45 research outputs found

    Les Dissections des artères vertébrales intracraniennes (à propos de 11 observations)

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    PARIS5-BU MĂ©d.Cochin (751142101) / SudocPARIS-BIUM (751062103) / SudocCentre Technique Livre Ens. Sup. (774682301) / SudocSudocFranceF

    Identification of reliable sulcal patterns of the human rolandic region

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    A major feature of the human cortex is its huge morphological variability. Although a comprehensive literature about the sulco-gyral pattern of the central region is available from post-mortem data, a reliable and reproducible characterization from in vivo data is still lacking. The aim of this study was to test the reliability of morphological criteria of the central region sulci used in post-mortem data, when applied to in vivo MRI data.Thirty right-handed healthy individuals were included in the study. Automated segmentation and three-dimensional surface-based rendering were obtained from clinical 3D T1-weighted MRI. Two senior radiologists labelled the three sulci composing the central region (precentral [PreCS], central [CS] and postcentral [PostCS]) and analyzed their morphological variations using 47 standard criteria derived from Ono’s atlas based on post-mortem data. For each criterion, inter-rater concordance and comparison with the occurrence frequency provided in Ono’s atlas were estimated. Overall, the sulcal pattern criteria derived from MRI data were highly reproducible between the raters with a high mean inter-rater concordance in the three sulci (CS: =0.92 in left hemisphere / =0.91 in right hemisphere; PreCS: =0.91/ =0.93; PostCS: = 0.84 / 0.79). Only a very limited number of sulcal criteria significantly differed between the in vivo and the post-mortem data (CS: 2 criteria in the left hemisphere / 3 criteria in the right hemisphere; PreCS: 3 in the left and right hemispheres; PostCS: 3 in the left hemisphere and 5 in the right hemisphere). Our study provides a comprehensive description of qualitative sulcal patterns in the central region from in vivo clinical MRI with high agreement with previous post-mortem data. Such identification of reliable sulcal patterns of the central region visible with standard clinical MRI data paves the way for the detection of subtle variations of the central sulcation associated with variations of normal or pathological functioning

    Sulcus-based MR analysis of focal cortical dysplasia located in the central region.

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    Focal cortical dysplasias (FCDs) are mainly located in the frontal region, with a particular tropism for the central sulcus. Up to 30% of lesions are undetected (magnetic resonance [MR]-negative FCD patients) or belatedly diagnosed by visual analysis of MR images. We propose an automated sulcus-based method to analyze abnormal sulcal patterns associated with central FCD, taking into account the normal interindividual sulcal variability.We retrospectively studied 29 right-handed patients with FCD in the central region (including 12 MR negative histologically-confirmed cases) and 29 right-handed controls. The analysis of sulcal abnormalities from T1-weighted MR imaging (MRI) was performed using a graph-based representation of the cortical folds and an automated sulci recognition system, providing a new quantitative criterion to describe sulcal patterns, termed sulcus energy.Group analysis showed that the central sulcus in the hemisphere ipsilateral to the FCD exhibited an abnormal sulcal pattern compared with controls (p = 0.032). FCDs were associated with abnormal patterns of the central sulci compared with controls (p = 0.006), a result that remained significant when MR-negative and MR-positive patients were considered separately, while the effects of sex, age and MR-field were not significant. At the individual level, sulcus energy alone failed to detect the FCD lesion. We found, however, a significant association between maximum z-scores and the site of FCD (p = 0.0046) which remained significant in MR-negative (p = 0.024) but not in MR-positive patients (p = 0.058). The maximum z-score pointed to an FCD sulcus in four MR-negative and five MR-positive patients.We identified abnormal sulcal patterns in patients with FCD of the central region compared with healthy controls. The abnormal sulcal patterns ipsilateral to the FCD and the link between sulcus energy and the FCD location strengthen the interest of sulcal abnormalities in FCD patients

    In vivo imaging of uterine cervix with a Mueller polarimetric colposcope

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    Mueller polarimetric imaging enables the detection and quantification of modifications of the collagen fibers in the uterine cervix due to the development of a precancerous lesion. This information is not accessible through the use of the classic colposcope, a low magnification microscope used in current practice for cervical cancer screening. However, the in vivo application of Mueller polarimetric imaging poses an instrumental challenge: The device should be sufficiently compact, while still being able to perform fast and accurate acquisition of Mueller matrices in real-world conditions. In this study, the first wide field Mueller Polarimetric Colposcope (MPC) for the in vivo analysis of uterine cervix is presented. The MPC has been fabricated by grafting a miniaturized Mueller polarimetric imager on a classic colposcope. This new imaging tool performs the fast acquisition of Mueller polarimetric images, thus eliminating any blurring effects due to patient movements. It can be easily used by a practitioner with little change to their existing practice. Finally, the MPC was tested in vivo on a number of patients in the field.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

    Flowchart of the sulcus-based analysis.

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    <p>A) Processing steps for the controls. First, based on T1-weighted MRI (T1w MRI), cortical sulci were extracted. They were then automatically labeled (one color per label). The sulcus energy maps derived from this recognition process were then generated (blue to red colors, reflecting a sulcus pattern with a good match to the learning database and a bad match, respectively). These maps were averaged to obtain mean and standard deviation (SD) maps. B) Processing steps for a single FCD patient. Cortical sulci extraction, labeling, and generation of sulcus energy map were done as described in A. Finally, a sulcus energy z-score map was computed by dividing the difference between the sulcus energy of the patient and the mean sulcus energy of controls by the standard deviation of controls (blue to red colors, reflecting an increasing z-score).</p
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