) equal to0.829 (values above 0.7 are considered a very goodagreement). Such BG segmentation has been applied on 3other subjects ranging for 29 to 32 GA and the DSI hasbeen of 0.856, 0.794 and 0.785. Our segmentation of theinner (red and blue contours) and outer cortical surface(green contour) is presented in Fig. 3. Finally, torefine the results we include our WM segmentation in theFreesurfer software [12] and some manual corrections toobtain Fig.4. Discussion. Precise cortical surfaceextraction of fetal brain is needed for quantitativestudies of early human brain development. Our workcombines the well known statistical classificationframework with the active contour segmentation forcentral gray mater extraction. A main advantage of thepresented procedure for fetal brain surface extraction isthat we do not include any spatial prior coming fromanatomical atlases. The results presented here arepreliminary but promising. Our efforts are now in testingsuch approach on a wider range of gestational ages thatwe will include in the final version of this work andstudying as well its generalization to different scannersand different type of MRI sequences. References. [1]Guibaud, Prenatal Diagnosis 29(4) (2009). [2] Rousseau,Acad. Rad. 13(9), 2006, [3] Jiang, IEEE TMI 2007. [4]Warfield IADB, MICCAI 2009. [5] Claude, IEEE Trans. Bio.Eng. 51(4) (2004). [6] Habas, MICCAI (Pt. 1) 2008. [7]Bertelsen, ISMRM 2009 [8] Bach Cuadra, IADB, MICCAI 2009.[9] Styner, IEEE TMI 19(39 (2000). [10] Lee, IEEE Trans.Visual. And Comp. Graph. 3(3), 1997, [11] Chan, IEEETrans. Img. Proc, 10(2), 2001 [12] Freesurfer,http://surfer.nmr.mgh.harvard.edu.

Als Marie Bonaparte sich taub stellte ...

Between 1927 and 1931 Marie Bonaparte had herself operated upon her clitoris three times. She did so against Freud's advice with whom she was in analysis. Among psychoanalysts these operations are still often regarded as "errors" or aberrations. But for Marie Bonaparte, who was in various ways familiar with physics and a somatic approach, surgery was the first choice, psychoanalysis only a possible alternative. She was not impressed by the skepticism of her colleagues, and adhered even more emphatically to her own strategy

GDAP1-related autosomal dominant Charcot-Marie-Tooth disease: phenotypical and MRI features

El present estudi es basa en la descripció de quatre famílies portadores d’una mateixa mutació puntual (p.R120W) en el gen GDAP1 que segreguen d’una manera autosòmica dominant. Les trobades més rellevants foren:  Els individus afectats varen tindre un començament més tardà i un fenotipus més lleu que les mutacions recessives del gen GDAP-1, però amb una gran variabilitat clínica.  La Resonància Magnètica Muscular va demostrar una afectació selectiva de la musculatura intrínseca del peu i la part distal del panxell. El compartiment posterior superficial de la musculatura del panxell estava més afectat que el compartiment anterolateral.

Première apocalypse apocryphe de Jean

(Résumé de l'ouvrage) Les textes recueillis dans ces deux volumes sont des apocryphes, ce qui signifie qu'en dépit d'un contenu comparable à celui des Écritures ils n'appartiennent pas au canon. En effet, soit ils s'écartent de la doctrine officielle de l'Église en véhiculant des idées hétérodoxes, soit ils font trop appel au merveilleux, aspect dont l'Église s'est toujours méfiée. Mais rappelons que le canon des Écritures n'a pas été fixé tout de suite, son histoire court jusqu'à la quatrième session du Concile de Trente (1546). Ajoutons aussi qu'il y a toujours désaccord en la matière entre l'Église catholique et les Églises protestantes pour certains livres. Les textes réunis dans le premier tome relèvent de l'Antiquité chrétienne et recoupent différents genres bibliques : évangiles (auquel il convient d'adjoindre des écrits relatant la vie et la dormition de Marie, mère de Jésus), épîtres, Actes des apôtres, apocalypses (sur les derniers temps et l'au-delà). Ces pièces sont précieuses. Elles permettent une connaissance plus approfondie des premiers temps de l'Église et la compréhension de traditions - dans le domaine de la piété, de la liturgie ou de l'art - dont nous n'avons pas trace dans les textes canoniques. Les textes réunis dans le second tome sont, dans leur majorité, plus tardifs. Ce volume accorde, d'autre part, une place plus grande que le premier à des livres qui circulèrent dans des aires religieuses et linguistiques autres que le monde byzantin et l'Occident latin ; les traditions copte, arabe, éthiopienne, arménienne y sont bien représentées. Pour la plupart, ces écrits n'avaient encore jamais été publiés en langue française. Les écrits chrétiens que l'on dit « apocryphes » n'ont cessé d'être diffusés, récrits, adaptés. Ils furent le terreau de l'imaginaire chrétien, et une source d'inspiration pour les sculpteurs, les peintres, les écrivains, les musiciens et les cinéastes : le Bunuel de La Voie lactée se souvient des Actes de Jean. C'est que, face au discours régnant, institutionnel, ces textes ouvrent un espace à l'imagination. Ils se développent en quelque sorte dans les interstices des livres canoniques. Ils comblent des vides, inscrivent une parole dans les silences, donnent une voix aux personnages muets, un nom et un visage à ceux qui n'étaient que des ombres. Comme toute littérature, ils rusent avec le discours clos.

Estimating attributable mortality due to nosocomial infections acquired in intensive care units.

BACKGROUND: The strength of the association between intensive care unit (ICU)-acquired nosocomial infections (NIs) and mortality might differ according to the methodological approach taken. OBJECTIVE: To assess the association between ICU-acquired NIs and mortality using the concept of population-attributable fraction (PAF) for patient deaths caused by ICU-acquired NIs in a large cohort of critically ill patients. SETTING: Eleven ICUs of a French university hospital. DESIGN: We analyzed surveillance data on ICU-acquired NIs collected prospectively during the period from 1995 through 2003. The primary outcome was mortality from ICU-acquired NI stratified by site of infection. A matched-pair, case-control study was performed. Each patient who died before ICU discharge was defined as a case patient, and each patient who survived to ICU discharge was defined as a control patient. The PAF was calculated after adjustment for confounders by use of conditional logistic regression analysis. RESULTS: Among 8,068 ICU patients, a total of 1,725 deceased patients were successfully matched with 1,725 control patients. The adjusted PAF due to ICU-acquired NI for patients who died before ICU discharge was 14.6% (95% confidence interval [CI], 14.4%-14.8%). Stratified by the type of infection, the PAF was 6.1% (95% CI, 5.7%-6.5%) for pulmonary infection, 3.2% (95% CI, 2.8%-3.5%) for central venous catheter infection, 1.7% (95% CI, 0.9%-2.5%) for bloodstream infection, and 0.0% (95% CI, -0.4% to 0.4%) for urinary tract infection. CONCLUSIONS: ICU-acquired NI had an important effect on mortality. However, the statistical association between ICU-acquired NI and mortality tended to be less pronounced in findings based on the PAF than in study findings based on estimates of relative risk. Therefore, the choice of methods does matter when the burden of NI needs to be assessed.

Early-onset ventilator-associated pneumonia incidence in intensive care units: a surveillance-based study.

ABSTRACT: BACKGROUND: The incidence of ventilator-associated pneumonia (VAP) within the first 48 hours of intensive care unit (ICU) stay has been poorly investigated. The objective was to estimate early-onset VAP occurrence in ICUs within 48 hours after admission. METHODS: We analyzed data from prospective surveillance between 01/01/2001 and 31/12/2009 in 11 ICUs of Lyon hospitals (France). The inclusion criteria were: first ICU admission, not hospitalized before admission, invasive mechanical ventilation during first ICU day, free of antibiotics at admission, and ICU stay >=48 hours. VAP was defined according to a national protocol. Its incidence was the number of events per 1,000 invasive mechanical ventilation-days. The Poisson regression model was fitted from day 2 (D2) to D8 to incident VAP to estimate the expected VAP incidence from D0 to D1 of ICU stay. RESULTS: Totally, 367 (10.8%) of 3,387 patients in 45,760 patient-days developed VAP within the first 9 days. The predicted cumulative VAP incidence at D0 and D1 was 5.3 (2.6-9.8) and 8.3 (6.1-11.1), respectively. The predicted cumulative VAP incidence was 23.0 (20.8-25.3) at D8. The proportion of missed VAP within 48 hours from admission was 11% (9%-17%). CONCLUSIONS: Our study indicates underestimation of early-onset VAP incidence in ICUs, if only VAP occurring [greater than or equal to]48 hours is considered to be hospital-acquired. Clinicians should be encouraged to develop a strategy for early detection after ICU admission.

Réclamations pour le Sr Charles-Marie-Canalès-Oglou,... seul et unique héritier de feu Sr Jean-Marie-Alix de Boullon-Morange,... demandeur, contre dame Marie-Elisabeth-Emilie Aubourg, veuve du sieur Léonard Robin, décédé commissaire du gouvernement près le Tribunal civil... de la Seine, et membre du Tribunat, et encore contre le sieur Louis-Léonard Robin, se prétendant fils et unique héritier dudit sieur Léonard Robin... défendeurs, adressées à S. M. Napoléon-le-Grand,... / [Signé : Canalès-Oglou, 12 août 1806. - Consultation pour le sieur Canalès-Oglou contre les héritiers Robin. Signé : Adam, ancien avocat ; Bonhomme, avocat, 16 août 1806.]

[Factum. Boullon-Morange, Mehemet-Aly, dit Jean-Marie-Alix deSuccession). 1806?]