285 results on '"Meder JF"'
Search Results
102. [Diffusion-weighted MR imaging of the brain].
- Author
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Naggara O, Létourneau-Guillon L, Mellerio C, Belair M, Pruvo JP, Leclerc X, Meder JF, and Oppenheim C
- Subjects
- Brain Abscess diagnosis, Brain Ischemia diagnosis, Brain Neoplasms diagnosis, Diagnosis, Differential, Humans, Image Enhancement methods, Prognosis, Brain Diseases diagnosis, Diffusion Magnetic Resonance Imaging methods
- Abstract
Imaging of water diffusion or diffusion-weighted MR imaging provides physiological information about brain diseases that cannot be obtained from conventional sequences. This technique is very sensitive for the detection of cerebral ischemia from arterial origin and can distinguish cerebral ischemia from other non-vascular brain pathologies in patients presenting with abrupt onset of focal neurological deficit. Diffusion-weighted imaging is used for the evaluation of non-vascular diseases as well. Combined with conventional sequences, it is helpful to differentiate brain abscesses from necrotic tumors. Quantitative diffusion-weighted imaging provides additional information in the characterization of tumors or inflammatory, degenerative and metabolic lesions. Finally, diffusion-weighted imaging data also has prognostic value.
- Published
- 2010
- Full Text
- View/download PDF
103. The protective status of subtotal obliteration of arteriovenous malformations after radiosurgery: significance and risk of hemorrhage.
- Author
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Abu-Salma Z, Nataf F, Ghossoub M, Schlienger M, Meder JF, Houdart E, and Roux FX
- Subjects
- Adolescent, Adult, Aged, Cerebral Angiography standards, Cerebral Arteries abnormalities, Cerebral Arteries physiopathology, Cerebral Arteries surgery, Cerebral Hemorrhage physiopathology, Cerebral Hemorrhage prevention & control, Cerebral Veins abnormalities, Cerebral Veins physiopathology, Cerebral Veins surgery, Child, Comorbidity, Female, Humans, Intracranial Arteriovenous Malformations physiopathology, Male, Middle Aged, Postoperative Hemorrhage physiopathology, Postoperative Hemorrhage prevention & control, Radiation Dosage, Radiotherapy Planning, Computer-Assisted, Risk Assessment, Risk Factors, Time Factors, Treatment Outcome, Young Adult, Cerebral Hemorrhage epidemiology, Intracranial Arteriovenous Malformations epidemiology, Intracranial Arteriovenous Malformations surgery, Postoperative Hemorrhage epidemiology, Radiosurgery statistics & numerical data
- Abstract
Objective: Arteriovenous malformations (AVMs) treated by radiosurgery with complete obliteration of the nidus but a persisting early draining vein on follow-up angiography can be termed subtotally obliterated. However, these are persistent circulating AVMs. The significance of these lesions, their hemorrhage rate, and their management are analyzed., Methods: In a series of 862 consecutive patients with AVMs treated by radiosurgery, 121 patients (14%) achieved subtotal obliteration (STO). The angiographic evolution and rate of obliteration were studied. The pretreatment angiographic features, dosimetric parameters, and postradiosurgery hemorrhage rate were compared with those in the rest of the treated population. Finally, the options for follow-up and treatment were analyzed., Results: Of 121 subtotally obliterated AVMs, the bleeding rate was 0%; 53% of patients achieved complete obliteration. This occurred in 71% of those who had STO at 1 year. In the cases in which STO was detected at 2, 3, and 4 years, total obliteration eventually occurred in 43%, 28.5%, and 0%, respectively. Comparative analysis with AVMs in which a part of the nidus persisted showed a significant difference in the bleeding rate. Except for volume, no significant statistical difference in angiographic and dosimetric parameters was found between the STO group and the rest of the studied population with residual nidus. Six cases received further treatment, resulting in 2 cures and 2 treatment-related complications., Conclusion: Subtotally obliterated AVMs are different from other partially obliterated AVMs, with a 0% bleeding rate. Their complete obliteration is a function of delay of appearance on follow-up angiography. Invasive follow-up and further treatment of these AVMs do not seem warranted.
- Published
- 2009
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104. Cerebral vasculopathy is associated with severe vascular manifestations in systemic sclerosis.
- Author
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Terrier B, Charbonneau F, Touzé E, Berezne A, Pagnoux C, Silvera S, Meder JF, Guillevin L, Oppenheim C, and Mouthon L
- Subjects
- Adolescent, Adult, Aged, Cerebrovascular Disorders diagnostic imaging, Cerebrovascular Disorders pathology, Female, Humans, Hypertension, Pulmonary epidemiology, Kidney Diseases epidemiology, Magnetic Resonance Imaging, Male, Middle Aged, Multivariate Analysis, Retrospective Studies, Risk Factors, Tomography, X-Ray Computed, Young Adult, Brain blood supply, Brain pathology, Cerebrovascular Disorders etiology, Scleroderma, Systemic complications
- Abstract
Objective: To investigate brain involvement in patients with systemic sclerosis (SSc)., Methods: Sixty-three patients with SSc fulfilling the American College of Rheumatology and/or Leroy and Medsger criteria were retrospectively studied, including 30 (47.6%) with limited cutaneous and 27 (42.9%) with diffuse cutaneous SSc. Forty-one patients underwent computed tomography (CT) scan and magnetic resonance imaging (MRI) of the brain, 11 patients only CT scan, and the remaining 11 patients only MRI. Cerebral vasculopathy on MRI and CT scan was defined as absent or mild (score < 1), moderate (1
or= 2) on a 4-point scale (0 to 3)., Results: Cerebral vasculopathy was identified on CT scan in 22 patients (moderate in 12 and severe in 10) and on MRI in 38 patients (moderate in 28 and severe in 10). Patients with severe cerebral vasculopathy seen on MRI were more likely to have pulmonary arterial hypertension (PAH; p = 0.003) and showed a tendency to have scleroderma renal crisis (SRC; p = 0.25, test for trend p = 0.097). A similar association was found between severe cerebral vasculopathy seen on CT scan and PAH (p = 0.026) or SRC (p = 0.04). After adjusting for age and hypertension, severe cerebral vasculopathy was still associated with increased risk of severe vascular manifestations [odds ratio (OR) 32, 95% confidence interval (CI) 3.45-297, p = 0.002 for CT scan; OR 26, 95% CI 1.71-394, p = 0.019 for MRI]., Conclusion: Severe cerebral vasculopathy is associated with severe vascular manifestations in SSc patients. SSc patients with severe vascular complications should undergo neuroradiological imaging assessment of brain involvement. - Published
- 2009
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105. [Imaging in a University Medical Center: from concern to hope].
- Author
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Meder JF, Krausé D, and Pruvo JP
- Subjects
- Biomedical Research trends, Forecasting, France, Humans, Technology, Radiologic trends, Academic Medical Centers trends, Diagnostic Imaging trends, Hospitals, University trends, Radiology Department, Hospital trends
- Published
- 2009
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106. Optochiasmal apoplexy due to a cavernoma.
- Author
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Naggara O, Meary E, Marsico R, Oppenheim C, Meder JF, and Nataf F
- Subjects
- Adult, Diagnosis, Differential, Hemangioma, Cavernous pathology, Humans, Magnetic Resonance Imaging, Male, Optic Nerve Neoplasms pathology, Stroke pathology, Vision Disorders pathology, Hemangioma, Cavernous complications, Hemangioma, Cavernous diagnosis, Optic Chiasm pathology, Optic Nerve Neoplasms complications, Optic Nerve Neoplasms diagnosis, Stroke etiology, Vision Disorders etiology
- Published
- 2009
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107. Seizures as the initial symptom of a diffuse dura mater and choroids plexus haematopoiesis revealing myelofibrosis.
- Author
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Naggara O, Meary E, Marsico R, Oppenheim C, and Meder JF
- Subjects
- Contrast Media, Female, Humans, Middle Aged, Primary Myelofibrosis drug therapy, Primary Myelofibrosis pathology, Seizures diagnosis, Choroid Plexus pathology, Dura Mater pathology, Hematopoiesis, Magnetic Resonance Imaging methods, Primary Myelofibrosis diagnosis
- Published
- 2009
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108. Three-dimensional dynamic time-resolved contrast-enhanced MRA using parallel imaging and a variable rate k-space sampling strategy in intracranial arteriovenous malformations.
- Author
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Petkova M, Gauvrit JY, Trystram D, Nataf F, Godon-Hardy S, Munier T, Oppenheim C, and Meder JF
- Subjects
- Adolescent, Adult, Female, Humans, Male, Reproducibility of Results, Sample Size, Sensitivity and Specificity, Signal Processing, Computer-Assisted, Young Adult, Algorithms, Image Enhancement methods, Image Interpretation, Computer-Assisted methods, Imaging, Three-Dimensional methods, Intracranial Arteriovenous Malformations pathology, Magnetic Resonance Angiography methods
- Abstract
Purpose: To evaluate the effectiveness of three-dimensional (3D) dynamic time-resolved contrast-enhanced MRA (TR-CE-MRA) using a combination of a parallel imaging technique (ASSET: array spatial sensitivity encoding technique) and a time-resolved method (TRICKS: time-resolved imaging of contrast kinetics) and to compare it with 3D dynamic TR-CE-MRA using ASSET alone in the assessment of intracranial arteriovenous malformations (AVMs)., Materials and Methods: Twenty consecutive patients with angiographically confirmed AVMs were investigated using both 3D dynamic TR-CE-MRA techniques. Examinations were compared with respect to image quality, spatial resolution, number and type of feeders and drainers, nidus size, presence of early venous filling and temporal resolution. Digital subtraction angiography was used as standard of reference., Results: The higher temporal and spatial resolution of 3D dynamic TR-CE-MRA TRICKS ASSET allowed a better assessment of intracranial vascular malformations, namely better depiction of feeders, drainers and better detection of early venous drainage. There was no significant difference between them in terms of nidus size., Conclusion: 3D dynamic TR-CE-MRA combining parallel imaging and a time-resolved method with subsecond and submillimeter resolution could become the first-line investigation technique in both diagnosis and follow-up of intracranial AVMs.
- Published
- 2009
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109. Epidermoid-cyst of the conus medullaris: usefulness of DWI.
- Author
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Piana G, Naggara O, Oppenheim C, Rodrigo S, Meder JF, Marsico R, and Page P
- Subjects
- Adult, Contrast Media, Diagnosis, Differential, Epidermal Cyst surgery, Humans, Male, Spinal Diseases surgery, Diffusion Magnetic Resonance Imaging methods, Epidermal Cyst diagnosis, Spinal Diseases diagnosis
- Published
- 2008
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110. Unruptured intracranial aneurysms: their illusive natural history and why subgroup statistics cannot provide normative criteria for clinical decisions or selection criteria for a randomized trial.
- Author
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Raymond J, Roy D, Weill A, Guilbert F, Nguyen T, Molyneux AJ, Fox AJ, Johnston SC, Cognard C, Pierot L, Meder JF, and Rouleau I
- Subjects
- Diagnostic Imaging, Humans, Intracranial Aneurysm diagnosis, Randomized Controlled Trials as Topic, Research Design, Risk Assessment, Statistics as Topic, Intracranial Aneurysm therapy
- Abstract
There is currently no evidence that treatment of unruptured aneurysms is beneficial. Confronted with the uncertainty, many clinicians are attracted by an individual calculus of risks using numbers extracted from subgroup statistics of observational studies or natural history data. The so-called natural history of unruptured aneurysms refers to a purely man-made ratio of events divided by the number of untreated patients identified by imaging, a ratio heavily influenced by referral patterns and arbitrary clinical decisions. Available studies lacked prespecified hypotheses, exposing all analyses to sampling error and bias, and sample sizes were too small to provide reliable subgroup statistics. Far from being "natural kinds" of aneurysms, subgroups were post-hoc creations. Resulting data-driven statistics can only be exploratory, the error too uncontrollable to serve for clinical decisions. A randomized trial is in order, but selection according to fixed size criteria is ill-advised, given the imprecision of imaging, the influence of other factors such as location, previous history, multiplicity of lesions, risks of treatment, age and the danger of arbitrarily excluding from a long trial a large segment of the population with aneurysms for whom the research question is most pertinent.
- Published
- 2008
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111. Language lateralization in temporal lobe epilepsy using functional MRI and probabilistic tractography.
- Author
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Rodrigo S, Oppenheim C, Chassoux F, Hodel J, de Vanssay A, Baudoin-Chial S, Devaux B, and Meder JF
- Subjects
- Adolescent, Adult, Cognition Disorders diagnosis, Cognition Disorders epidemiology, Electroencephalography, Epilepsy, Temporal Lobe epidemiology, Female, Humans, Male, Middle Aged, Neuropsychological Tests, Probability, Epilepsy, Temporal Lobe diagnosis, Epilepsy, Temporal Lobe physiopathology, Functional Laterality physiology, Language, Magnetic Resonance Imaging
- Abstract
Purpose: Language functional magnetic resonance imaging (fMRI) is used to noninvasively assess hemispheric language specialization as part of the presurgical work-up in temporal lobe epilepsy (TLE). White matter asymmetries on diffusion tensor imaging (DTI) may be related to language specialization as shown in controls and TLE. To refine our understanding of the effect of epilepsy on the structure-function relationships, we focused on the arcuate fasciculus (ArcF) and the inferior occipitofrontal fasciculus (IOF) and tested the relationship between DTI- and fMRI-based lateralization indices in TLE., Methods: fMRI with three language tasks and DTI were obtained in 20 patients (12 right and 8 left TLE). The ArcF, a major language-related tract, and the IOF were segmented bilaterally using probabilistic tractography to obtain fractional anisotropy (FA) lateralization indices. These were correlated with fMRI-based lateralization indices computed in the inferior frontal gyrus (Pearson's correlation coefficient)., Results: fMRI indices were left-lateralized in 16 patients and bilateral or right-lateralized in four. In the ArcF, FA was higher on the left than on the right side, reaching significance in right but not in left TLE. We found a positive correlation between ArcF anisotropy and fMRI-based lateralization indices in right TLE (p < 0.009), but not in left TLE patients. No correlation was observed for the IOF., Conclusions: Right TLE patients with more left-lateralized functional activations also showed a leftward-lateralized arcuate fasciculus. The decoupling between the functional and structural indices of the ArcF underlines the complexity of the language network in left TLE patients.
- Published
- 2008
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112. [Imaging of acute confusional state].
- Author
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Brami-Zylberberg F, Charbonneau F, Naggara O, Rodrigo S, Oppenheim C, Pruvo JP, and Meder JF
- Subjects
- Confusion etiology, Humans, Confusion diagnosis, Magnetic Resonance Imaging
- Published
- 2008
- Full Text
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113. [Evaluation of professional practices].
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Meder JF
- Subjects
- Humans, Health Services Research, Neuroradiography, Professional Practice organization & administration
- Published
- 2008
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114. ICONE: An International Consortium of Neuro Endovascular Centres.
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Raymond J, White P, Kallmes DF, Spears J, Marotta T, Roy D, Guilbert F, Weill A, Nguyen T, Molyneux AJ, Cloft H, Cekirge S, Saatci I, Bracard S, Meder JF, Moret J, Cognard C, Qureshi AI, Turk AS, and Berenstein A
- Abstract
Summary: The proliferation of new endovascular devices and therapeutic strategies calls for a prudentand rational evaluation of their clinical benefit. This evaluation must be done in an effective manner and in collaboration with industry. Such research initiative requires organisation a land methodological support to survive and thrive in a competitive environment. We propose the formation of an international consortium, an academic alliance committed to the pursuit of effective neurovascular therapies. Such a consortium would be dedicated to the designand execution of basic science, device developmentand clinical trials. The Consortium is owned and operated by its members. Members are international leaders in neurointerventional research and clinical practice. The Consortium brings competency, knowledge, and expertise to industry as well as to its membership across aspectrum of research initiatives such as: expedited review of clinical trials, protocol development, surveys and systematic reviews; laboratory expertise and support for research design and grant applications to public agencies. Once objectives and protocols are approved, the Consortium provides a stable network of centers capable of timely realization of clinical trials or pre clinical investigations in an optimal environment. The Consortium is a non-profit organization. The potential revenue generated from clientsponsored financial agreements will be redirected to the academic and research objectives of the organization. The Consortium wishes to work inconcert with industry, to support emerging trends in neurovascular therapeutic development. The Consortium is a realistic endeavour optimally structured to promote excellence through scientific appraisal of our treatments, and to accelerate technical progress while maximizing patients' safety and welfare.
- Published
- 2008
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115. Pulsed arterial spin labeling applications in brain tumors: practical review.
- Author
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Tourdias T, Rodrigo S, Oppenheim C, Naggara O, Varlet P, Amoussa S, Calmon G, Roux FX, and Meder JF
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- Biopsy, Brain Neoplasms blood supply, Brain Neoplasms pathology, Diagnosis, Differential, Glioma blood supply, Glioma pathology, Humans, Magnetic Resonance Imaging, Interventional, Neoplasm Staging, Spin Labels, Stereotaxic Techniques, Brain Neoplasms diagnosis, Glioma diagnosis, Magnetic Resonance Imaging methods
- Abstract
Few institutions use MRI perfusion without contrast injection called arterial spins labeling (ASL) routinely in clinical setting. After general considerations concerning the different ASL techniques and quantitative issues, we will detail a pulsed sequence that can be used on a clinical 1.5-T MR unit. We will discuss and illustrate the use of ASL in tumoral diseases for diagnosis, gliomas grading, stereotactic biopsy guidance and for follow-up after treatment.
- Published
- 2008
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116. [Structural MRI in adult partial epilepsy].
- Author
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Rodrigo S, Oppenheim C, Leclerc X, Soto-Ares G, Pruvo JP, and Meder JF
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- Brain growth & development, Brain Diseases complications, Brain Diseases pathology, Brain Injuries complications, Brain Injuries pathology, Brain Ischemia complications, Brain Ischemia pathology, Cerebral Cortex pathology, Cerebrovascular Disorders complications, Cerebrovascular Disorders pathology, Epilepsies, Partial diagnosis, Epilepsies, Partial etiology, Hippocampus pathology, Humans, Magnetic Resonance Imaging, Sclerosis, Brain pathology, Epilepsies, Partial pathology
- Abstract
Magnetic resonance imaging (MRI) is the prominent imaging modality in the field of epilepsy. MRI plays a major role in describing and recognizing the malformations of cortical development and hippocampal sclerosis and has improved epilepsy patient care. MRI is also accurate in detecting the other major epilepsy etiologies (vascular malformations and cicatricial lesions). Presurgical MRI is relevant since it provides a high-resolution study of the brain.
- Published
- 2008
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117. [New techniques of structural and functional MRI].
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Rodrigo S, Oppenheim C, Jissendi P, Soto-Ares G, Pruvo JP, and Meder JF
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- Brain pathology, Brain physiopathology, Brain Chemistry physiology, Electroencephalography, Epilepsy pathology, Epilepsy physiopathology, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging trends, Neurons physiology, Epilepsy diagnosis, Magnetic Resonance Imaging instrumentation
- Abstract
Magnetic resonance imaging is an imaging technique allowing morphological and functional study of the brain. Algorithmic and technical advances offer new insights in such brain studies using new approaches to search epileptogenic lesion. Voxel based analysis appears as the dominant methodology to study grey and white matter using the following contrast: T1, T2, T2 relaxometry, magnetization transfert and diffusion weighted imaging. Ongoing development focuses on sulcal morphometry and gyrification index, to improve our understanding of developmental epilepsy. Magnetic resonance spectroscopy appears as a promising tool following availability of high field strength clinical MRI and evidence about its utility in the field of epileptology. Functional MRI benefits from such high field strength and new pulse sequence using diffusion gradients to probe neuronal firing.
- Published
- 2008
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118. Unruptured Intracranial Aneurysms. A Critical Review of the International Study of Unruptured Intracranial Aneurysms (ISUIA) and of Appropriate Methods to Address the Clinical Problem.
- Author
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Raymond J, Guillemin F, Proust F, Molyneux AJ, Fox AJ, Claiborne JS, Meder JF, and Rouleau I
- Abstract
Summary: The preventive treatment of unruptured aneurysms has been performed for decades despite the lack of evidence of a clinical benefit. Reports of observational studies such as the International Study of Unruptured Intracranial Aneurysms (ISUIA) suggest that preventive treatments are rarely justified. Are these reports compelling enough to guide clinical practice? The ISUIA methods and data are reviewed and analysed in a more conventional manner. The design of the appropriate clinical research program is approached by steps, reviewing potential problems, from the formulation of the precise research question to the interpretation of subgroup analyses, including sample size, representativity, duration of observation period, blinding, definition of outcome events, analysis of cross-overs, losses to follow-up, and data reporting. Unruptured intracranial aneurysms observed in ISUIA ruptured at a minimal annual rate of 0.8% (0.5-1%), despite multiple methodological difficulties biased in favour of a benign natural history. Available registries do not have the power or the design capable of providing normative guidelines for clinical decisions. The appropriate method to solve the clinical dilemma is a multicentric trial comparing the incidence of a hard clinical outcome events in approximately 2000 patients randomly allocated to a treatment group and a deferred treatment group, all followed for ten years or more. Observational studies have failed to provide reliable evidence in favour or against the preventive treatment of unruptured aneurysms. A randomized trial is in order to clarify what is the role of prevention in this common clinical problem.
- Published
- 2008
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119. Radiosurgery with or without A 2-mm margin for 93 single brain metastases.
- Author
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Nataf F, Schlienger M, Liu Z, Foulquier JN, Grès B, Orthuon A, Vannetzel JM, Escudier B, Meder JF, Roux FX, and Touboul E
- Subjects
- Adult, Aged, Aged, 80 and over, Brain Neoplasms pathology, Brain Neoplasms secondary, Female, Follow-Up Studies, Humans, Magnetic Resonance Imaging, Male, Middle Aged, Radiosurgery adverse effects, Radiotherapy Dosage, Retrospective Studies, Survival Analysis, Tumor Burden, Brain Neoplasms surgery, Radiosurgery methods
- Abstract
Purpose: Retrospective comparison of Linac radiosurgery (RS) in 93 single brain metastases with or without a 2-mm margin., Patients and Methods: A total of 153 patients had Linac RS (between April 1992 and June 2004), with 139 patients (90.8%) evaluable in June 2005. Sixty-one patients (44%) had extracranial lesions and 65 patients had neurologic symptoms (47%). RS alone: 105 patients (66%); RS +whole brain radiotherapy: 34 patients (24%). Single metastasis: 93/139 patients; classic RS: 42/93 patients; 2-mm margin: 51/93 patients; 30 multiple lesions patients were excluded., Treatment: 15 Mv X-ray Linac, circular minibeams, 8-30 mm, four to six noncoplanar coronal arcs. Isodose was 60-80%; doses were 10-20 Gy., Follow-Up: 12 months-13 years; median, 14 months., Results: Local control (LC) was not improved in 51 margin patients vs. 42 classic RS patients: 1 year: 69.1% and 72.4%. Two-year LC rate: 64% and 54.7%, respectively. Survival: median classic RS: 11.3 months; margin RS, 19 months (p = 0.34) and 1 year, 41.6% and 60.2%, respectively. Margin RS patients had a significantly higher rate of severe parenchymal complications: 19.6% vs. 7.1% (p = 0.02); surgery was necessary in 4 of 51 cases vs. 1 of 42 classic RS cases., Conclusion: No increase of 1- and 2-year LC rate in margin RS or survival and median survival: 11.3 vs. 19 months (NS) 2-mm margin associated with more severe parenchymal complications (p = 0.02). This procedure is therefore not recommended. Late CT images and 1-mm margin as recommended by pathologists, use of three-dimensional magnetic resonance imaging and fuzzy method to calculate volumes may yield better results. Stereotactic hypofractionation requires further studies.
- Published
- 2008
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120. Comparison of optimized and standard diffusion-weighted imaging at 1.5T for the detection of acute lesions in patients with transient ischemic attack.
- Author
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Bertrand A, Oppenheim C, Lamy C, Rodrigo S, Naggara O, Mas JL, and Meder JF
- Subjects
- Aged, False Negative Reactions, Female, Humans, Male, Reproducibility of Results, Sensitivity and Specificity, Brain pathology, Diffusion Magnetic Resonance Imaging methods, Echo-Planar Imaging methods, Image Enhancement methods, Ischemic Attack, Transient diagnosis
- Abstract
Summary: The high rate of normal diffusion-weighted imaging (DWI) in patients with transient ischemic attack (TIA) raises the question as to its sensitivity for detecting small ischemic lesions. We compared standard and optimized DWI in 36 consecutive patients with TIA. Optimized DWI was positive in more patients than standard DWI (19 versus 16; P < .001) and showed more lesions (56 versus 42; P = .002). At 1.5T, optimizing DWI decreases the rate of false-negative DWI in patients with TIA.
- Published
- 2008
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121. Human subinsular asymmetry studied by diffusion tensor imaging and fiber tracking.
- Author
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Rodrigo S, Naggara O, Oppenheim C, Golestani N, Poupon C, Cointepas Y, Mangin JF, Le Bihan D, and Meder JF
- Subjects
- Adult, Female, Functional Laterality, Humans, Male, Reference Values, Brain anatomy & histology, Cerebral Cortex, Diffusion Magnetic Resonance Imaging
- Abstract
Background and Purpose: Our aim was to improve our understanding of the subinsular white matter microstructural asymmetries in healthy right-handed subjects. Structural brain asymmetries could be related to functional asymmetries such as hemisphere language dominance or handedness. Besides the known gray matter asymmetries, white matter asymmetries could also play a key role in the understanding of hemispheric specialization, notably that of language., Materials and Methods: White matter asymmetries were studied by diffusion tensor imaging at 1.5T (41 diffusion-gradient directions; b-value set to 700 s/mm(2); matrix, 128(2); in-plane resolution, 1.875 x 1.875 mm; section thickness, 2.0 mm) and fiber tracking (BrainVISA software). The main white matter bundles passing through the subinsular area were segmented, and fractional anisotropy (FA) was measured along each of the segmented bundles., Results: In line with published results, we found an asymmetry of the arcuate fasciculus and the subinsular white matter, namely left-greater-than-right FA in right-handed controls. Furthermore, by segmenting major tracts coursing through this region, we showed that the subinsular portions of the uncinate fasciculus (UF) and the inferior occipitofrontal fasciculus (IOF) contribute to this FA asymmetry. Those tracts have been reported to be likely implicated in the language network., Conclusion: Because the left hemisphere hosts language functions in most right-handers, the significant leftward asymmetry observed within the arcuate fasciculus, the subinsular part of the UF and IOF may be related to the hemispheric specialization for language.
- Published
- 2007
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122. Asymptomatic spontaneous acute vertebral artery dissection: diagnosis by high-resolution magnetic resonance images with a dedicated surface coil.
- Author
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Naggara O, Oppenheim C, Toussaint JF, Calvet D, Touze E, Mas JL, and Meder JF
- Subjects
- Acute Disease, Adult, Artifacts, Contrast Media, Diagnosis, Differential, Female, Humans, Aortic Dissection diagnosis, Magnetic Resonance Imaging instrumentation, Vertebral Artery
- Published
- 2007
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123. [Is an evaluation required at the third cycle?].
- Author
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Meder JF, Dacher JN, and Krausé D
- Subjects
- Clinical Competence, Curriculum standards, Education, Medical legislation & jurisprudence, European Union, France, Humans, Licensure, Medical standards, Education, Medical standards, Educational Measurement methods, Educational Measurement standards
- Published
- 2007
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124. Uncinate fasciculus fiber tracking in mesial temporal lobe epilepsy. Initial findings.
- Author
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Rodrigo S, Oppenheim C, Chassoux F, Golestani N, Cointepas Y, Poupon C, Semah F, Mangin JF, Le Bihan D, and Meder JF
- Subjects
- Adolescent, Adult, Anisotropy, Dominance, Cerebral physiology, Energy Metabolism physiology, Epilepsy, Temporal Lobe pathology, Epilepsy, Temporal Lobe physiopathology, Female, Frontal Lobe pathology, Hippocampus pathology, Hippocampus physiopathology, Humans, Male, Nerve Fibers, Myelinated pathology, Neural Pathways pathology, Neural Pathways physiopathology, Reference Values, Sclerosis, Temporal Lobe pathology, Diffusion Magnetic Resonance Imaging, Epilepsy, Temporal Lobe diagnosis, Frontal Lobe physiopathology, Image Processing, Computer-Assisted, Imaging, Three-Dimensional, Nerve Fibers, Myelinated physiology, Temporal Lobe physiopathology
- Abstract
In temporal lobe epilepsy (TLE) due to hippocampal sclerosis (HS), ictal discharge spread to the frontal and insulo-perisylvian cortex is commonly observed. The implication of white matter pathways in this propagation has not been investigated. We compared diffusion tensor imaging (DTI) measurements along the uncinate fasciculus (UF), a major tract connecting the frontal and temporal lobes, in patients and controls. Ten right-handed patients referred for intractable TLE due to a right HS were investigated on a 1.5-T MR scanner including a DTI sequence. All patients had interictal fluorodeoxyglucose PET showing an ipsilateral temporal hypometabolism associated with insular and frontal or perisylvian hypometabolism. The controls consisted of ten right-handed healthy subjects. UF fiber tracking was performed, and its fractional anisotropy (FA) values were compared between patients and controls, separately for the right and left UF. The left-minus-right FA UF asymmetry index was computed to test for intergroup differences. Asymmetries were found in the control group with right-greater-than-left FA. This asymmetrical pattern was lost in the patient group. Right FA values were lower in patients with right HS versus controls. Although preliminary, these findings may be related to the preferential pathway of seizure spread from the mesial temporal lobe to frontal and insulo-perisylvian areas.
- Published
- 2007
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125. [Diffusion tensor imaging and tractography of the brain and spinal cord].
- Author
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Oppenheim C, Ducreux D, Rodrigo S, Hodel J, Tourdias T, Charbonneau F, Pierrefitte S, and Meder J
- Subjects
- Adult, Age Factors, Aged, Alzheimer Disease diagnosis, Anisotropy, Brain Neoplasms diagnosis, CADASIL diagnosis, Diagnosis, Differential, Epilepsy diagnosis, Glioma diagnosis, Humans, Infant, Newborn, Mental Disorders diagnosis, Models, Neurological, Stroke diagnosis, Time Factors, Anatomy, Cross-Sectional, Brain anatomy & histology, Brain pathology, Brain Diseases diagnosis, Magnetic Resonance Imaging methods, Spinal Cord anatomy & histology, Spinal Cord pathology, Spinal Cord Diseases diagnosis
- Abstract
Diffusion tensor imaging is a magnetic resonance imaging technique that provides details on tissue microstructure and organization well beyond the usual image resolution. With diffusion tensor imaging, diffusion anisotropy can be quantified and subtle white matter changes not normally seen on conventional MRI can be detected. The aim of this article is to review the principles of diffusion tensor imaging and fiber tracking and their applications to the study of the brain, including Alzheimer disease, neuropsychiatric disorders, strokes, multiple sclerosis, brain tumors, and intractable seizures. Emerging applications to spinal cord disorders are also presented.
- Published
- 2007
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126. Sensory dysfunction is correlated to cerebellar volume reduction in early schizophrenia.
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Mouchet-Mages S, Canceil O, Willard D, Krebs MO, Cachia A, Martinot JL, Rodrigo S, Oppenheim C, and Meder JF
- Subjects
- Adolescent, Adult, Diagnostic and Statistical Manual of Mental Disorders, Female, Humans, Magnetic Resonance Imaging, Male, Schizophrenia diagnosis, Severity of Illness Index, Cerebellum anatomy & histology, Schizophrenia epidemiology, Schizophrenia physiopathology, Sensation Disorders diagnosis, Sensation Disorders epidemiology
- Published
- 2007
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127. Trial on endovascular treatment of unruptured aneurysms (TEAM): study monitoring and rationale for trial interruption or continuation.
- Author
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Raymond J, Meder JF, Molyneux AJ, Fox AJ, Johnston SC, Collet JP, and Rouleau I
- Subjects
- Humans, Embolization, Therapeutic, Intracranial Aneurysm therapy, Randomized Controlled Trials as Topic, Research Design
- Abstract
Preventive treatment of unruptured intracranial aneurysms is often performed but has never been proved beneficial as compared to conservative management. In a context of uncertainty, the 'best treatment' that can be offered to each individual is a chance to be treated and thus to be protected from rupture of the aneurysm, and an equal chance not to be treated, and hence to be exempted from possible immediate complications, using randomization. Such action is optimal unless or until an independent committee with privileged access to data judges that, given the comparative outcome of the 2 groups, preventive treatment or conservative management, is generally warranted. Potential reasons to interrupt such a study are reviewed, including insufficient recruitment, poor compliance, excessive cross-overs, unacceptable iatrogenia, and treatments being convincingly different or equivalent. We conclude that insufficient recruitment is the sole realistic event that could lead to premature interruption. This review may provide a deeper understanding of the principles justifying the necessity of the study.
- Published
- 2007
- Full Text
- View/download PDF
128. Management and outcome of patients with transient ischemic attack admitted to a stroke unit.
- Author
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Calvet D, Lamy C, Touzé E, Oppenheim C, Meder JF, and Mas JL
- Subjects
- Adult, Aged, Anticoagulants therapeutic use, Carotid Arteries surgery, Diffusion Magnetic Resonance Imaging, Female, Health Status Indicators, Heparin therapeutic use, Humans, Ischemic Attack, Transient complications, Ischemic Attack, Transient diagnosis, Ischemic Attack, Transient mortality, Male, Middle Aged, Paris epidemiology, Patient Admission statistics & numerical data, Platelet Aggregation Inhibitors therapeutic use, Predictive Value of Tests, Proportional Hazards Models, Risk Assessment, Risk Factors, Stroke diagnosis, Stroke etiology, Stroke mortality, Time Factors, Treatment Outcome, Vascular Surgical Procedures statistics & numerical data, Hospital Units statistics & numerical data, Ischemic Attack, Transient therapy, Stroke prevention & control
- Abstract
Background: The way in which patients with transient ischemic attack (TIA) are investigated and treated varies substantially worldwide. There are no data on the management and outcome of TIA patients admitted to a stroke unit. We assessed to what extent rapid management of TIA patients admitted to a stroke unit led to specific treatments which can prevent stroke and evaluated the early risk and predictors of stroke in these patients., Methods: From January 2003 to November 2005, 203 consecutive patients with a recent (<48 h) TIA were admitted to our stroke unit. All patients had a diffusion-weighted imaging (DWI) on admission, a standardized etiological workup, and were followed up to 3 months., Results: The median (interquartile range) time from TIA onset to admission to the stroke unit was 12 h (5-25). DWI revealed acute lesions in 64 patients (32%). Of the 203 patients, 147 (72%) were treated by antiplatelet therapy and 56 (28%) with high doses of heparin, soon after their admission. In addition, 7 patients (3%) had a carotid revascularization. The risk of stroke was 2.5% (95% CI, 0.3-4.7) at 1 week, and 3.5% (1.0-6.1) at 3 months. In multivariate analysis, a score > or =5 at the previously validated ABCD score (HR = 5.0; 1.0-25.8; p = 0.06) and the presence of DWI abnormalities (HR = 10.3; 1.2-86.7; p = 0.03) were independent predictors of stroke at 3 months., Conclusion: Early management of TIA in a stroke unit leads to specific treatments in a significant proportion of cases. The presence of acute lesions on DWI and the ABCD score predict the 3-month risk of stroke after TIA.
- Published
- 2007
- Full Text
- View/download PDF
129. [Diffusion-weighted imaging of the brain: normal patterns, traps and artifacts].
- Author
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Bertrand A, Oppenheim C, Moulahi H, Naggara O, Rodrigo S, Patsoura S, Adamsbaum C, Pierrefitte S, and Meder JF
- Subjects
- Humans, Artifacts, Brain anatomy & histology, Diffusion Magnetic Resonance Imaging
- Abstract
Owing to its rapid acquisition time and high sensitivity, diffusion-weighted imaging has turned into a routine sequence for brain imaging. This is the case not only for stroke, but also for various diseases such as abscesses or tumors. Being aware of the artifacts is important for optimal interpretation. After a brief review of the normal patterns, the most frequent artifacts, inherent to the echoplanar imaging technique, are described and we provide suggestions to avoid them. Most current traps are caused by T2-weighting of the diffusion images; the key for avoiding erroneous interpretation relies on the ADC map.
- Published
- 2006
- Full Text
- View/download PDF
130. [Imaging of acute stroke].
- Author
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Naggara O, Hamon M, Oppenheim C, Rodrigo S, Leclerc X, Pruvo JP, and Meder JF
- Subjects
- Acute Disease, Adult, Humans, Middle Aged, Thrombolytic Therapy, Tomography, X-Ray Computed, Brain Ischemia diagnostic imaging, Cerebral Hemorrhage diagnostic imaging, Stroke diagnostic imaging
- Abstract
Acute stroke patients represent an important diagnostic and therapeutic challenge. Patients with brain damage in the ischemic, but not yet infarcted, phase have the greatest potential for recovery. Here we review the most commonly employed diagnostic tools that are currently used before stroke therapy. While computed tomography is pertinent to differentiate ischemic from hemorrhagic stroke, this technique cannot be used as an etiological screening too. The ischemic origin of symptoms can be confirmed with magnetic resonance imaging which also contributes to for therapeutic decision making, prognosis assessment and etiological screening.
- Published
- 2006
- Full Text
- View/download PDF
131. [Congenital absence of a cervical pedicle].
- Author
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Tourdias T, Charbonneau F, Hodel J, Rodrigo S, and Meder JF
- Subjects
- Female, Humans, Middle Aged, Cervical Vertebrae abnormalities, Spinal Dysraphism pathology
- Published
- 2006
- Full Text
- View/download PDF
132. Unruptured intracranial aneurysms: the unreliability of clinical judgment, the necessity for evidence, and reasons to participate in a randomized trial.
- Author
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Raymond J, Meder JF, Molyneux AJ, Fox AJ, Johnston SC, Collet JP, and Rouleau I
- Subjects
- Humans, Intracranial Aneurysm complications, Patient Selection, Randomized Controlled Trials as Topic, Reproducibility of Results, Risk Assessment, Subarachnoid Hemorrhage etiology, Subarachnoid Hemorrhage prevention & control, Treatment Outcome, Intracranial Aneurysm therapy
- Published
- 2006
- Full Text
- View/download PDF
133. [Brain imaging patterns after stroke].
- Author
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Oppenheim C, Lamy C, Mas JL, and Meder JF
- Subjects
- 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
- Abstract
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.
- Published
- 2006
134. [Imaging of intracranial metastases in adults].
- Author
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Naggara O, Brami-Zylberberg F, Rodrigo S, Raynal M, Meary E, Godon-Hardy S, Oppenheim C, and Meder JF
- Subjects
- Aged, Diagnosis, Differential, Humans, Magnetic Resonance Imaging, Male, Tomography, X-Ray Computed, Brain Neoplasms diagnosis, Brain Neoplasms secondary
- Abstract
Intracranial metastases account for up to 35% of intracranial tumors in adult. They can involve any part of the central nervous system: brain, meninges and cranial nerves. Any systemic tumor can metastasize to the brain; the most common primaries include lung, breast and melanoma. Imaging plays a major role in the evaluation and management of patients with metastatic brain tumors. This article discusses optimal CT and MR imaging protocols and describes imaging features and distinguishing characteristics of cerebral and meningeal metastases.
- Published
- 2006
- Full Text
- View/download PDF
135. Perfusion-weighted MR imaging studies in brain hypervascular diseases: comparison of arterial input function extractions for perfusion measurement.
- Author
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Ducreux D, Buvat I, Meder JF, Mikulis D, Crawley A, Fredy D, TerBrugge K, Lasjaunias P, and Bittoun J
- Subjects
- Adolescent, Adult, Child, Female, Humans, Male, Middle Aged, Prospective Studies, Blood Volume, Cerebrovascular Circulation, Cerebrovascular Disorders diagnosis, Cerebrovascular Disorders physiopathology, Magnetic Resonance Angiography
- Abstract
Background and Purpose: Brain hypervascular diseases are complex and induce hemodynamic disturbances on brain parenchyma, which are difficult to accurately evaluate by using perfusion-weighted (PWI) MR imaging. Our purpose was to test and to assess the best AIF estimation method among 4 patients with brain hypervascular disease and healthy volunteers., Methods: Thirty-three patients and 10 healthy volunteers underwent brain perfusion studies by using a 1.5T MR imaging scanner with gadolinium-chelate bolus injection. PWI was performed with the indicator dilution method. AIF estimation methods were performed with local, regional, regional scaled, and global estimated arterial input function (AIF), and PWI measurements (cerebral blood volume [CBV] and cerebral blood flow [CBF]) were performed with regions of interest drawn on the thalami and centrum semiovale in all subjects, remote from the brain hypervascular disease nidus. Abnormal PWI results were assessed by using Z Score, and evaluation of the best AIF estimation method was performed by using a no gold standard evaluation method., Results: From 88% to 97% of patients had overall abnormal perfusion areas of hypo- (decreased CBV and CBF) and/or hyperperfusion (increased CBV and CBF) and/or venous congestion (increased CBV, normal or decreased CBF), depending on the AIF estimation method used for PWI computations. No gold standard evaluation of the 4 AIF estimates found the regional and the regional scaled methods to be the most accurate., Conclusion: Brain hypervascular disease induces remote brain perfusion abnormalities that can be better detected by using PWI with regional or regional scaled AIF estimation methods.
- Published
- 2006
136. [Cerebral venous and sinus thrombosis].
- Author
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Zuber M and Meder JF
- Subjects
- 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.
- Published
- 2006
137. Diffusion tensor imaging in early Alzheimer's disease.
- Author
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Naggara O, Oppenheim C, Rieu D, Raoux N, Rodrigo S, Dalla Barba G, and Meder JF
- Subjects
- Age Factors, Aged, Aged, 80 and over, Anisotropy, Cognition Disorders diagnosis, Female, Frontal Lobe pathology, Humans, Male, Neuropsychological Tests, Occipital Lobe pathology, Temporal Lobe pathology, Alzheimer Disease pathology, Brain pathology, Diffusion Magnetic Resonance Imaging methods
- Abstract
Our aim was to investigate the extent of white matter tissue damage in patients with early Alzheimer disease (AD) using diffusion tensor magnetic resonance imaging (DTI). Although AD pathology mainly affects cortical grey matter, previous magnetic resonance imaging (MRI) studies showed that changes also exist in the white matter (WM). However, the nature of AD-associated WM damage is still unclear. Conventional and DTI examinations (b=1000 s/mm(2), 25 directions) were obtained from 12 patients with early AD (Mini Mental State Examination [MMSE] score=27, Grober and Buschke test score=33.2, digit span score=5.6) and 12 sex- and age-matched volunteers. The right and left mean diffusivity (MD) and fractional anisotropy (FA) of several WM regions were pooled in each patient and control, and compared between the two groups. Volumes of the whole brain and degree of atrophy of the temporal lobe were compared between the two groups. In AD, MD was increased in the splenium of the corpus callosum and in the WM in the frontal and parietal lobes. FA was bilaterally decreased in the WM of the temporal lobe, the frontal lobe and the splenium compared with corresponding regions in controls. Values in other areas (occipital area, superior temporal area, cingulum, internal capsule, and genu of the corpus callosum) were not different between patients and controls. No correlations were found between the MMSE score and the anisotropy indices. Findings of DTI reveal abnormalities in the frontal and temporal WM in early AD patients. These changes are compatible with early temporal-to-frontal disconnections.
- Published
- 2006
- Full Text
- View/download PDF
138. [Cervical arteries dissection: diagnostic Color Doppler US criteria at the acute phase].
- Author
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Gobin-Metteil MP, Oppenheim C, Domigo V, Trystram D, Brami-Zylberberg F, Naggara O, and Meder JF
- Subjects
- Acute Disease, Adult, Female, Humans, Male, Middle Aged, Neck, Retrospective Studies, Aortic Dissection diagnostic imaging, Carotid Artery Diseases diagnostic imaging, Ultrasonography, Doppler, Color, Vertebral Artery Dissection diagnostic imaging
- Abstract
Purpose: To estimate the value of duplex color-coded ultrasonography in the initial diagnosis of acute cervical artery dissection., Material and Method: Retrospective study of 31 patients, mean age 45, sex ratio=1, referred for clinical suspicion of cervical artery dissection, confirmed by MRI. 46 dissected arteries were imaged. Ten patients presented multiple dissections. The evaluated sonographic diagnostic criteria were the direct signs of intra-mural hematoma: localized increased diameter of the artery, narrowed lumen, hypo and/or isoechoic intra-mural hematoma, intimal flap. The associated criteria studied were: the location of intra-mural hematoma and in case of an occlusion, the dissection of an other artery., Results: We analyzed separately the arterial segments visualized in B-mode ultrasound (supra-bulbar internal carotid artery, vertebral artery from V0 to V3) and the arterial segments evaluated only by pulsed Doppler (intrapetrosal carotid artery, V3-V4 of the vertebral artery). With the above criteria, on arterial segments visualized in B-mode ultrasound, the diagnosis of dissection was done in 83% of cases during the initial examination but in only 30% of the arterial segments non visualized on ultrasonography., Conclusion: The direct signs of intra-mural hematoma on internal carotid and vertebral segments imaged by B-mode ultrasonography have a good sensitivity. Because results were compared to MRI, the specificity could not be assessed. In case of occlusion of an artery, multiple dissections are a strong argument for the diagnosis.
- Published
- 2006
- Full Text
- View/download PDF
139. Three-dimensional dynamic magnetic resonance angiography for the evaluation of radiosurgically treated cerebral arteriovenous malformations.
- Author
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Gauvrit JY, Oppenheim C, Nataf F, Naggara O, Trystram D, Munier T, Fredy D, Pruvo JP, Roux FX, Leclerc X, and Meder JF
- Subjects
- Adult, Aged, Cerebral Angiography, Female, Humans, Image Processing, Computer-Assisted, Intracranial Arteriovenous Malformations surgery, Male, Middle Aged, Radiosurgery, Sensitivity and Specificity, Imaging, Three-Dimensional, Intracranial Arteriovenous Malformations pathology, Magnetic Resonance Angiography methods
- Abstract
We assessed the value of three-dimensional (3D) dynamic magnetic resonance angiography (MRA) for the follow-up of patients with radiosurgically treated cerebral arteriovenous malformations (AVMs). Fifty-four patients with cerebral AVMs treated by radiosurgery (RS) were monitored using conventional catheter angiography (CCA) and 3D dynamic MRA with sensitivity encoding based on the parallel imaging. Cerebral AVM was qualitatively classified by two radiologists into one of five categories in terms of residual nidus size and persistence of early draining vein (I, >6 cm; II, 3-6 cm; III, <3 cm; IV, isolated early draining vein; V, complete obliteration). 3D MRA findings showed a good agreement with CCA in 40 cases (kappa=0.62). Of 23 nidus detected on CCA, 3D dynamic MRA showed 14 residual nidus. Of 28 occluded nidus on 3D dynamic MRA, 22 nidus were occluded on CCA. The sensitivity and specificity of 3D dynamic MRA for the detection of residual AVM were 81% and 100%. 3D dynamic MRA after RS may therefore be useful in association with MRI and can be repeated as long as opacification of the nidus or early venous drainage persists, one CCA remaining indispensable to affirm the complete occlusion at the end of follow-up.
- Published
- 2006
- Full Text
- View/download PDF
140. [Cerebral arterial infarction and diffusion tensor imaging].
- Author
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Rodrigo S, Oppenheim C, Touze E, Lamy C, Domigo V, Naggara O, Mas JL, Fredy D, and Meder JF
- Subjects
- Adult, Aged, Anisotropy, Female, Humans, Male, Middle Aged, Sensitivity and Specificity, Cerebral Infarction pathology, Diffusion Magnetic Resonance Imaging methods
- Abstract
Purpose: Diffusion-weighted imaging (3 directions) and diffusion tensor imaging (9 directions) were compared for their sensitivity to detect ischemic lesion., Materials and Methods: 41 patients (18 supposed transient ischemic attacks, 23 arterial stroke, MRI
- Published
- 2006
- Full Text
- View/download PDF
141. [Vascular tumours and malformation of the orbit].
- Author
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Naggara O, Koskas P, Lafitte F, Heran F, Piekarski JD, Meder JF, and Berges O
- Subjects
- Aneurysm classification, Aneurysm diagnosis, Arteriovenous Fistula classification, Arteriovenous Fistula diagnosis, Carotid Artery, Internal abnormalities, Cavernous Sinus abnormalities, Hemangioma, Capillary classification, Hemangioma, Capillary diagnosis, Hemangioma, Cavernous classification, Hemangioma, Cavernous diagnosis, Hemangiopericytoma classification, Hemangiopericytoma diagnosis, Humans, Intracranial Arteriovenous Malformations classification, Intracranial Arteriovenous Malformations diagnosis, Lymphangioma classification, Lymphangioma diagnosis, Orbital Neoplasms diagnosis, Peripheral Vascular Diseases classification, Peripheral Vascular Diseases diagnosis, Varicose Veins classification, Varicose Veins diagnosis, Vascular Neoplasms diagnosis, Diagnostic Imaging, Orbit blood supply, Orbital Neoplasms classification, Vascular Neoplasms classification
- Abstract
Vascular diseases are an important part of orbital pathology. We describe vascular tumours of the orbit and vascular diseases with repercussion on the orbit, from intra or extra orbital origin. The classification of these abnormalities is difficult and several terms are used to describe the same histological entity. The objective of this work is, using the current classification, to illustrate the different imaging aspects of the most frequent vascular diseases of the orbit.
- Published
- 2006
- Full Text
- View/download PDF
142. [Inflammatory presentation of a cavernous dural fistula: diagnosis with color and pulse Doppler imaging].
- Author
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Naggara O, Koskas P, Mounayer C, Heran F, Piekarski JD, Meder JF, and Bergès O
- Subjects
- Central Nervous System Vascular Malformations complications, Humans, Inflammation etiology, Male, Middle Aged, Vascular Fistula complications, Cavernous Sinus, Central Nervous System Vascular Malformations diagnostic imaging, Ultrasonography, Doppler, Color, Ultrasonography, Doppler, Pulsed, Vascular Fistula diagnostic imaging
- Abstract
We report a case of a cavernous dural fistula in a 54-year-old man the source of inflammatory ocular symptoms. Poorly adapted treatment with corticosteroids led to iatrogenic complications. We will attempt to show the advantage of color Doppler imaging for the diagnosis of this infrequent lesion. The only indication of digitalized angiography is for endovascular treatment.
- Published
- 2006
- Full Text
- View/download PDF
143. [Neuroimaging characteristics of cerebral infarcts].
- Author
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Hamon M, Oppenheim C, Leclerc X, Gauvrit JY, Pruvo JP, and Meder JF
- Subjects
- Acute Disease, Brain blood supply, Cerebrovascular Circulation physiology, Humans, Time Factors, Brain diagnostic imaging, Brain pathology, Brain Ischemia diagnosis, Magnetic Resonance Imaging, Tomography, X-Ray Computed
- Abstract
Over the last years, technical advances in neuroimaging have allowed drastic improvements in the assessment of acute ischemic cerebral events. Beyond conventional morphological analysis, diffusion-weighted and perfusion-weighted MRI now enable routine functional assessment of brain tissue; spectroscopy and diffusion tensor imaging still remains in the domain of clinical research. During acute ischemia events, diffusion-weighted MRI can detect the movements of water molecules and cytotoxic edema related to cell injury enabling rapid diagnosis and early assessment of cerebral ischemia. In conjunction with perfusion imaging, which detects hypoperfusion areas, diffusion-weighted MRI provides a means to identify areas of penumbra ischemia. More recent multislice computed tomographic (CT) scans with multimodal analysis are also very competitive for assessment of cerebral ischemia (non-enhanced CT, CT angiography and perfusion CT). The purpose of this paper is to describe the CT and MRI patterns during the different stages of cerebral infarcts.
- Published
- 2005
- Full Text
- View/download PDF
144. [Neuroimaging characteristics of intracerebral haematoma].
- Author
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Hamon M, Leclerc X, Oppenheim C, Gauvrit JY, Meder JF, and Pruvo JP
- Subjects
- Cerebral Hemorrhage etiology, Hematoma etiology, Humans, Cerebral Hemorrhage diagnosis, Hematoma diagnosis, Magnetic Resonance Imaging, Tomography, X-Ray Computed
- Abstract
The objective of brain imaging is to identify the hematoma according to its different stages and to find a potential underlying cause because of the risk of recurrence and the possibilities of treatment. In emergency, the diagnosis of hematoma is often obtained by CT scan, however today MRI has proved to be more accurate than CT to detect hemorrhage and to identify an underlying etiology. In some cases, according to the patient age, the medical history and the location of the hematoma, it may be necessary to perform a conventional angiography in order to exclude an intracranial vascular malformation. The aim of this review is to detail the different aspects of intracerebral hemorrhages according to the sequences and the temporal evolution, and to describe special findings which can help to identify an underlying etiology.
- Published
- 2005
- Full Text
- View/download PDF
145. Suprasellar paraganglioma: a case report and review of the literature.
- Author
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Naggara O, Varlet P, Page P, Oppenheim C, and Meder JF
- Subjects
- Cerebral Angiography, Humans, Male, Middle Aged, Paraganglioma surgery, Pituitary Neoplasms surgery, Sella Turcica pathology, Magnetic Resonance Imaging, Paraganglioma diagnosis, Pituitary Neoplasms diagnosis
- Abstract
Paragangliomas arising in the suprasellar region are extremely rare. We report a case of suprasellar paraganglioma in a 47-year-old man who presented with amnesia and impaired visual acuity without any endocrine dysfunction. Magnetic resonance imaging (MRI) showed a large enhancing tumour in the suprasellar area. Following subtotal surgical excision, the diagnosis of paraganglioma was confirmed by pathology. In this case report we describe the MRI pattern of suprasellar paraganglioma and review the literature of this uncommon lesion.
- Published
- 2005
- Full Text
- View/download PDF
146. [MRI of acute ischemic stroke].
- Author
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Oppenheim C, Naggara O, Arquizan C, Brami-Zylberberg F, Mas JL, Meder JF, and Frédy D
- Subjects
- Cerebral Hemorrhage diagnosis, Diffusion Magnetic Resonance Imaging, Hematoma diagnosis, Humans, Stroke drug therapy, Thrombolytic Therapy, Magnetic Resonance Imaging methods, Stroke diagnosis
- Abstract
The advent of new MR techniques such as perfusion and diffusion weighted imaging has revolutionized diagnostic imaging in stroke. In some institutions, MRI is used as the sole screening imaging technique for acute stroke patients. In this document, the authors will review the MR pattern of acute ischemic arterial stroke, highlight the usefulness of MRI for the identification of acute hematomas and stroke like episodes, present the potential use of MRI in the management of acute stroke patients, especially when thrombolysis is contemplated, and discuss the role of MRI for imaging transient ischemic attack.
- Published
- 2005
- Full Text
- View/download PDF
147. [MRI for oligodendrogliomas].
- Author
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Brami-Zylberberg F, Grand S, Le Bas JF, and Meder JF
- Subjects
- Brain Neoplasms radiotherapy, Brain Neoplasms surgery, Brain Stem radiation effects, Brain Stem surgery, Cerebral Hemorrhage pathology, Diagnosis, Differential, Diffusion Magnetic Resonance Imaging, Humans, Meningeal Neoplasms radiotherapy, Meningeal Neoplasms surgery, Neoplasm Invasiveness pathology, Neoplasm Staging, Oligodendroglioma radiotherapy, Oligodendroglioma surgery, Temporal Lobe pathology, Temporal Lobe radiation effects, Temporal Lobe surgery, Brain Neoplasms pathology, Brain Stem pathology, Meningeal Neoplasms pathology, Oligodendroglioma pathology
- Abstract
MRI has dramatically improved the management of cerebral tumors and consequently oligodendrogliomas. T1 and T2-weighted images and gadolinium enhancement are very useful for tumor detection and characterization. Tumor enhancement is of a great prognostic value because it is highly predictive of high-grade oligodendroglioma. Three-dimensional MR images provide, with high precision, the anatomical location and the relationships with functional structures (motor and language areas). The recent technical progress in MRI and the use of diffusion images in the screening of tumors lead to a better definition of the lesion. Comparative analysis of MRI images is helpful to detect eventual relapse and adverse effects of treatment.
- Published
- 2005
- Full Text
- View/download PDF
148. [Diagnosis and follow-up of cervical arterial dissections--results of the SFNV-SFNR study].
- Author
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Charbonneau F, Gauvrit JY, Touze E, Moulin T, Bracard S, Leclerc X, Mas JL, and Meder JF
- Subjects
- Follow-Up Studies, Humans, Radiography statistics & numerical data, Retrospective Studies, Carotid Artery, Internal, Dissection diagnostic imaging, Vertebral Artery Dissection diagnostic imaging
- Abstract
Introduction: the objective of this study was to determine the role of radiological techniques in the diagnosis, assessment of severity and follow-up of cervical arterial dissections., Material and Methods: from 1995 to 2001 a multicentre retrospective study was conducted in 24 hospital centers. A multiple-choice questionnaire was sent to each center in order to collect clinical information and imaging details regarding the diagnosis and follow-up of cervical arterial dissections., Results: information was gathered on 459 patients, comprising a total of 384 carotid artery dissections and 170 vertebral artery dissections. A mean of 4.85 diagnostic examinations per patient were conducted. Morphological imaging of the brain by CT or by MRI was performed on all except 3 patients. Cervical Doppler ultrasound examination was the most frequently performed test throughout the entire study period (performed in 87% of patients). Conventional arteriography was a routinely employed test in 1995 whereas by 2001 it comprised only 31.2% of requested examinations, having been progressively replaced by MRI and MRA scanning, which comprised 60% of all examinations performed by 2001. A combination of cervical Doppler ultrasonography, axial MRI and MRA of the neck vessels were performed in 39.6% of patients in 2001. Examination of the intracranial vessels was performed by transcranial Doppler ultrasound in 40% of cases and by MRA in 30% of cases. For the follow-up of arterial dissections, an average of 1.4 examinations was performed per patient. The majority of such follow-up examinations comprised Doppler ultrasound and/or MRA of the neck arteries., Conclusion: The imaging diagnosis and follow-up of cervical arterial dissections will increasingly rely on non-invasive imaging techniques.
- Published
- 2005
- Full Text
- View/download PDF
149. Serial diffusion and perfusion-weighted MR in transient hypoglycemia.
- Author
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Cordonnier C, Oppenheim C, Lamy C, Meder JF, and Mas JL
- Subjects
- Adult, Brain Ischemia diagnosis, Brain Ischemia etiology, Brain Ischemia physiopathology, Diffusion Magnetic Resonance Imaging, Female, Humans, Hypoglycemia diagnosis, Hypoglycemia physiopathology, Insulinoma diagnosis, Insulinoma physiopathology, Internal Capsule metabolism, Internal Capsule pathology, Internal Capsule physiopathology, Nerve Fibers, Myelinated metabolism, Nerve Fibers, Myelinated pathology, Pancreas pathology, Pancreas physiopathology, Pancreas surgery, Pancreatic Neoplasms diagnosis, Pancreatic Neoplasms physiopathology, Paresis diagnosis, Paresis physiopathology, Pyramidal Tracts metabolism, Pyramidal Tracts pathology, Pyramidal Tracts physiopathology, Recovery of Function, Seizures etiology, Seizures physiopathology, Treatment Outcome, Hypoglycemia complications, Insulinoma complications, Pancreatic Neoplasms complications, Paresis etiology
- Published
- 2005
- Full Text
- View/download PDF
150. Three-dimensional dynamic MR digital subtraction angiography using sensitivity encoding for the evaluation of intracranial arteriovenous malformations: a preliminary study.
- Author
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Gauvrit JY, Leclerc X, Oppenheim C, Munier T, Trystram D, Rachdi H, Nataf F, Pruvo JP, and Meder JF
- Subjects
- 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.
- Published
- 2005
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