Neuroimaging for the Clinician

Modern neuroimaging has revolutionized the practice of neurology by allowing visualization and monitoring of evolving pathophysiologic processes. High-resolution magnetic resonance imaging (MRI) can now resolve structural abnormalities on a near-cellular level. Advances in functional imaging can assess the in vivo metabolic, vascular, and functional states of neuronal and glial populations in real time. Given the high density of data obtained from neuroimaging studies, it is essential for the clinician to take an active role in understanding the nature and significance of imaging abnormalities. This chapter reviews computed tomography and MRI techniques (including angiography and advanced sequences), specialized protocols for investigating specific diagnoses, risks associated with imaging, disease-specific imaging findings with general strategies for interpretation, and incidental findings and artifacts. Figures include computed tomography, T1- and T2-weighted signal intensity, diffusion-weighted magnetic resonance imaging, magnetic resonance spectroscopy, imaging in epilepsy and dementia, extra-axial versus intra-axial lesions, typical lesions of multiple sclerosis, spinal imaging, spinal pathology, vascular pathology, intracranial hemorrhage, and common imaging artifacts. Tables list Hounsfield units, patterns of enhancement from imaging, advanced techniques in imaging, magnetic resonance imaging sequences, and the evolution of cerebral infarction and intraparenchymal hemorrhage on magnetic resonance imaging. This review contains 12 figures, 6 tables, and 213 references.