MR volumetric analysis of the human basal ganglia: Normative data

Rationale and Objectives . The authors undertook this study to identify a precise, semiautomated, reproducible magnetic resonance (MR) imaging technique for measuring the basal ganglia, to establish normative volumetric data, and to verify the presence of previously reported asymmetries. Materials and Methods . Twenty-eight healthy adults underwent cranial MR examination. The volumes of the various components of the basal ganglia were measured by means of a combination of thresholding and manual tracing techniques performed with specialized software. The validity of these measurements was assessed by fashioning, imaging, and measuring a practical basal ganglia phantom. Measurement accuracy was also established by means of inter- and intrarater reliability indexes. Normalized volumes were statistically analyzed with analysis of variance and paired t tests. Results . The absolute values of the various components of the basal ganglia varied widely even though the volumes were normalized to differences in intracranial volume. The right caudate nucleus volume was significantly ( P Conclusion . The authors have defined a precise, reproducible technique for measuring various components of the basal ganglia and have established normative data. The basal ganglia, similar to other brain structures, exhibit hemispheric lateralization.