Search PubMed⌕ Search

Biomedical subjects

C Marsault

Publications and source records attributed to C Marsault.

At least 73 records · Page 4Linked to original sources
PubMed1996

Long-term MR follow-up of cerebral lesions in neuro-Behçet's disease.

To study the long-term evolution of cerebral lesions in neuro-Behçet's disease, MRI was carried out on 12 patients, with follow-up from 1.5 to 6 years (mean 3.5 years). On the first MRI, 66 lesions in all were found; each patient had 1-10 lesions (mean 5.5). There were 30 (46%) lesions in the brain stem, 18 (27%) in the basal ganglia region and 18 (27%) in the periventricular white matter. Of these 22 (33%) were small, 31 (47%) medium-size and 13 (20%) large lesions. On the last MRI, 60 lesions were found: each patient had 1-10 lesions (mean 5). At this time 31 lesions (52%) were in the brain stem, 13 (22%) in the basal ganglia region and 16 (26%) in the periventricular white matter. There were 41 (68%) small, 13 (22%) medium-size and 6 (10%) large lesions. About 40% of the lesions disappeared, 35% reduced in size and 25% remained unchanged. No lesion had enlarged. Of the 60 final lesions 20 (34%) were not observed on the first study. Small new lesions were found in 5 of 12 patients (42%), and were asymptomatic. Medium-size or large new lesions were found in 2 patients (17%) who had stopped steroid treatment and had a neurological relapse. Enlargement of the ventricular system or worsening of initial cerebral atrophy was observed in 9 of 12 patients. Appearance of small lesions and worsening of cerebral atrophy on long-term follow-up suggest the possibility of subclinical progression of cerebral vasculitis and should be considered in the prognosis of neuro-Behçet's disease.

Adolescent↗
PubMed1996

[Iridium 192 brachytherapy of supra-tentorial high grade glioma recurring in irradiated areas: technique and preliminary results of the Pitié-Salpêtrière hospital group].

UNLABELLED: Our aim was to analyse feasibility and preliminary results obtained with iridium 192 re-irradiation of recurrent high grade gliomas. MATERIAL AND METHODS: a technique for implanting rigid plastic tubes afterloaded with iridium 192 wires was developed that utilised a stereotactic Leksell frame. Nineteen glioblastomas and one anaplastic glioma (12 males and 8 females: age: 20-69 years, median: 50) were implanted between January 1993 and December 1994. Previous treatments included surgery (18/20). 55-60 Gy external beam radiotherapy (20/20), and chemotherapy (16/20); interval between initial treatment and retreatment with iridium 192 was 6 to 39 months (median: 10). Maximum diameter of the tumour at the moment of implantation was 2.1-10.1 cm (median: 6.4 cm) and tumour volume 2.122 cm3 (median: 22 cm3). All tumours were supra-tentorial (right hemisphere: 9; left hemisphere: 11). Karnofsky index was 60-100 (median: 80). Implantation was carried out under local anaesthesia; tumour contours were visualised using either a CT-scan (16/20) or a MRI (4/20). Dosimetry was carried out using two orthogonal films and CT-scan images. Total dose on the reference isodose was 40-60 Gy (60 Gy: 9; 50 Gy: 7; 40 Gy: 4); dose-rate was 0.24-0.73 Gy/h (median: 0.38). RESULTS: probability of overall survival is 90% at 6 months, 55% at one year, and 26% at two years. Median survival is 56 weeks. Eleven patients died from local failure, and three from leptomeningeal metastasis. Six patients are alive, 15-30 months after the implantation. Two were reoperated for brain necrosis. Three patients showed evidence of bacterial meningitis, and three others of skin necrosis. CONCLUSION: according to this preliminary analysis, results obtained after reirradiation of high grade gliomas with iridium 192 are encouraging. More patients and longer follow-up are needed to draw definitive conclusions.

Adult↗
PubMed1996

[Magnetic resonance imaging of temporal lobe epilepsy].

MR has gained more and more importance in the evaluation of patients with temporal lobe epilepsy (TLE). Until recently, hippocampal sclerosis (which is the most frequent cause of temporal lobe epilepsy, accounting for 50-70% of the cases) could not be identified reliably. Using optimized magnetic resonance imaging techniques, hippocampal sclerosis can now be evidenced in a large proportion of patients with TLE. Tumors (10-15%), developmental abnormalities (5-7%), vascular malformations (mostly cavernous angiomas, 1-5%), and traumatic scars (5-10%) represent the other structural lesions associated with TLE. Studies of large series of patients with intractable epilepsy or with varying severity have shown that in only 8.5% and 20%, respectively, a specific imaging abnormality was not found. Specific MR sequences increase the diagnostic value of MR (coronal images perpendicular to the axis of the hippocampal formations, three-dimensional T1 weighted images, inversion recovery images, volumetry or more specific processes such as T1 and T2 relaxometry or spectroscopy). MR also helps guide placement of intra-cerebral and subdural electrodes in surgically relevant cases. All these results have given greater importance to MR in the definition of the epileptic syndrome of TLE and should probably be integrated in the criteria of international classifications.

Adult↗
PubMed1996

[Subarachnoid rupture of supratentorial dermoid cyst: CT and MRI aspects].

We report a case of ruptured subarachnoid dermoid cyst which was explored with both CT and MRI. This rare condition results from the accumulation of a large amount of fat with a characteristic aspect at-imaging. Rupture causes fat dissemination in the subarachnoid space. In most cases, CT or MRI can provide sure diagnosis of the tumor and of rupture.

Adult↗
PubMed1995

Registration in neurosurgery and neuroradiotherapy applications.

Because of the high level of accuracy needed in neurosurgery, many computer-assisted surgery (CAS) and augmented reality techniques have been developed in this field. A common issue with all of these techniques is registration between preoperative three-dimensional images (computed tomography and magnetic resonance imaging) and the patient in the operating room. We present, in the first part of this paper, a survey of the latest CAS technologies, using fully automatic registration without fiducial landmarks. All of the registration algorithms described are based on minimization of a cost function. We then describe our approach. Our cost function is simply the mean square error (MSE), minimized by the iterative closest point algorithm (ICP). Because the weak point of the ICP algorithm is the closest point computational cost, we precalculate it by a "closest point map," inspired from classical distance map. We finally perturb the found solution to eliminate local minima close to the global minimum. This paper summarizes the various methods presented. We study the shape of the different cost functions and show that there is no need for a complex cost function. MSE has sufficiently good convergence properties to reach a position very close to the global minimum. We also demonstrate the influence of a final perturbation of the found solution to improve registration. Finally, we test the registration on different regions of the patient's head.

Algorithms↗
PubMed1995

A randomized study of bolus fluorouracil plus folinic acid versus 21-day fluorouracil infusion alone or in association with cyclophosphamide and mitomycin C in advanced colorectal carcinoma.

From May 1988 to June 1992, 129 eligible patients suffering from measurable advanced colorectal cancer were enrolled in a randomized study comparing bolus fluorouracil plus leucovorin (FU-FA); continuous fluorouracil infusion (FU-cont); FUcont plus cyclophosphamide and mitomycin C (FUMIC). FU-FA consisted of weekly fluorouracil (FUra) bolus (600 mg/m2) 1 hour after the initiation of a 2-hour infusion of 500 mg/m2 of leucovorin, for 6 weeks every 8 weeks. FUcont patients were planned to receive 400 mg/m2/day FUra infusion, for 21 days every 28 days. In FUMIC patients, FUcont was associated with weekly cyclophosphamide bolus (300 mg/m2) and monthly mitomycin C bolus (10 mg/m2). Quality of life was evaluated using six linear analogue scales, completed by the patient. Accrual in the FUMIC arm was stopped after the 25th patient because of toxicity. The response rates were 22 of 48 (45.8%) with FUcont and 13 of 52 (25%) with FU-FA (P = .048). Progression-free survival (median: 8 v 4.4 months; P = .0026) and overall survival (median: 12.9 v 9.6 months; P = .028) were significantly greater for the FUcont arm compared with the FU-FA arm. Toxicity was observed in 62% of the FUcont patients (grade 3-4: 10%), mainly hand-foot syndrome, diarrhea, mucositis, and mainly gastrointestinal in 69% of the FU-FA patients (grade 3-4: 11.6%). Linear analogue scales exploring quality of life, available for the first 6 months, gave similar scores in FU-FA and FUcont patients. We conclude that this FUcont schedule, achieving high FUra dose-intensity, offers significant advantages, in terms of response and survival, over weekly FUra plus leucovorin.

Adenocarcinoma↗
PubMed1995

Memory disorders in probable Alzheimer's disease: the role of hippocampal atrophy as shown with MRI.

Magnetic resonance based volumetric measures of hippocampal formation, amygdala (A), caudate nucleus (CN), normalised for total intracranial volume (TIV), were analysed in relation to measures of cognitive deterioration and specific features of memory functions in 18 patients with probable Alzheimer's disease. Neuropsychological examination included the mini mental state examination (MMSE), the Mattis dementia rating scale (DRS), tests of executive functions, assessment of language abilities and praxis, the Wechsler memory scale (WMS), the California verbal learning test (CVLT) and the Grober and Buschke test. The volume of the hippocampal formation (HF/TIV) was correlated with specific memory variables: memory quotient and paired associates of the WMS; intrusions and discriminability at recognition for the Grober and Buschke test. By contrast, except for intrusions, no correlations were found between memory variables and the volume of amygdala (A/TIV). No correlations were found between the volume of caudate nuclei (CN/TIV) and any neuropsychological score. The volume of the hippocampal formation was therefore selectively related to quantitative and qualitative aspects of memory performance in patients with probable Alzheimer's disease.

Aged↗
PubMed1995

Developmental abnormalities of the medial temporal lobe in patients with temporal lobe epilepsy.

PURPOSE: To evaluate MR temporal lobe malformations and their frequency in patients with temporal lobe epilepsy. METHODS: Two hundred twenty-two consecutive adult patients with temporal lobe epilepsy of varying severity were investigated with 1.0-T or 1.5-T MR units using three-dimensional T1-weighted acquisition protocol. RESULTS: Sixteen patients (7.2%) presented with malformations of the temporal lobe. Four patterns of malformations were encountered: (a) heterotopia (n = 1), lining the temporal horn of the lateral ventricle; (b) focal neocortical dysgenesis (n = 6), which consisted of cortical thickening, poor gray/white matter demarcation, abnormal gyration (n = 5), or limited schizencephaly (n = 1); (c) hippocampal malformations (n = 5), which presented as abnormal hippocampal formation associated with a cyst (n = 2), isolated malformation of the subiculum (n = 1), or bilateral hippocampal malformation (n = 2) consisting of an abnormal shape and a misplaced fimbria; (d) complex malformations of the temporal lobe, combining categories a, b, and c (n = 4). The age at onset, severity of the disease, and occurrence of generalized tonicoclonic seizures were not significantly different between patients with malformations and the entire population of patients with temporal lobe epilepsy. CONCLUSION: MR analysis of temporal lobe malformations allowed a precise determination of the extent of the malformations and the presence or absence of associated hippocampal disease, all of which are of great help in the preoperative evaluation of patients with intractable epilepsy.

Adolescent↗
PubMed1994

Complete spontaneous thrombosis of a giant intracranial aneurysm.

In a 23-year-old woman CT demonstrated a patent giant intracranial aneurysm. MRI, CT and angiography one month later demonstrated complete spontaneous thrombosis of the aneurysm. The diagnosis was confirmed surgically and pathologically. This case demonstrates that a normal angiogram can be associated with a thrombosed giant aneurysm, and that this diagnosis should be considered in cases of angiographically-occult cerebral vascular malformations.

Adult↗
PubMed1994

Randomised double blind trial of the safety and efficacy of two gadolinium complexes (Gd-DTPA and Gd-DOTA).

The main difference between macrocyclic Gd-DOTA and linear Gd-DTPA complexes is the greater stability of the former which theoretically might reduce biological interactions in man. To evaluate the clinical relevance of this property, 300 unselected neurological patients were included in a randomised double-blind comparison involving five European centres, focused mainly on the tolerance of these two contrast media. Clinical tolerance was assessed immediately after the procedure and 24 h later. Adverse events were found with a similar frequency in the two groups (17.3% for Gd-DOTA and 19.3% for Gd-DTPA). Minor neurological symptoms were the most frequent (48.6%) headache being the most common (29.2% of adverse events). No difference in efficacy was found.

Adult↗
PubMed1994

Risk factors and clinical relevance of nosocomial maxillary sinusitis in the critically ill.

The incidence of infectious maxillary sinusitis (IMS) and its clinical relevance was prospectively studied in 162 consecutive critically ill patients who were mechanically ventilated for a period longer than 7 d. All had a paranasal computed tomographic (CT) scan within 48 h of admission and were divided into three groups according to the radiologic aspect of their maxillary sinuses: Group 1 = normal maxillary sinuses (n = 40), Group 2 = maxillary mucosal thickening (n = 26), Group 3 = radiologic maxillary sinusitis (RMS) defined as the presence of an air fluid level and/or opacification of maxillary sinuses (n = 96). Group 1 patients were randomized between nasal and oral endotracheal intubation with a gastric intubation performed via the same route and had a second paranasal CT scan 7 d later. Endotracheal and gastric tubes were left in their original position in Group 2 patients and a second paranasal CT scan was performed 7 d later. All patients of Group 3 underwent a transnasal puncture for bacteriologic analysis of maxillary sinus content. Forty-five spontaneously breathing patients served as a control group. In all patients with RMS, the occurrence of bronchopneumonia (BPN) was prospectively assessed for 7 d following the initial CT scan. Upon inclusion, only 25% of the patients had normal maxillary sinuses whereas all patients in the control group had normal paranasal CT scans. After 7 d, 46% of Group 2 patients had evidence of RMS. Risk factors for RMS were nasal placement and duration of endotracheal and gastric intubation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

MR of isolated leptomeningeal glioma.

We report the MR study of a case of high-grade glioma that mimics leptomeningeal carcinomatosis. Superficial gliomas should thus be included in the differential diagnosis of isolated meningeal enhancement.

Adult↗
PubMed1994

MRI in cerebral venous thrombosis.

Fifty-three patients with cerebral venous thrombosis (CVT) were explored by MRI. Three types of signal abnormalities were observed in thrombosed sinuses: 1) isosignal on T1-weighted sequence and low-intensity signal on T2-weighted sequence (early stage); 2) high-intensity signal on T1-and T2-weighted sequences (intermediate stage); 3) isosignal on T1-weighted sequence and high-intensity signal on T2-weighted sequence (late stage). Signal abnormalities in dural sinuses enabling CVT to be diagnosed were absent in 2 out of 53 cases. Twenty-six out of 53 patients had venous infarction. These lesions were haemorrhagic in 20 cases. MRI made it possible to follow the course of CVT in 15 cases, showing partial or complete recanalization of the occluded sinuses in 14 cases. Our study confirmed that MRI is an excellent non-invasive method to explore CVT. It diagnoses the venous thrombosis, studies parenchymal lesions and follows the course of CVT under treatment. However, MRI is less sensitive than arteriography, particularly in cases of CVT involving only the cortical veins.

Adolescent↗
PubMed1994

Amygdalohippocampal MR volume measurements in the early stages of Alzheimer disease.

PURPOSE: To evaluate the accuracy of hippocampal and amygdala volume measurements in diagnosing patients in the early stages of Alzheimer disease. METHODS: Measurements of the hippocampal formation, amygdala, amygdalohippocampal complex (the two measurements summed), caudate nucleus, and ventricles, normalized for total intracranial volume, were obtained on coronal sections (1.5 T, 400/13 [repetition time/echo time], 5 mm) of 13 patients in the mild (minimental status > or = 21) and five patients in the moderate stages of Alzheimer disease (10 < minimental status < 21), and eight age-matched control subjects. RESULTS: For patients with a minimental status score of 21 or greater, atrophy was significant for the amygdala and hippocampal formation (-36% and -25% for amygdala/total intracranial volume and hippocampal formation/total intracranial volume, respectively), but not for the caudate nucleus. No significant ventricular enlargement was found. For patients with a minimental status score less than 21, atrophy was more severe in all structures studied (amygdala/total intracranial volume, -40%; hippocampal formation/total intracranial volume, -45%; caudate nucleus/total intracranial volume, -21%), and ventricles were enlarged (63%). No overlap was found between Alzheimer disease and control values for the amygdalohippocampal volume, even in the mild stages of the disease. In Alzheimer disease patients, hippocampal formation volumes correlated with the minimental status. CONCLUSION: Hippocampal and amygdala atrophy is marked and significant in the mild stages of Alzheimer disease. Volumetric measurements of the amygdala and the amygdalohippocampal complex appear more accurate than those of the hippocampal formation alone in distinguishing patients with Alzheimer disease.

Aged↗
PubMed1994

A technique of measuring the precision of an MR-guided stereotaxic installation using anatomic specimens.

PURPOSE: To develop a method for direct measurement, using anatomic specimens, of the precision of MR-guided stereotaxic location and to describe its application to a 1.5-T MR unit with a Leksell stereotaxic frame. METHODS: Small pieces of gelfoam (1 X 1 X 1 mm), soaked in gadopentetate dimeglumine, were stereotaxically introduced into formalin-fixed human heads using a Leksell D (three experiments) or G (nine experiments) stereotaxic frame. The head and the frame were then introduced into a 1.5-T MR unit. The target coordinates (as set on the stereotaxic frame by one investigator) were then compared with the MR-determined stereotaxic coordinates (calculated independently by another investigator). The imprecisions Ex, Ey, and Ez in each direction were defined as the differences between the calculated and the chosen coordinates. RESULTS: Regarding the three targets studied with the D frame, mean imprecision Ex was 1.08 +/- 0.50 mm (mean +/- SEM), Ey 0.83 +/- 0.58 mm, and Ez 0.75 +/- 0.25 mm. For the nine targets studied with the G frame, Ex was 0.48 +/- 0.17 mm, Ey 0.69 +/- 0.14 mm, and Ez 0.82 +/- 0.13 mm. Statistical analysis of the results showed no significant difference between Ex or Ey and half the size of a pixel, indicating that, in the axial plane, stereotaxic MR precision is limited only by pixel size. A statistically significant difference was observed in the coronal plane between Ez and half the size of a pixel, but it must be stressed that Ez remained smaller than 1 mm. CONCLUSION: MR-guided stereotaxic location can be used with confidence for most diagnostic, functional, and therapeutic procedures.

Calibration↗
PubMed1993

Superior vena cava thrombosis related to catheter malposition in cancer chemotherapy given through implanted ports.

BACKGROUND: Thrombosis of the central veins is one of the most frequent complications of implanted venous access devices. Among the first cases occurring in our patients, most were associated with left-sided placement of the ports, with catheter tips lying against the external wall in the upper half of the superior vena cava. Some chest radiographs showed lateromediastinal opacities centered on the catheter tip, suggesting a vessel injury. This position allows a narrow contact between the catheter tip and the vessel wall, thus endothelial injuries might result from mechanical and chemical attack. METHODS: To assess the role of catheter position, we reviewed the routine chest radiographs of 379 patients who received chemotherapy through venous access devices and were followed up at our department between December 1985 and December 1990. Four groups (upper left, upper right, lower left, and lower right) were defined according to the level of the catheter tip (innominate veins or upper half of the vena cava versus lower half of the vena cava or auricula) and to the side of port implantation. RESULTS: Ten patients developed symptomatic venous thrombosis (superior vena cava in 9 patient, left subclavian vein in 1 patient). A strong correlation existed between catheter position and incidence of thrombosis: upper left, 8/28 (28.6%); upper right, 1/33 (3%); lower right, 1/68 (1.5%); and lower left, 0/250. Since 1988, we have insisted on replacement of malpositioned catheters, and we have observed fewer thromboses (2/191 versus 8/188). CONCLUSIONS: The current study suggests that patients with left-sided ports and catheter tips lying in the upper part of the vena cava are at high risk for severe thrombotic complications.

Antineoplastic Agents↗
PubMed1992

MRI in neurosarcoidosis.

Nine patients with neurological manifestations of sarcoidosis were explored by MRI and, in some cases, CT. The MRI examinations were performed in T1- and T2-weighted spin-echo sequences in all patients, with gadolinium injection in seven. Several non-specific lesions were demonstrated, the most frequent of them showing on T2-weighted sequences as high-intensity signals in the periventricular white matter and the semi-oval centres. Other abnormalities, such as infiltrations of the hypothalamo-pituitary region, granulomatous masses within the brain tissue and meningeal infiltrations, were observed. These findings were in agreement with those found in the literature. Gadolinium injection seems to be important in this pathology, as it demonstrates lesions that are not visible on conventional T1- and T2-weighted spin-echo sequences.

Adult↗