QUANTIFICATION OF CEREBELLAR STRUCTURES WITH MRI

Methodological issues have limited neuroimaging studies of cerebellar structures. In this article we describe a method that addresses some o f these limitations and phantom studies that examine the validity of t he image manipulations. We compared volumes derived from 3D Spoiled Gr adient Recalled Acquisition MR images sliced with respect to three dif ferent alignment methods: one based on cerebellar landmarks, another o n cerebral landmarks and a third on the plane of acquisition. Examinat ion of coefficients of variation, coefficients of error and convergent validity suggests that although regional cerebellar volumes based on cerebellar landmarks provide the best estimates of the true volumes, o bserved differences between volume measurements from alignments based on cerebellar or cerebral landmarks were generally not significant and were inconsequential. In this case, the measure was improved with ali gnment along local, relevant cerebellar landmarks. A set of phantom ex periments showed that realignment, reslicing and interpolation in 3-di mensional image processing exerted, at most, trivial distortion on the estimates of actual object volumes. (C) 1997 Elsevier Science Ireland Ltd.