脑白质病影像学诊断（Imaging diagnosis of brain white matter）.docVIP

脑白质病影像学诊断（Imaging diagnosis of brain white matter） I. Introduction There are many diseases involved in the central nervous system of white matter, while the white matter lesions are divided into primary and secondary two categories. Secondary to the central nervous system infection, poisoning, degeneration and trauma and other diseases of the white matter, secondary brain white matter; primary white matter of the disease, referred to as primary white matter disease, referred to as white matter. The white matter of the brain is divided into 2 categories according to whether the myelin sheath is mature at the time of the disease: 1. congenital and hereditary white matter disease This kind of leukoencephalopathy is usually called leukodystrophy or hereditary leukodystrophy, myelin formation, maintenance and decomposition is a cause of abnormal cerebral white matter myelination disorder. This kind of disease usually includes: adrenoleukodystrophy, metachromatic leukodystrophy, spherical cell leukodystrophy, spongiform encephalopathy, Alexander disease, cortical axon dysplasia. 2. acquired white matter of the brain Acquired brain white matter disease mainly refers to the normal development of mature myelin has been destroyed, namely: demyelination disease. It mainly includes: multiple sclerosis, progressive multifocal leukoencephalopathy, acute disseminated encephalomyelitis, subacute sclerosing panencephalitis, central pontine myelinolysis, corpus callosum degeneration, subcortical arteriosclerotic encephalopathy and concentric sclerosis etc.. Two. The structure, development and imaging diagnosis of normal white matter (1) the structure of the white matter of the brain The white matter of the brain is mainly composed of nerve fibers, while nerve fibers are divided into two types: myelinated and unmyelinated. The myelinated nerve fibers are surrounded by a medullary structure called myelin. In the electron microscope, the myelin sheath is formed by a thin, flat membrane