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P Demaerel

Publications and source records attributed to P Demaerel.

138 records · Page 8Linked to original sources
PubMedDate not supplied

Axial vs sagittal T2-weighted brain MR images in the evaluation of multiple sclerosis.

Axial and sagittal proton density and T2-weighted MR images (TR 2,500-3,000 ms, TE 15-22 and 85-90 ms) were performed in 50 patients with multiple sclerosis (MS) on a 1.5 T superconductive system. The number of plaques on the axial and sagittal images in the periventricular white matter, the corpus callosum, the brain stem, the cerebellum, and the basal ganglia were counted separately by two independent observers. A total of 858 lesions (mean 17.40 +/- 21.57) were seen on the axial series and 1,196 (mean 24.32 +/- 26.22) on the sagittal scans. More lesions were visualized on sagittal images in the periventricular region (mean 18.79 +/- 21.69 versus 13.34 +/- 16.45; p less than 0.001) and the corpus callosum (mean 3.00 +/- 2.72 versus 0.57 +/- 1.19; p less than 0.001). In the brain stem more lesions were visualized on the axial images (mean 1.55 +/- 2.55 versus 0.87 +/- 1.20; p less than 0.05). In the cerebellum and basal ganglia, scans in the two planes were equivalent (p greater than 0.5). In three patients lesions were seen on the sagittal series, while the axial scans were normal. Sagittal T2-weighted images appear to demonstrate significantly more MS plaques than transverse images, especially in the periventricular region and the corpus callosum. This is explained by partial volume averaging, by the orientation of some cerebral structures (e.g., corpus callosum) with regard to the section plane, and by the longer diameter of the lesions in the axial plane.

Brain Diseases↗
PubMedDate not supplied

Intermediate short-term outcomes after brain computed tomography and magnetic resonance imaging in neurology outpatients.

OBJECTIVE: The purpose of this study was to assess and compare the impact of magnetic resonance imaging (MIR) and computed tomography (CT) on diagnostic and therapeutic decision making, taking into account the real cost of both techniques at the authors' institution. METHOD: Brain CT and routine and rapid MRI were compared, and case files were prepared with either the CT or the MRI findings. These files were separately presented to a neurologist, and different questions were asked about further management. The real cost of CT and MRI was calculated. A questionnaire was sent to the patients 3 months after imaging. RESULTS: More lesions were detected on MRI than on CT Routine and rapid AIRI were comparable. The analysis of the CT case files revealed an additional request for MRl in 33% of the patients. An analysis of the MRI case files revealed that 20% more technical examinations were requested after MRI than after CT In the majority of the patients (90%), neuroimaging had no impact on therapy except by means of reassurance of the physician. The scan was considered useful for therapeutic planning by excluding the presence of a space-occupying lesion. The real cost of the MP! strategy was 9% higher than that of the CT strategy. CONCLUSION: In this patient population, neuroimaging was normal in the majority of the patients. Undergoing an imaging examination was of benefit to the patients and improved their sense of well-being mainly by the reassurance they experienced, as reported by 91% of the patients. At the authors' institution, the real cost of MMI in this patient population was only slightly higher than the real cost of CT The statistical analysis favors the use of MRI as a 1st imaging examination.

Adolescent↗
PubMedDate not supplied

Cortical visual impairment following perinatal hypoxia: clinicoradiologic correlation using magnetic resonance imaging.

PURPOSE: To evaluate the value of magnetic resonance imaging (MRI) in the visual prognosis of cortical visual impairment following perinatal hypoxia. METHODS: MRI findings of 19 babies with the diagnosis of a perinatal hypoxic-ischemic insult and cortical visual impairment (CVI) were reviewed. Two groups of patients based on gestational age were compared. Babies with a gestational age > or = 34 weeks were included in group 1(n = 8). Infants < 34 weeks' gestation were included in group 2(n = 11). All 19 children underwent MRI. RESULTS: Normal MRI always correlated with better visual outcome, regardless of the gestational age at which the insult occurred. Among infants born at or later than 34 weeks' gestation, a favorable visual recovery occurred in two with normal MRI findings. The presence of infarcts or periventricular leukomalacia indicated that full visual recovery would not occur. Among infants born before 34 weeks' gestation, the MRI findings were normal in two who had a favorable visual outcome. A normal visual cortex and the absence of periventricular leukomalacia were helpful in prognosticating the visual outcome. A general delay in the myelination-particularly in the myelination of the optic radiation-was a common finding and until now has not been described in children with CVI routinely. CONCLUSION: MRI's ability to follow the process of myelination may be of predictive value. MRI, therefore, should be obtained in a child with CVI following perinatal hypoxia.

Asphyxia Neonatorum↗
PubMedDate not supplied

Gyriform calcifications in tuberous sclerosis simulating the appearance of Sturge-Weber disease.

Two cases of tuberous sclerosis are presented. Extensive superficial occipital calcifications were found as classically described in Sturge-Weber syndrome. Other radiologic signs of tuberous sclerosis, such as subependymal calcifications in both patients and surgically proved giant cell astrocytoma in one patient, were present. At pathologic examination, the calcifications appeared to be located in extensive cortical tubers.

Brain Diseases↗
PubMedDate not supplied

Prominent dural enhancement adjacent to nonmeningiomatous malignant lesions on contrast-enhanced MR images.

Prominent dural enhancement was noted in 10 (16%) of 61 superficial malignant intracranial tumors studied with contrast-enhanced MR imaging during a 2-year period. Included were six glioblastomas, three parenchymal metastases, and one case of dural metastasis. Seven patients had surgery. In four, there was extensive leptomeningeal invasion in the center of the lesion. In two of these lesions there was firm attachment of the center of the tumor to the dura, but without dural invasion despite extensive external carotid artery supply to the tumor in one case. In two cases the overlying dura was normal, and there was no leptomeningeal tumoral invasion. In the case of dural metastasis, huge nodular lesions were present along the inner aspect of the dura. In none of the cases did prominent dural enhancement adjacent to the tumor correspond with tumoral invasion or extension to the dura. Prominent dural enhancement on contrast-enhanced MR images appears to be much less frequent in malignant tumor than in meningioma, where it is seen in up to 60% of the cases. We believe this finding is more likely to represent reactive changes of the dura than tumoral invasion.

Brain Neoplasms↗
PubMedDate not supplied

Intracranial meningiomas: correlation between MR imaging and histology in fifty patients.

The magnetic resonance (MR) findings in 50 surgically verified intracranial meningiomas were reviewed. An attempt was made to correlate their signal intensity on spin echo (SE) T1-weighted, proton density [N(H)], and T2-weighted images with the different histologic subtypes. The T1-weighted images were nonspecific in differentiating the subtypes of meningiomas. On proton density and T2-weighted images, more information was available, but there remained large group (46%) of meningiomas that were not classifiable. The average signal intensity scores on T1-weighted, proton density, and T2-weighted images in the different histologic subtypes were correlated with each other using the Student t test. Only one significant correlation (psammomatous-anaplastic) and three almost significant correlations (syncytial-transitional or psammomatous and transitional-psammomatous) were found. Different histologic subtypes may have a different MR appearance, but this does not suffice to reach a histologic diagnosis by MR imaging.

Adult↗
PubMedDate not supplied

Orbital cavernous hemangioma: findings on sequential Gd-enhanced MRI.

OBJECTIVE: To describe the contrast enhancement pattern of orbital cavernous hemangioma on sequential Gd-enhanced MRI. MATERIALS AND METHODS: Six patients with an orbital mass lesion were examined with T1- and T2-weighted spin echo MRI. After intravenous administration of Gd-chelate at a dose of 0.1 mmol/kg, T1-weighted spin echo sequences were performed immediately after, after 15 to 30 min, and up to 1 h after the injection. In two patients a fat saturation prepulse was given before the Gd-enhanced study. RESULTS: In all patients the lesions were isointense to muscle on the T1-weighted sequence and hyperintense to muscle on the T2-weighted sequences. After gadolinium, all lesions showed initial central patchy enhancement. Between 20 and 60 min after the injection the lesions showed total and homogeneous filling up. CONCLUSIONS: Progressive and total homogeneous filling up of an orbital mass of Gd-enhanced MRI is a pathognomonic sign of cavernous hemangioma.

Artifacts↗