Daniel Frédy

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BACKGROUND AND PURPOSE Hyperintense vessel sign (HVS) on fluid-attenuated inversion recovery (FLAIR) has been described in hyperacute stroke patients with arterial occlusion. We sought to determine whether HVS was more frequent in patients with intracerebral arterial stenoses than in those without stenosis regardless of the presence of a brain infarct. (More)
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(More)
PURPOSE To evaluate CT and MRI features and long term imaging follow-up of a large series of dysembryoplastic neuroepithelial tumors (DNTS). PATIENTS AND METHODS We retrospectively analyzed CT (100%) and MR imaging (83%) findings of 53 patients with complex (n = 14), simple (n = 6) or non specific histological forms (n = 33) of DNTS. All patients(More)
Several diseases may cause non-specific MR signal abnormalities of the bilateral basal ganglia and thalami. As such, diagnosis of the underlying etiology may be difficult to achieve at imaging. In this review, we will present interpretative guidelines based on clinical data (mode of presentation, previous history, clinical symptoms, and evolution) and(More)
PURPOSE to explore with functional MRI cerebral areas involved in musical and lyrical sounds signal processing with the mental imagery method. MATERIAL and METHODS nine volunteers (mean age: 27 years old) underwent functional MRI with BOLD contrast at 1.5 T. Box-car paradigms of partial recollections of musical or lyrical memories tasks were performed.(More)
We describe two original cases of internal carotid artery dysgenesis associated with a malformative spectrum, which includes transsphenoidal encephalocele, optic nerve coloboma, hypopituitarism, and hypertelorism. Cephalic neural crest cells migrate to various regions in the head and neck where they contribute to the development of structures as diverse as(More)
Dissecting aneurysms of the intracranial vertebral artery represent a more frequently recognized cause of subarachnoid hemorrhage. The poor natural history of the ruptured dissecting aneurysms indicate a surgical or endovascular treatment. Endovascular treatment usually consists of balloon occlusion of the vertebral artery. This treatment however can lead(More)
PURPOSE Symptomatic hemorrhagic transformation is a severe complication of acute ischemic stroke which occurs at a higher frequency after thrombolysis. The present study was designed to analyze whether early DWI can be used for predicting the risk of hemorrhagic transformation with clinical worsening in MCA stroke patients. MATERIALS AND METHODS Of 28(More)
Embolization is an important therapeutic tool for the treatment of cerebral arteriovenous malformations and is a part of the therapeutic strategy. In selected cases, it may lead to a total and permanent cure per se, but in most cases it will be an adjunctive therapy to radiosurgery. The authors review techniques of embolization, perioperative care,(More)