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X Leclerc

Publications and source records attributed to X Leclerc.

At least 37 records · Page 2Linked to original sources
PubMed2004

[Cerebral arteriovenous malformations: value of the non invasive vascular imaging techniques].

Imaging evaluation of cerebral arteriovenous malformations (AVM) requires selective visualization of the different compartments of the malformation in order to select the therapeutic management. Conventional angiography remains the reference to analyze intracranial vessel conspicuity but non-invasive methods constitute an excellent alternative. Among these techniques, CT angiography is rarely used because of the need to inject iodinated contrast material and because of irradiation. MR angiography provides useful information and can be performed using several techniques: time of flight with or without contrast material injection, phase contrast, three-dimensional (3D) gradient echo acquisition after contrast material injection and, more recently, MR digital subtraction angiography. The purpose of this review article is to summarize the different non-invasive techniques for vascular imaging and to analyze the usefulness of these techniques for the assessment of brain AVMs.

Angiography, Digital Subtraction↗
PubMed2003

Impairment of endothelial function in patients with spontaneous cervical artery dissection: evidence for a general arterial wall disease.

BACKGROUND AND PURPOSE: Cervical artery dissection (CAD) accounts for 10-20% of ischemic strokes in young adults. Although trauma and preexisting disorders of the arterial wall are the main predisposing factors, most CADs are considered 'spontaneous'. We hypothesized that CAD could originate in systemic vascular disease bound to the intima-media interface without clinical signs. If this hypothesis is true, endothelium-dependent vasodilation would be impaired in response to a physiological stimulus such as an increase in blood flow. METHODS: Flow-mediated arterial dilation was studied in 65 consecutive patients with spontaneous CAD: 26 with carotid artery dissection (ICAD), and 39 with vertebral artery dissection (VAD). CAD patients with vascular risk factors, trivial or obvious cervical trauma, or connective tissue disease were excluded. Twenty-three patients with ischemic stroke of unknown cause were included as controls. Using high-resolution ultrasonography, brachial artery diameter was measured at rest, during post-ischemic hyperemia (flow-mediated endothelium-dependent dilation), and after sublingual glyceryl trinitrate spray (endothelium-independent dilation). RESULTS: The mean +/- SD values of the flow-mediated vasodilation index were 5.7 +/- 6.2% in ICAD, 5.0 +/- 9.3% in VAD and 13.2 +/- 6.5% in controls (p < 0.0005), without any difference between ICAD and VAD. Endothelium-independent dilation mean values were 21.5 +/- 9.5% in ICAD, 25.1 +/- 12.5% in VAD, and 20.8 +/- 8.4% in controls, without a significant difference between groups (p = 0.49). CONCLUSIONS: These results give evidence of impaired endothelium-dependent vasodilation in CAD patients that is not the result of stroke, and suggest that an underlying abnormality of the arterial wall layers may predispose to CAD.

Adult↗
PubMed2003

Angioplasty and stenting for high-grade internal carotid artery stenosis: safety study in 39 selected patients.

BACKGROUND: Carotid angioplasty and stenting (CAS) is sometimes used as an alternative to surgery, despite the lack of evidence for its safety and efficacy. METHOD: Over a 33-month period, 39 consecutive patients with a stenosis >/=70% underwent CAS (4 in a randomized trial and 35 because of contra-indications for surgery). RESULTS: In 5 patients (13%; 95% CI: 3-23), a major complication occurred (3 disabling ischaemic strokes, 1 myocardial infarction, 1 acute interstitial nephropathy). In 7 patients (18%; 95% CI: 6-30), a minor complication occurred (5 transient ischaemic attacks, 1 transient confusional state, 1 non-disabling ischaemic stroke). CONCLUSION: CAS cannot be considered as a routine procedure and should be restricted to high-risk patients unfit for surgery.

Adult↗
PubMed2003

Percutaneous transluminal angioplasty of proximal vertebral artery stenosis: long-term clinical follow-up of 16 consecutive patients.

We report long-term (average 30 months) clinical and radiological follow-up of 16 consecutive patients with uni- or bilateral proximal vertebral artery stenosis who underwent percutaneous transluminal angioplasty (PTA), without stenting, between 1995 and 1998. Assessment was performed by an independent neurologist. All patients but one remained asymptomatic during follow-up; moderate restenosis was observed in four. PTA of the proximal vertebral artery is safe but in the absence of knowledge of the natural history of atherosclerotic vertebral artery stenosis, whether it is beneficial or not remains unproven. The decision as to whether to perform this procedure is individual.

Adult↗
PubMed2003

Giant aneurysms of the internal carotid artery: endovascular treatment and long-term follow-up.

We report the long-term follow-up of 18 patients with giant aneurysms of the internal carotid artery (ICA) referred for endovascular occlusion of the parent vessel. There were 10 aneurysms involving the infra- and/or supraclinoid cavernous segment, six the ophthalmic segment, one the petrous segment and one the bifurcation. One patient who did not tolerate test occlusion was treated medically. Clinical and imaging follow-up were obtained in 16 patients for a mean of 30 months, range 6-80 months. Endovascular treatment led to excellent clinical outcome in 16 patients. One 34-year-old woman, who presented with subarachnoid haemorrhage (SAH), died from bilateral middle cerebral artery infarcts due to severe vasospasm 4 days after treatment. The patient treated medically died from SAH. Long-term imaging follow-up in 16 patients revealed a markedly smaller aneurysm sac in all cases.

Adult↗
PubMed2003

Cerebral venous thrombosis 3-year clinical outcome in 55 consecutive patients.

An early diagnosis and heparin therapy have contributed to a decreased mortality in cerebral venous thrombosis (CVT). However, predictors of outcome are difficult to identify, because most studies suffered heterogeneity in diagnostic findings and treatments, retrospective design, and recruitment bias. The aim of this study was to evaluate the clinical outcome in 55 consecutive patients with CVT admitted over a 4-year period. The study population consisted of 42 women and 13 men, with a median age of 39 years (range 16-68). The diagnosis was performed with MRI in 53 patients, and angiography in 2. The outcome was assessed with the modified Rankin scale (mRs). After a median follow-up of 36 months (range: 12-60), 45 patients were independent (mRS 0-2), and 10 were dependent or dead (mRS 3-6). Of 48 survivors, 7 had seizures, 6 motor deficits, 5 visual field defects, 29 headache (migraine in 14, tension headache in 13, other in 2). The logistic regression analysis found focal deficits and cancer at time of diagnosis, as independent predictors of dependence or death at year 3, and isolated intra-cranial hypertension as an independent predictor of survival and independence. Mortality rates are low in the absence of cancer and focal deficits, and more than 80 % of survivors are independent after 3 years. However, 3/4 of survivors have residual symptoms. Therefore, despite a low mortality rate, CVT remains a serious disorder.

Adult↗
PubMed2003

[Sub-acute phase of cerebral ischemia: value of MRI].

MRI is the examination of choice for the evaluation of ischemic brain injury. At the acute phase, this examination may differentiate infarcted tissue from hypoperfused tissue. At the subacute phase, MRI allows to confirm the diagnosis of ischemia, exclude other diagnoses, recognize the rare appearances of cerebral ischemia, distinguish the different aspects of infarct and detect some rare diseases at the origin of the ischemic event.

Acute Disease↗
PubMed2003

[Imaging of non-traumatic intracerebral hematoma].

Intracerebral hematoma is mainly due to the spontaneous rupture of small vessels damaged by chronic hypertension or amyloid angiopathy. In some cases, intracerebral hemorrhage may be associated with a vascular malformation, a tumor, venous thrombosis or hemorrhagic transformation of a cerebral infarct. 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, a diagnosis of hematoma may be obtained by CT scan or MRI but the etiologic work-up requires early MRI. According to the patient's age, the medical history and the location of the hematoma, it may be necessary to perform conventional angiography in order to exclude an intracranial vascular malformation. The aim of this review is to detail the different aspects of intracerebral hemorrhages and to discuss the main causes that can be found at brain imaging.

Cerebral Amyloid Angiopathy↗
PubMed2002

Symptomatic vasospasm after subarachnoid haemorrhage: assessment of brain damage by diffusion and perfusion-weighted MRI and single-photon emission computed tomography.

Our purpose was to assess the usefulness of diffusion- and perfusion-weighted MRI for the detection of ischaemic brain damage in patients with suspected vasospasm after subarachnoid haemorrhage (SAH). We studied 11 patients admitted with a ruptured aneurysm of the anterior circulation and suspected of intracranial vasospasm on clinical examination and transcranial Doppler sonography (TCD). All were investigated by technetium-hexamethyl-propylene amine oxime (Tc-HMPAO) single photon emission computed tomography (SPECT) and diffusion and perfusion-weighted MRI (DWI, PWI) within 2 weeks of their SAH. Trace images and TTP maps were interpreted by two examiners and compared with clinical and imaging follow-up. PWI revealed an area of slowed flow in seven patients, including four with major and three with minor hypoperfusion on SPECT. In two patients, PWI did not demonstrate any abnormality, while SPECT revealed major hypoperfusion in one and a minor deficit hypoperfusion in the other. Two patients with high signal on DWI had a permanent neurological deficit.

Adult↗
PubMed2002

[Giant arteriovenous malformation of the vein of Galen in a 50 year old man].

True malformations of the vein of Galen are usually diagnosed within the first weeks of life. They represent less than 1 p. 100 of the cerebral arteriovenous malformations. These true malformations are exceptional in adults but should be known as an endovascular treatment could be performed. The most frequent clinical presentation is a severe cardiac failure leading to death. We report a giant arteriovenous malformation of the vein of Galen in a right-handed, 50 year-old man. During childhood, he suffered from a compensated cardiac failure which remained of unknown cause. Neurological examination showed kinetic and static cerebellar syndrome and a Parinaud syndrome. A cerebral MRI scan revealed a giant vascular malformation of the vein of Galen with a normal posterior fossa. The angiography enabled the diagnosis of a true malformation of the vein of Galen in its choroidian form. Its high blood flow entails cardiac failure because of a steal phenomenon. An endovascular treatment was declined because of numerous arterial afferences and the potential risks of peroperative haemorrhage.

Cardiac Output, Low↗
PubMed2001

[Techniques for evaluating the degree of carotid artery stenosis].

Conventional angiography is considered to be gold standard for evaluating the degree of carotid artery stenosis. However, this technique carries a risk of complications. Thus, noninvasive techniques have been developed to avoid conventional angiography. Among these techniques, duplex sonography certainly constitutes the most attractive method, providing both morphological and hemodynamic data by combining different acquisition modalities. Contrast-enhanced MR angiography (MRA) is a recent development providing information on the intracranial and cervical vascularization in a short acquisition time. Previous studies have showed the reliability of this technique to detect severe carotid stenosis. Helicoidal CT is a third noninvasive method providing a reliable evaluation of carotid artery stenosis by analyzing both the axial CT images and the 3D reconstruction. However, CT angiography requires a radiation does and injection of an iodinated contrast agent. Moreover, the surrounding venous and bone structures may obscure evaluation of the arterial lumen.

Carotid Stenosis↗
PubMed2000

Recent advances in magnetic resonance angiography of carotid and vertebral arteries.

New magnetic resonance angiographic sequences using gadolinium infusion allow high-quality images of supra-aortic vessels. Raw data may be obtained in a short scan time of less than 30 s, with a large acquisition volume from the aortic arch to the circle of Willis. After computed reconstruction of the vascular tree, angiograms appear similar to those obtained with conventional catheter angiography. Parameters of the sequence must be carefully chosen, however, with trade-offs between spatial resolution, scan time, acquisition volume and contrast of image. New developments have been proposed to improve the image quality with different acquisition strategies. These recent advances will probably be useful to assess the carotid and the vertebral arteries with more accuracy. They will require high-performance gradient systems and sophisticated software that is not yet available on all machines, however.

Brain Diseases↗
PubMed2000

[Vertebral artery dissections: follow-up with magnetic resonance angiography and injection of gadolinium].

Vertebral artery dissection is a frequent cause of ischemic stroke in young adults but time course of VA dissections remains poorly documented. Angiography was considered as the gold standard for the diagnosis. Recently, non-invasive methods have been developed such as helical CT and magnetic resonance angiography. The purpose of the study was to assess the reliability of a gadolinium-enhanced fast three dimensional (3D) magnetic resonance (MR) angiographic sequence to image vertebral arteries and to assess the long-term follow-up of vertebral artery (VA) dissections. Sixteen consecutive patients with 18 angiographically documented VA dissections were followed-up by gadolinium-enhanced 3D MR angiography and cervical T1-weighted MR imaging at a median delay of 22 months. Ten patients had MR imaging scan at the acute stage as well and nine had early follow-up angiography at a median delay of 3 months. MR angiography was evaluated in a consensus manner including image quality, presence of residual stenosis, luminal irregularities and occlusion. All patients clinically improved. Ten of 11 stenotic dissections returned to normality whereas one stenotic dissection progressed to occlusion. Two pseudoaneurysms detected on the initial angiography resolved spontaneously, one appeared only on a delayed MR angiographic scan and one was detected on early MR angiograms and finally resolved on a late one. Of the seven initially occluded VAs, five reopened with a hairline residual lumen in three. Contrast MR angiography is an interesting tool to assess the late course of VA dissections. Most lesions resolved spontaneously but persisting occlusion or pseudoaneurysm may be found in long term follow-up.

Adult↗
PubMed2000

[Supra-aortic arteries angioplasty and stenting: an ultrasonographic follow up].

PURPOSE: Ultrasonographic follow up of patients with supra-aortic arteries angioplasty and stenting was performed to determine the normal characteristics and to detect restenosis or thrombosis at the repair site. MATERIAL AND METHODS: Twenty-eight patients were followed. The delay between the procedure and the ultrasonographic examination was 1 to 5 years. There were 32 procedures: 7 carotid angioplasties with stenting; 32 vertebral angioplasties (2 stentings), 2 brachiocephalic artery angioplasties (1 stenting); 1 subclavian artery angioplasty. The ultrasonographic examination included morphological and bilateral flow analysis. The usual criteria were measured. Special attention has been given to the morphological aspect of the stents. RESULTS: All of the carotid stents were patent. No restenosis appeared during the follow up. A parietal thickening was observed in one patient without significant reduction of the arterial lumen. There were one vertebral and one brachiocephalic stent thrombosis. The results of the ultrasonographic examinations correlated well with magnetic resonance imaging. CONCLUSION: The ultrasonographic follow up of supra aortic arteries angioplasty and stenting is feasible. An early examination is recommended after the vascular procedure to control the efficacy of the repair and to detect and quantify the residual lesions. This phase is compulsory for an optimal long term follow up.

Adult↗