Nuclear magnetic resonance scanning provides the potential for measurement of new properties of tissue which may permit better pathologic differentiation. NMR will be less affected by bone, and so neurologic studies in which bone artifacts are a problem in CT may be facilitated. Direct sagittal and coronal imaging are possible. As far as we know, the biologic hazards are expected to be minimal but cannot be definitely ruled out at this time. At present, the relaxation times that are most frequently measured are such that clinically acceptable spatial resolution (2 to 3mm) requires scan times on the order of two minutes or more. Whether chemical cross-sections that are acceptable to clinical demands can be obtained remains to be demonstrated.