Biomedical subjects

D Margain

Publications and source records attributed to D Margain.

5 recordsLinked to original sources

PubMed1991

Astrocytic tumours.

Astrocytic tumours are frequent, accounting for nearly 50% of all brain tumours. They are divided into three groups: benign astrocytomas, anaplastic astrocytomas and malignant glioblastomas. The usual clinical manifestations of benign astrocytic tumours are epileptic seizures, whereas those of glioblastomas are rapidly progressing neurological deficits. These lesions show fairly characteristic neuroradiological features which have been largely studied. Injections of iodine-based or paramagnetic contrast media are important since they help in tumour grading: low-grade tumours are not enhanced, while glioblastomas are almost invariably enhanced. MRI seems to be indispensable for the study of astrocytic tumours: it provides an excellent anatomical analysis of the lesion during preoperative or pretherapeutic evaluation, and it is the only available method to confirm low-grade lesions that have passed unnoticed or have merely been suspected at CT. To avoid missing these tumours, every adult presenting with recent onset epileptic seizures should be explored by MRI using T2-weighted spin-echo sequences.

Adult↗

PubMed1991

Oligodendrogliomas.

Oligodendrogliomas are tumours developed from oligodendrocytes. They may be pure or associated with astrocyte proliferation. They are usually benign, but their malignancy grade is varied. These tumours affect middle-aged adults and are characterized by their slow growth and their fairly suggestive neuroradiological features which are those of a large, calcified, poorly enhanced, peripheral frontal lesion. Computerized tomography and magnetic resonance imaging are suitable complementary methods to characterize the tumour and evaluate its extension.

Adult↗

PubMed1991

Brain metastases.

Brain metastases are frequent, accounting for 20% of all brain tumours. The most common primary tumours responsible for brain metastases are lung cancer in man and breast cancer in women. Most metastases are located at the grey matter-white matter junction, in junctional vascular territories and in the rolandic region. Although non-specific, MRI is the most sensitive neuroradiological method for the lesions, especially when accompanied by gadolinium injection. MRI must absolutely be performed before surgical treatment, as gadolinium might detect other metastatic lesions or show metastatic tumours so small that they were not visible at computerized tomography (CT).

Aged↗

PubMed1991

Primary and secondary lymphomas of the brain: an MRI study.

Three types of lymphoma of the central nervous system are known: primary non-Hodgkin's malignant lymphoma (NHML), secondary NHML and neurological lesions of Hodgkin's disease. NHML's are rare tumours, often associated with immunodeficiency and presenting predominantly as neuropsychological disorders. In this study 8 patients were explored by CT and MRI, with pathological confirmation. None of our patients had AIDS. The most typical neuroradiological image of this type of tumour is that of a large and intensely contrast-enhanced tumoral mass which is often multifocal and periventricular with infiltration of the subarachnoidal spaces and leptomeninges. Mass effect and perifocal oedema are less pronounced than expected with tumours of that size. NHML's may totally regress under corticosteroid therapy. This tumour of obscure aetiology must be recognized as it is now increasingly frequent.

Aged↗

PubMed1991

Supratentorial ependymomas. Neuroradiological study.

Ependymoma is a rare tumour developed from ependymal cells and belonging to the group of neuroglial tumours. It may be located in any part of the central nervous system, but shows a preference for the ventricular cavities. Neuroradiology is not specific. CT shows a frequently large, calcified and cystic lesion of varied density and strongly contrast-enhanced. The signal emitted at MRI is often heterogeneous. Treatment consists of surgery combined with radiotherapy. Prognosis is poor owing to the difficulty of surgical excision and to the possibility of CSF grafts.

Adult↗