Magnetic resonance imaging of the brain

Magnetic resonance imaging (MRI) of the brain has become essential to a neurologic work-up. In Canadian centres where access to MRI is limited, use of this technique is usually restricted to assessment of disorders for which it is likely to provide unique information after computed tomography (CT); examples include abnormalities of the temporal lobes and posterior fossa, some diseases that show subtle or no abnormalities on CT (many inflammatory and demyelinating disorders) and cases in which detailed anatomic assessment is necessary (vascular malformation, congenital anomalies and many tumours). Although MRI of the brain has become quite standardized, recent developments such as improved gradient-echo imaging, new coil designs, magnetic resonance angiography and the use of contrast agents in MRI have resulted in improved speed and utility.