Abstract
Recent advances in magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA) provide many advantages in diagnostic radiology. Unruptured aneurysms and arteriovenous malformations can be diagnosed with MRI and MRA. Recently, the incidence of such cases at our hospital has increased. However, MRI and MRA are not fully reliable; both false positive and false negative results may be obtained. In this report, we present these cases and discuss some problems about brain dock. In 1994, four patients were required re-examination with MRA. Three had had false positive results on previous examination. Because MRA is not always diagnostic, we always perform cerebral angiography as well. New techniques of MRA are more sensitive ; but because MRA equipment is expensive, old techniques cannot easily be changed for new. Indeed, MRA equipment is not standardized among hospitals. We believe that criteria for the diagnosis of brain check up (brain dock) must be established. We also believe that the proper training of radiology technicians and radiologists is a necessity.
