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P Demaerel

Publications and source records attributed to P Demaerel.

At least 55 records · Page 3Linked to original sources
PubMed1998

Cranial CT revisited: do we really need contrast enhancement?

The aim of this study was to define guidelines for intravenous contrast administration in cranial CT, as currently there are no recent guidelines based on a large series of patients. In 1900 consecutive patients (1480 adults and 420 children) pre- and post-contrast scan was analysed in order to assess the contribution of contrast enhancement to the diagnosis. The findings were grouped according to whether abnormalities were seen on the pre- and/or post-contrast scan, or whether no abnormalities were seen at all. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of a pre-contrast scan were used to determine validity. Intravenous contrast enhancement only contributes to the diagnosis if a suspicious abnormality is seen on the unenhanced scan or in the appropriate clinical setting (33.6%). In the remaining patients (65.6%) there is no diagnostic contribution, except for a small number of abnormalities (0.8%). These are often anatomical variants and have no therapeutic impact. The number of contrast-enhanced cranial CT examinations can significantly be reduced by using four general guidelines for contrast administration resulting in considerable cost savings without affecting the quality of service to the patient. These guidelines are defined by the clinical findings/presentation or by the findings on the unenhanced scan. The number of contrast-related complications will be reduced, which may have medicolegal implications. These guidelines can be applied in any radiology department.

Adolescent↗
PubMed1998

Functional MRI of the brain: localisation of eloquent cortex in focal brain lesion therapy.

The aim of this study was to assess the feasibility of functional MRI (fMRI) in a clinical environment on a large patient group, and to evaluate the pretherapeutic value of localisation of eloquent cortex. Forty patients with focal brain lesions of different origin were studied using fMRI. Functional information was obtained using motor, somatosensory, auditory and phonological stimuli depending on the localisation of the lesions. To obtain information about the spatial accuracy of fMRI, the results were compared with postoperative electrocortical stimulation. Two patients with secondary trigeminal neuralgia were scanned using a motor protocol and were implanted with an extradural plate electrode. Imaging was successful in 40 of 42 patients (including the 2 with trigeminal neuralgia). These patients were analysed for strength of activation, the relation of the lesion to activation sites and the presence of mass effect. The correlation between these data and surgical findings provided significant additional clinical information. Functional MRI can be accurately performed in patients with focal brain lesions using a dedicated approach. Functional MRI offers important clinical information as a contribution to a decrease in posttherapeutic morbidity. The accuracy of the technique can be confirmed by other modalities, including invasive cortical electrostimulation.

Adolescent↗
PubMed1998

Spontaneous spinal epidural hematoma associated with thrombolysis and anticoagulation therapy: report of three cases.

Three patients with a spontaneous spinal epidural hematoma are presented, one of which is exceptional because it could be attributed to thrombolysis with alteplase. The other two were correlated with oral anticoagulant therapy. Our second case suggests that Morbus Kahler may be an underlying pathology in spinal extradural hematoma. In the third patient neither an obvious 'locus minoris resistentiae' nor a pathological coagulation test could be held responsible for the spontaneous bleeding. All three patients underwent laminectomy and evacuation of the hematoma. Although two of our cases are examples of complete recuperation after late operative intervention, early surgery is preferable. Permanent clinical attention together with a low threshold to perform magnetic resonance imaging (MRI) leads to a quicker diagnosis of spinal epidural hematoma. We show that administration of gadolinium may facilitate correct preoperative localization of the hematoma because there may be contrast enhancement of the hematoma. Finally, the postoperative policy concerning thromboembolic prophylaxis is discussed.

Aged↗
PubMed1998

Epidermoid tumours associated with lumbar punctures performed in early neonatal life.

Three children (ages 5, 7, and 12 years) with epidermoid tumours in the spinal canal, all of whom had a lumbar puncture during the early neonatal period, are reported. A considerable delay occurred from the first symptoms until the diagnosis was made. MRI of the lumbar spine was the method of choice in the diagnostic work-up. All three cases were successfully surgically treated. The link between lumbar punctures and epidermoid tumours and the possible risk factors involved are explored. Because of the variable clinical presentation, the possibility of the existence of these tumours should be considered in the differential diagnosis.

Age Factors↗
PubMed1998

MR of cerebellar cortical dysplasia.

MR imaging findings are described in four patients with cerebellar cortical dysplasia. Typically, cerebellar disorganized folia were seen as an irregular bumpy gray-white matter interface. In addition, cystlike cortical abnormalities were observed in two patients and associated supratentorial developmental abnormalities were seen in three patients. To our knowledge, cerebellar cortical dysplasia without supratentorial abnormalities, as seen in one patient, has not been reported before. We suggest that cerebellar cortical dysplasia represents a spectrum of abnormalities ranging from mild to extensive in severity.

Adolescent↗
PubMed1997

Positron emission tomography, magnetic resonance imaging and proton NMR spectroscopy of white matter in multiple sclerosis.

OBJECTIVE: To assess characteristics of MS lesions and normal appearing white matter (NAWM) with various imaging modalities. Glucose metabolism was investigated with FDG-PET, metabolite concentration with proton NMR spectroscopy, and lesion detection with routine brain MRI. METHODS: Thirteen patients were studied in a stable phase of their disease, and two during an acute episode. Nine healthy volunteers served as controls. RESULTS: Three patients had a normal brain MRI, 12 had typical lesions. MR images were registered to the PET planes. Lesions and contra-lateral control areas were analyzed, 10/15 lesions showed relative hyper-metabolism and 2 hypo-metabolism. NAA concentration was significantly decreased in both lesions and NAWM. CONCLUSION: In stable MS, most large lesions have a relatively increased glucose utilization and decreased NAA concentration. NAWM showed a significantly decreased NAA concentration compared to healthy subjects, but no difference in glucose metabolism. Active lesions in acute MS are also hyper-metabolic. This finding opens a new window on the classification of white matter lesions based on glucose utilization.

Acute Disease↗
PubMed1997

Spinal epidural hematoma and ankylosing spondylitis.

Spinal epidural hematoma is an unusual condition requiring urgent neurosurgical intervention. Imaging plays an important role in the preoperative work-up. Although MR imaging is the examination of choice, a myelogram and CT myelogram are often performed in an emergency situation. The association with ankylosing spondylitis has been described and is considered a risk factor for developing a hematoma.

Cervical Vertebrae↗
PubMed1996

Juvenile fibrosarcoma of the temporal bone.

A case of juvenile fibrosarcoma arising from the head and neck region is described. This type of tumour should be considered as a separate entity different from the fibrosarcoma in adults because of the different clinical behaviour. The symptomatology, the radiographic features and the literature data are reviewed.

Child, Preschool↗
PubMed1996

Anaplastic (malignant) ganglioglioma arising from heterotopic grey matter nodules.

Anaplastic ganglioglioma is a rare malignant neoplasm. The short clinical course and the anaplastic histological features are characteristics of malignant ganglioglioma. Immunohistochemistry is necessary for the final diagnosis. The MRI appearances are described here for the first time in literature. Nodular grey matter heterotopias had been demonstrated and the patient developed an anaplastic ganglioglioma two years later, on the same place where the grey matter heteropias had been seen. This finding supports the hypothesis that these tumours may arise from grey matter nodules.

Adult↗
PubMed1996

Interhemispheric lipoma with variable callosal dysgenesis: relationship between embryology, morphology, and symptomatology.

Eight interhemispheric lipomas (five tubulonodular lipomas and three curvilinear lipomas) were examined by magnetic resonance imaging (MRI). The purpose was to further investigate the relationship between the morphology of the different subtypes and the clinical presentation. The imaging findings were reviewed in light of a recent theory on the development of the corpus callosum. Interhemispheric lipomas should be considered as one entity with a variable expression depending on the severity and/or the time of the insult. Curvilinear lipomas can be either small or extensive and are usually not symptomatic. Tubulonodular lipomas can be either predominantly anterior or posterior in location. The anterior subtype appears to be a more severe form of tubulonodular lipoma. The associated structural abnormalities are most likely responsible for the symptoms, rather than the lipoma itself. Magnetic resonance imaging allows a more precise timing of the insult, resulting in the development of a lipoma. The knowledge of the embryology between the 6th and the 20th week is important to explain these abnormalities. Until now it has been accepted that the corpus callosum develops in an orderly fashion. A recent theory has demonstrated that this is not necessarily true, and that fibers can cross the midline at any place irrespective of the normal development. This theory explains the sometimes amorphous appearance of the remnant of the corpus callosum if a lipoma is present.

Adolescent↗
PubMed1996

The role of cranial computed tomography in the diagnostic work-up of headache.

Approximately 18% of all patients referred for a cranial computed tomography complain of headache only. We reviewed 363 consecutive patients in order to assess the value of this examination in the diagnostic approach. Despite the vast number of normal examinations (88.4%), we advocate the routine use of a cranial computed tomography in every patient with chronic headache. The cost of the examination can significantly be reduced by performing an unenhanced scan only. An additional contrast-enhanced scan should be obtained if a suspicious lesion is seen. Brain magnetic resonance imaging is not indicated except in the preoperative workup of a lesion visualized on computed tomography.

Adolescent↗
PubMed1996

Chondrosarcoma of the skull base: CT, MR and pathological features.

We report on CT and MR image findings of a skull base chondrosarcoma. Chondroid mineralisation, a histological feature of chondrosarcoma, can be recognised on CT and is, together with the off-midline position of the tumour, the most characteristic finding. Differentiation is usually made by histological and immunocytochemical staining. Surgery, proton radiation therapy and stereotactic single high-dose irradiation have been used to treat patients with chondrosarcoma. It is worth mentioning that it was likely that the chondrosarcoma in our patient represented a malignant degeneration of an enchondroma that had been resected 30 years earlier.

Aged↗
PubMed1996

Leber congenital amaurosis--differential diagnosis, ophthalmological and neuroradiological report of 18 patients.

Between 1985 and 1995 eighteen babies, presenting to our department with absent visual contact and roving eye movements, showed a non-recordable flash electroretinogram (fERG). This was confirmed when repeated after a one-year interval. In four patients with developmental delay an underlying systemic disorder was diagnosed after a thorough pediatric neurological evaluation: Senior Loken syndrome, neuroaxonal dystrophy, ceroid lipofuscinosis and a yet unclear metabolic disorder were the revised diagnoses. The fourteen remaining patients were diagnosed as having primary idiopathic Leber Congenital Amaurosis (LCA). Three of them showed developmental delay. In all three cerebellar abnormalities were visualized on brain computed tomography (CT) and/or magnetic resonance imaging (MRI). Brain CT of the other eleven patients with age appropriate development was normal. We conclude that LCA is a diagnosis of exclusion and a cautious approach with a thorough history and pediatric neurological examination is necessary to exclude a more global pediatric neurological disorder.

Belgium↗