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Biomedical subjects

C Marsault

Publications and source records attributed to C Marsault.

At least 91 records · Page 5Linked to original sources

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↗

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↗

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↗

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↗

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↗

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↗

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↗

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↗

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↗

Imaging in the exploration of lumbosacral plexus avulsion. Two cases.

In all cases of post-traumatic sensorimotor deficit in the lower limbs unexplained by another pathology, it is not unreasonable to suspect a nerve root avulsion. Whenever available, MRI seems to be the choice examination as it is not invasive and provides a three-dimensional exploration. On the basis of two new cases and a review of the literature, the authors discuss the value of various imaging methods in this pathology.

Adult↗

MRI anatomy of the acoustic-facial bundle in vivo.

In this study performed on 5 healthy volunteers the authors used oblique axial, coronal and sagittal MRI sections suitable to be anatomical configuration of the acoustic-facial bundle and were able to individualize the nerves forming this bundle throughout their course, with the sole exception of the intermediate nerve (VII2). They also analysed the relations of these nerves between themselves and with the other elements of the cerebellopontine angle. In addition, a proton-density sequence (SE, 6,000/30 ms) made it possible to differentiate in vivo between the grey matter and the white matter sufficiently to individualize the principal nuclei and tracts of the brain stem, and in particular the main vestibulo-cochlear central pathways.

Adult↗

Gadolinium-DTPA enhanced MR imaging in tuberous sclerosis.

Ten patients with clinical tuberous sclerosis were examined with CT and MR imaging, before and after IV contrast in order to determine the role of Gd-DTPA. Gd-DTPA enhancement occurred in eleven subependymal nodules which did not enhance on CT after IV contrast. As illustrated by previous CT and pathologic observations and related to the histologic similarity of the subependymal nodules and giant-cell astrocytomas, these hyperintense nodules could represent active lesions with the potential to evolve. Four giant-cell astrocytomas were detected both with CT and Gd-DTPA-enhanced MRI; tumor conspicuity and size assessment were improved by postcontrast MRI in two cases. No cortical tuber or heterotopic cluster enhanced; T2-weighted sequences therefore remain necessary for their detection. If pre and post-Gd-DTPA T1- and T2-weighted imaging is negative, CT is clearly the most sensitive modality in the detection of the small calcified subependymal nodules.

Adolescent↗

[The new imaging technics: theoretical principles, limitations and some ideas on costs].

The new imaging techniques modify the diagnostic, or even sometimes therapeutic, decision lines. Their efficiency is much greater than that of the old techniques, while pretium doloris and side-effects are considerably reduced. Such advances are not without a major disadvantage: the ever increasing cost of imaging explorations. Radiological guidance (with conventional radiology, ultrasounds and computerized tomography) facilitates percutaneous procedures for diagnostic (biopsy) or therapeutic purposes (emptying of abscesses, chemonucleolysis of herniated lumbar disc, etc.).

Angiography↗

Magnetic resonance imaging in the exploration of dissection of the internal carotid artery.

Five patients with recent spontaneous or post-traumatic dissection of the internal carotid artery (ICA) were explored by magnetic resonance imaging (MRI), using T1-weighted axial sections in all cases. In four patients examined during the subacute phase (after 7 days) the diagnosis of ICA dissection was strongly suspected on the association of a very high intensity signal produced by the parietal haematoma with a contiguous signal void area corresponding to the lumen of the ICA. A control MRI examination performed in two patients 2 months after the onset of dissection showed that it had regressed and that the carotid arteries were patent, which was confirmed by angiography. In the fifth patient MRI provided evidence for the evolution of a post-traumatic dissection towards thrombosis. The MRI image of carotid dissection at the subacute phase seems to be characteristic. MRI is also useful to follow up dissections under treatment and to postpone angiography. The latter, however, remains necessary to investigate for associated arterial dysplasia and to evaluate the sequelae of dissection.

Adult↗

MRI evaluation of tuberous sclerosis.

The authors present four cases of tuberous sclerosis examined with MRI. The patho-anatomic aspects are reviewed and analysed with respect to MRI data. MRI appears superior to the CT particularly for imaging of cortical tubers, cystic lesions, and heterotopic clusters; these last two features were never described with MRI before. Here is also presented the second progressive case of giant intracranial aneurysm associated with tuberous sclerosis.

Adult↗