Evaluation of incidental findings on MRI of the central nervous system: part 1.

During the course of routine neuroradiologic imaging evaluation, various abnormalities are occasionally identified that may be considered "incidental findings." The significance of these is not always clear, and additional evaluation may be necessary. This article presents a series of magnetic resonance (MR) images to illustrate a number of "incidental findings," describes possible significance, and where additional evaluation or follow-up may be required.