119 results on '"Meder, Jean-François"'
Search Results
102. Diffusion tensor imaging of partial intractable epilepsy.
- Author
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de la Roque, Anne Dumas, Oppenheim, Catherine, Chassoux, Francine, Rodrigo, Sebastian, Beuvon, Frédéric, Daumas-Duport, Catherine, Devaux, Bertrand, and Meder, Jean-François
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EPILEPSY ,BRAIN ,MEDICAL imaging systems ,DIAGNOSTIC imaging ,RADIOLOGY ,MEDICAL research - Abstract
Our aim was to assess the value of diffusion tensor imaging (DTI) in patients with partial intractable epilepsy. We used DTI (25 non-collinear directions) in 15 patients with a cortical lesion on conventional MRI. Fractional anisotropy (FA) was measured in the internal capsule, and in the normal-appearing white matter (WM),adjacent tothe lesion, andaway fromthe lesion, at a set distance of 2-3 cm. In each patient, increased or decreased FA measurements were those that varied from mirror values using an arbitrary 10% threshold. Over the whole population, ipsi- and contralateral FA measurements were also compared using a Wilcoxon test (p<0.05). Over the whole population, FA was significantly reduced in the WMadjacent toandaway fromthe lesion, whilst being normal in the internal capsule. FA was reduced by more than 10% in the WMadjacent toanddistant fromthe lesion in 13 and 12 patients respectively. For nine of the ten patients for whom the surgical resection encompassed the limits of the lesion on conventional MRI, histological data showed WM alterations (gliosis, axonal loss, abnormal cells). DTI often reveals WM abnormalities that are undetected on conventional MRI in patients with partial intractable epilepsy. [ABSTRACT FROM AUTHOR]
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- 2005
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103. IRM à trois semaines d’une cure chirurgicale de hernie discale : aspect trompeur de récidive herniaire avec prise de contraste radiculaire
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Randoux, Bruno, Page, Philippe, Méary, Éric, Frédy, Daniel, and Méder, Jean-François
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- 2001
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104. Is White Matter More Prone to Diffusion Lesion Reversal After Thrombolysis?
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Tisserand, Marie, Malherbe, Caroline, Turc, Guillaume, Legrand, Laurence, Edjlali, Myriam, Labeyrie, Marc-Antoine, Seners, Pierre, Mas, Jean-Louis, Meder, Jean-François, Baron, Jean-Claude, and Oppenheim, Catherine
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- 2014
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105. MEAH - Mission nationale d’expertise et d’audit hospitalier : évaluation de l’organisation des services de radiologie
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Pruvo, Jean-Pierre, Méder, Jean-François, and Valette, Pierre-Jean
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- 2004
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106. Giant intradiploic epidermoid cysts of the skull
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Constans, Jean Paul, primary, Meder, Jean François, additional, De Divitiis, Enrico, additional, Donzelli, Renato, additional, and Maiuri, Francesco, additional
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- 1985
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107. Generative adversarial networks (GAN)-based data augmentation of rare liver cancers: The SFR 2021 Artificial Intelligence Data Challenge.
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Mulé S, Lawrance L, Belkouchi Y, Vilgrain V, Lewin M, Trillaud H, Hoeffel C, Laurent V, Ammari S, Morand E, Faucoz O, Tenenhaus A, Cotten A, Meder JF, Talbot H, Luciani A, and Lassau N
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- Humans, Artificial Intelligence, Image Processing, Computer-Assisted methods, Algorithms, Liver Neoplasms diagnostic imaging, Carcinoma, Hepatocellular diagnostic imaging
- Abstract
Purpose: The 2021 edition of the Artificial Intelligence Data Challenge was organized by the French Society of Radiology together with the Centre National d'Études Spatiales and CentraleSupélec with the aim to implement generative adversarial networks (GANs) techniques to provide 1000 magnetic resonance imaging (MRI) cases of macrotrabecular-massive (MTM) hepatocellular carcinoma (HCC), a rare and aggressive subtype of HCC, generated from a limited number of real cases from multiple French centers., Materials and Methods: A dedicated platform was used by the seven inclusion centers to securely upload their anonymized MRI examinations including all three cross-sectional images (one late arterial and one portal-venous phase T1-weighted images and one fat-saturated T2-weighted image) in compliance with general data protection regulation. The quality of the database was checked by experts and manual delineation of the lesions was performed by the expert radiologists involved in each center. Multidisciplinary teams competed between October 11
th , 2021 and February 13th , 2022., Results: A total of 91 MTM-HCC datasets of three images each were collected from seven French academic centers. Six teams with a total of 28 individuals participated in this challenge. Each participating team was asked to generate one thousand 3-image cases. The qualitative evaluation was performed by three radiologists using the Likert scale on ten randomly selected cases generated by each participant. A quantitative evaluation was also performed using two metrics, the Frechet inception distance and a leave-one-out accuracy of a 1-Nearest Neighbor algorithm., Conclusion: This data challenge demonstrates the ability of GANs techniques to generate a large number of images from a small sample of imaging examinations of a rare malignant tumor., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interest., (Copyright © 2022 Société française de radiologie. Published by Elsevier Masson SAS. All rights reserved.)- Published
- 2023
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108. French Imaging Database Against Coronavirus (FIDAC): A large COVID-19 multi-center chest CT database.
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Boussel L, Bartoli JM, Adnane S, Meder JF, Malléa P, Clech J, Zins M, and Bérégi JP
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- COVID-19 Testing, Humans, Pandemics, Retrospective Studies, SARS-CoV-2, Tomography, X-Ray Computed methods, COVID-19
- Abstract
Purpose: During the first wave of the COVID-19 pandemic, the French Society of Radiology and the French College of Radiology, in partnership with NEHS Digital, have set up a system to collect chest computed tomography (CT) examinations with clinical, virological and radiological metadata, from patients clinically suspected of COVID-19 pneumonia. This allowed the constitution of an anonymized multicenter database, named FIDAC (French Imaging Database Against Coronavirus). The aim of this report was to describe the content of this public database., Materials and Methods: Twenty-two French radiology centers participated to the data collection. The data collected were chest CT examinations in DICOM format associated with the following metadata: patient age and sex, originating facility identifier, originating facility region, time from symptom onset to CT examination, indication for CT examination, reverse transcription-polymerase chain reaction (RT-PCR) results and normalized CT report performed by a senior radiologist. All the data were anonymized and sent through a NEHS Digital system to a centralized data center., Results: A total of 5944 patients were included from the 22 centers aggregated into 8 regions with a mean number of patients of 743 ± 603.3 [SD] per region (range: 102-1577 patients). Reasons for CT examination and normalized CT reports were provided for all patients. RT-PCR results were provided in 5574 patients (93.77%) with a positive result of RT-PCR in 44.6% of patients., Conclusion: The FIDAC project allowed the creation of a large database of chest CT images and metadata available, under conditions, in open access through the CERF-SFR website., (Copyright © 2022 Société française de radiologie. Published by Elsevier Masson SAS. All rights reserved.)
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- 2022
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109. Validation of a post-mortem computed tomography method for age estimation based on the 4th rib in a French population.
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Richard ME, Delabarde T, Hmeydia G, Provost C, de Jong L, Hamza L, Meder JF, Oppenheim C, Ludes B, and Benzakoun J
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- Female, Humans, Reproducibility of Results, Tomography, Age Determination by Skeleton methods, Ribs diagnostic imaging
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Age estimation is a key factor for identification procedure in forensic context. Based on anthropological findings, degenerative changes of the sternal extremity of the 4th rib are currently used for age estimation. These have been adapted to post-mortem computed tomography (PMCT). The aim of this study was to validate a post-mortem computed tomography method based on a revision of the Iscan's method on a French sample. A total of 250 PMCT (aged from 18-98 years (IQR 36-68 years, median 51 years); 68 (27%) females) from the Medicolegal Institute of Paris (MLIP) were analyzed by two radiologists. The sternal extremity of 4th right rib was scored using method adapted from Iscan et al. Weighted κ was used to evaluate intra- and inter-observer reliability and Spearman correlation was performed to evaluate relationship between age and score. Confidence intervals for individual prediction of age based on 4th rib score and sex were computed with bootstrapping. The intra-observer reliability and inter-observer reliability were almost perfect (weighted κ = 0.85 [95%CI: 0.78-0.93] and 0.82 [95%CI 0.70-0.96] respectively). We confirmed a high correlation between the 4th rib score and subject age (rho = 0.72, p < 0.001), although the confidence intervals for individual age prediction were large, spanning over several decades. This study confirms the high reliability of Iscan method applied to PMCT for age estimation, although future multimodal age prediction techniques may help reducing the span of confidence intervals for individual age estimation.Trial registration: INDS 0,509,211,020, October 2020, retrospectively registered., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
- Published
- 2022
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110. Three artificial intelligence data challenges based on CT and ultrasound.
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Lassau N, Bousaid I, Chouzenoux E, Verdon A, Balleyguier C, Bidault F, Mousseaux E, Harguem-Zayani S, Gaillandre L, Bensalah Z, Doutriaux-Dumoulin I, Monroc M, Haquin A, Ceugnart L, Bachelle F, Charlot M, Thomassin-Naggara I, Fourquet T, Dapvril H, Orabona J, Chamming's F, El Haik M, Zhang-Yin J, Guillot MS, Ohana M, Caramella T, Diascorn Y, Airaud JY, Cuingnet P, Gencer U, Lawrance L, Luciani A, Cotten A, and Meder JF
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- Humans, Radiologists, Ultrasonography, Artificial Intelligence, Tomography, X-Ray Computed
- Abstract
Purpose: The 2020 edition of these Data Challenges was organized by the French Society of Radiology (SFR), from September 28 to September 30, 2020. The goals were to propose innovative artificial intelligence solutions for the current relevant problems in radiology and to build a large database of multimodal medical images of ultrasound and computed tomography (CT) on these subjects from several French radiology centers., Materials and Methods: This year the attempt was to create data challenge objectives in line with the clinical routine of radiologists, with less preprocessing of data and annotation, leaving a large part of the preprocessing task to the participating teams. The objectives were proposed by the different organizations depending on their core areas of expertise. A dedicated platform was used to upload the medical image data, to automatically anonymize the uploaded data., Results: Three challenges were proposed including classification of benign or malignant breast nodules on ultrasound examinations, detection and contouring of pathological neck lymph nodes from cervical CT examinations and classification of calcium score on coronary calcifications from thoracic CT examinations. A total of 2076 medical examinations were included in the database for the three challenges, in three months, by 18 different centers, of which 12% were excluded. The 39 participants were divided into six multidisciplinary teams among which the coronary calcification score challenge was solved with a concordance index > 95%, and the other two with scores of 67% (breast nodule classification) and 63% (neck lymph node calcifications)., (Published by Elsevier Masson SAS.)
- Published
- 2021
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111. Proposals for the use of artificial intelligence in emergency radiology.
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Jacques T, Fournier L, Zins M, Adamsbaum C, Chaumoitre K, Feydy A, Millet I, Montaudon M, Beregi JP, Bartoli JM, Cart P, Masson JP, Meder JF, Boyer L, and Cotten A
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- Humans, Radiography, Artificial Intelligence, Radiology
- Published
- 2021
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112. Subarachnoid hemorrhage
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Boulouis G, Trystram D, Nataf F, Rodriguez C, Devaux B, Oppenheim C, Meder JF, and Naggara O
- Abstract
Competing Interests: G. Boulouis, D. Trystram, F. Nataf, C. Rodriguez, B. Devaux, C. Oppenheim, J.-F. Meder et O. Naggara déclarent n’avoir aucun lien d’intérêts.
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- 2015
113. Subarachnoid hemorrhage Imaging
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Boulouis G, Trystram D, Nataf F, Rodriguez C, Devaux B, Oppenheim C, Meder JF, and Naggara O
- Abstract
Competing Interests: G. Boulouis, D. Trystram, F. Nataf, C. Rodriguez, B. Devaux, C. Oppenheim, J.-F. Meder et O. Naggara déclarent n’avoir aucun lien d’intérêts.
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- 2015
114. Dysembryoplastic neuroepithelial tumors: an MRI-based scheme for epilepsy surgery.
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Chassoux F, Rodrigo S, Mellerio C, Landré E, Miquel C, Turak B, Laschet J, Meder JF, Roux FX, Daumas-Duport C, and Devaux B
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- Adolescent, Adult, Age of Onset, Brain pathology, Brain Neoplasms complications, Brain Neoplasms pathology, Carcinoma complications, Carcinoma pathology, Child, Drug Resistance, Electroencephalography, Epilepsy etiology, Epilepsy pathology, Female, Humans, Male, Middle Aged, Seizures surgery, Treatment Outcome, Young Adult, Brain Neoplasms surgery, Carcinoma surgery, Epilepsy surgery, Magnetic Resonance Imaging methods, Neurosurgical Procedures methods, Surgery, Computer-Assisted methods
- Abstract
Objective: To determine optimal resections in the 3 dysembryoplastic neuroepithelial tumor (DNT) histologic subtypes (simple, complex, and nonspecific) based on MRI features., Methods: In 78 consecutive epilepsy patients operated for DNT, MRI features were classified as follows: type 1 (cystic/polycystic-like, well-delineated, strongly hypointense T1), type 2 (nodular-like, heterogeneous), or type 3 (dysplastic-like, iso/hyposignal T1, poor delineation, gray-white matter blurring). Correlations between histology, neurophysiologic findings, and surgical outcome were established for each MRI subtype., Results: Type 1 MRI (25 cases, in temporal and extratemporal areas) always corresponded to simple or complex DNTs. Type 2 MRI (25 cases, predominantly in neocortical areas) and type 3 MRI (28 cases, mainly in the mesial temporal lobe) corresponded to nonspecific forms. The epileptogenic zone (EZ) differed significantly according to the MRI subtype (p = 0.0029). It colocalized with the tumor in type 1 MRI, included perilesional cortex in type 2 MRI, and involved extensive areas in type 3 MRI. Cortical dysplasia was predominantly found in type 3 MRI (p < 0.0001). The main prognostic factors for seizure-free outcome (83%) were complete tumor (p < 0.0001) and EZ (p = 0.0115) removal. Other factors favorably influencing the outcome were a short epilepsy duration (p = 0.013) and absence of cortical-subcortical damage at the resection site (p = 0.053). Age at surgery was not related to outcome; however, cortical-subcortical damage was correlated with old age (p = 0.021). Treatment discontinuation was correlated with young age at surgery (p = 0.004) and short epilepsy duration (p = 0.001)., Conclusion: We propose that resection might be restricted to the tumor in type 1 MRI and be more extensive in other MRI subtypes, especially in type 3 MRI. Early surgery and clean surgical margins are crucial for curing epilepsy.
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- 2012
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115. [Brain imaging patterns after stroke].
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Oppenheim C, Lamy C, Mas JL, and Meder JF
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- Acute Disease, Aorta, Thoracic, Aortic Diseases diagnosis, Atherosclerosis complications, Atherosclerosis diagnosis, Cerebral Hemorrhage diagnosis, Cerebral Infarction diagnostic imaging, Cerebral Infarction etiology, Heart Septal Defects, Atrial complications, Heart Septal Defects, Atrial diagnosis, Humans, Intracranial Thrombosis complications, Intracranial Thrombosis diagnosis, Magnetic Resonance Angiography, Magnetic Resonance Imaging, Stroke diagnostic imaging, Stroke etiology, Time Factors, Tomography, X-Ray Computed, Vertebral Artery Dissection complications, Vertebral Artery Dissection diagnosis, Cerebral Infarction diagnosis, Stroke diagnosis
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The advent of new imaging techniques, such as diffusion-weighted sequences, has a great impact on the diagnostic imaging in stroke. The aim of the present paper is to review the brain imaging patterns after stroke, highlight the usefulness of imaging technique for the diagnosis and etiological work-up after stroke. Three causes of ischemic stroke (cerebral venous thrombosis, aortic arch atheroma, patent foramen ovale) are detailed.
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- 2006
116. [Cerebral venous and sinus thrombosis].
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Zuber M and Meder JF
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- Humans, Prognosis, Risk Factors, Intracranial Thrombosis diagnosis, Intracranial Thrombosis drug therapy, Intracranial Thrombosis etiology, Sinus Thrombosis, Intracranial diagnosis, Sinus Thrombosis, Intracranial drug therapy, Sinus Thrombosis, Intracranial etiology, Venous Thrombosis diagnosis, Venous Thrombosis drug therapy, Venous Thrombosis etiology
- Abstract
Cerebral venous thrombosis is a rare and life threatening condition that should be considered in all individual with unusual and intractable headache. Young adults and children are typically affected and the superior sagittal sinus is most often concerned by thrombosis. MRI is the most sensitive examination technique and is now required for early diagnosis, leading to an improved prognosis. One or several prothrombotic risk factors are identified in most patients but about 20% of cerebral venous thrombosis have no cause identified. Anticoagulation is started as soon as the diagnosis is considered, even in the presence of hemorrhagic infarcts, and rapidly improves the condition in most patients. In situ thrombolysis is exceptionally delivered.
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- 2006
117. Three-dimensional dynamic MR digital subtraction angiography using sensitivity encoding for the evaluation of intracranial arteriovenous malformations: a preliminary study.
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Gauvrit JY, Leclerc X, Oppenheim C, Munier T, Trystram D, Rachdi H, Nataf F, Pruvo JP, and Meder JF
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- Adult, Female, Humans, Male, Middle Aged, Angiography, Digital Subtraction, Imaging, Three-Dimensional, Intracranial Arteriovenous Malformations diagnosis, Magnetic Resonance Angiography methods
- Abstract
Background and Purpose: Our aim was to develop 3D dynamic MR digital subtraction angiography with high temporal resolution without sacrificing spatial resolution by using sensitivity encoding for the evaluation of cerebral arteriovenous malformations., Methods: Nineteen patients with 19 angiographically proven arteriovenous malformations (16 supratentorial and 3 infratentorial) were assessed by conventional catheter angiography and 3D dynamic MR digital subtraction angiography. A 3D contrast-enhanced gradient-echo sequence with sensitivity encoding based on a parallel imaging technique was performed and acquired 20 dynamic images, repeated 18 times every 1.7 seconds. Three-dimensional dynamic MR digital subtraction angiograms were analyzed independently by two radiologists in a blinded fashion with regard to arteriovenous malformation nidus and venous drainage. Conventional catheter angiography was used as reference., Results: All MR imaging examinations were assessable. Interobserver agreement was excellent for the detection of nidus and for the evaluation of nidus size (kappa = 1 and 0.875, respectively) but moderate for the visualization of the venous drainage (kappa = 0.56). All nidi detected on conventional catheter angiography were clearly depicted on 3D dynamic MR digital subtraction angiography. The evaluation of the size of the nidus by both techniques was similar. On 3D dynamic MR angiograms, veins were correctly analyzed in 17 of 19 arteriovenous malformations., Conclusion: Our preliminary study demonstrates that 3D dynamic MR digital subtraction angiography using sensitivity encoding with a high spatial resolution is appropriate for the assessment of arteriovenous malformations.
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- 2005
118. Spontaneous intracerebral hematoma on diffusion-weighted images: influence of T2-shine-through and T2-blackout effects.
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Silvera S, Oppenheim C, Touzé E, Ducreux D, Page P, Domigo V, Mas JL, Roux FX, Frédy D, and Meder JF
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- Adult, Aged, Aged, 80 and over, Female, Humans, Male, Middle Aged, Retrospective Studies, Diffusion Magnetic Resonance Imaging methods, Hematoma pathology, Intracranial Hemorrhages pathology
- Abstract
Background and Purpose: On diffusion-weighted (DW) images, primary hematomas are initially mainly hyperintense, and then hypointense during the first few days after stroke onset. As in other brain disorders, variations in the T2 relaxation time of the hematoma influence the DW imaging signal intensity. Our aim was to evaluate the contribution of the T2 signal intensity and apparent diffusion coefficient (ADC) changes to signal intensity displayed by DW imaging through the course of hematoma., Methods: The MR images of 33 patients with primary intracranial hemorrhage were retrospectively reviewed. Variations in T2-weighted echo planar images, DW imaging signal intensity, and apparent diffusion coefficient (ADC) ratios (core of hematoma/contralateral hemisphere) were analyzed according to the putative stages of hematoma, as seen on T1- and T2-weighted images., Results: On both T2-weighted echo planar and DW images, the core of the hematomas was hyperintense at the hyperacute (oxyhemoglobin, n = 11) and late subacute stages (extracellular methemoglobin, n = 4), while being hypointense at the acute (deoxyhemoglobin, n = 11) and early subacute stages (extracellular methemoglobin, n = 7). There was a positive correlation between the signal intensity ratio on T2-weighted echo planar and DW images (r = 0.93, P < .05). ADC ratios were significantly decreased in the whole population and in each of the first three stages of hematoma, without any correlation between DW imaging findings and ADC changes (r = 0.09, P = .6)., Conclusion: Our results confirm that the core of hematomas is hyperintense on DW images with decreased ADC values at the earliest time point, and may thus mimic arterial stroke on DW images. T2 shine-through and T2 blackout effects contribute to the DW imaging findings of hyperintense and hypointense hematomas, respectively, while ADC values are moderately but consistently decreased during the first three stages of hematoma.
- Published
- 2005
119. [Carotid artery angioplasty: where are we in 2004?].
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Beyssen B, Long A, and Meder JF
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- Humans, Angioplasty methods, Carotid Stenosis surgery, Stents
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Carotid artery stenting (CAS) is currently being investigated as an alternative treatment to carotid endarterectomy (CEA). Cerebral embolism is the most serious risk of CAS. Carotid artery stenting is still not reimbursed and unauthorised not authorised in routine in France (excepted in trials with ethical committee approval). CAS is now feasible, with a high technical success, which may improves with learning curve and with a better patient selection of the patients. A number of higher risk situations for CEA represents ideal indications for CAS, such as restenosis after CEA, stenosis due to prior neck radiation and radical neck surgery, and lesions in the distal internal carotid artery or involving high, retromandibular bifurcation.
- Published
- 2004
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