MR VOLUME ESTIMATION OF SUBCORTICAL BRAIN-LESIONS AND VENTRICULAR CEREBROSPINAL-FLUID - A SIMPLE AND ACCURATE STEREOLOGIC METHOD

PURPOSE: To describe an MR imaging quantification method for estimatio n of total volumes of both white and gray matter subcortical lesions a nd ventricular cerebrospinal fluid (CSF) in the living human brain, an d to determine the method's reliability. METHODS: In 12 subjects, tota l subcortical lesion and ventricular CSF volumes were estimated using systematic sampling. Systematic sampling was performed on equidistant MR sections using a counting grid with systematically ordered intersec tion points. The grid was randomly positioned on each consecutive MR s ection, Each grid intersection point hitting the structure of interest represents a fixed known volume dependent on grid intersection point distance and the sum of the section thickness and section gap. RESULTS : Total volume estimation of subcortical lesion and ventricular CSF ta kes 15 and 5 minutes per subject, respectively. Coefficients of error of the individual volume estimates ranged from .01 to .13 and are negl igible to the coefficients of the group mean (range, .70 to .89). For subcortical lesion volume, the random intraobserver error yielded .04 and for ventricular CSF .02; the random interobserver error amounted t o .11 and .04, respectively; and the systematic interobserver error wa s .15 and .04, respectively. CONCLUSION: The method described here for subcortical lesion and ventricular CSF volume estimation is accurate, reliable, valid, and fast.