• Scotti G and Gerevini S (2001). Diagnosis and differential diagnosis of acute transverse myelopathy. The role of neuroradiological investigations and review of the literature. Neurol Sci 22 Suppl 2:S69-73. Summary: Acute transverse myelopathy (ATM) is a clinical definition of an acute neurologic condition that reflects impairment of spinal cord function. The term "myelopathy" has a different meaning from "myelitis", even if the words are often confused. Both terms indicate spinal cord involvement by some pathological event; but while myelopathy does not imply any etiological factor, myelitis refers to inflammatory diseases of the spinal cord. Acute spinal pathology can be associated with intra-axial or extra-axial lesions; extra-axial spinal pathology, however, has more often a chronic and progressive presentation. In this paper, we discuss primarily intra-axial lesions with attention on the role of neuroradiological investigations in diagnosis and differential diagnosis. Magnetic resonance imaging is the modality of choice for diagnosis; it shows signal abnormalities, usually T2 hyperintensity, focal or extensive, gadolinium enhancement and sometimes cord swelling. Despite its high sensitivity, about 40% of acute transverse myelopathies remain undemonstrated. Concerning etiology (multiple sclerosis (MS), vasculitis, infection, autoimmune disorders) no clearly different and specific patterns have been found; however small multiple enhancing lesions are more suggestive of MS (or lupus) while extensive, multilevel abnormalities reflect vasculitis as in antiphospholipid antibody syndrome. Department of Neuroradiology, Scientific Institute H.S. Raffaele, Milan, Italy.