Jack C R, Gehring D G, Sharbrough F W, Felmlee J P, Forbes G, Hench V S, Zinsmeister A R
Department of Diagnostic Radiology, Mayo Clinic, Rochester, MN 55905.
J Comput Assist Tomogr. 1988 Jan-Feb;12(1):21-9. doi: 10.1097/00004728-198801000-00003.
The effect of several magnetic resonance (MR) variables on the accuracy of volume measurements in phantom objects was investigated by use of an off-line automatic border-outlining and internal area pixel-counting computer program, and an optimal set of imaging variables was identified. Measurements were made of the temporal lobe volumes of a gross fixed brain specimen from MR image data. The range in accuracy was from -2 to +7%, and the standard deviation of the difference in right minus left lobe volume measurements obtained from the MR images and those obtained by use of Archimedes' principle was 1 cm3. This volumetric technique was applied to 25 normal persons, most of whom were right-handed. The median ratio of right to left temporal lobe volume was 1.16 (range 0.99-1.23). The nondominant temporal lobe was significantly larger than the dominant. The mean difference (95% confidence interval) between right and left volumes was 7 cm3 (6-9 cm3). This confidence interval was similar to that obtained when the variability within a subject (estimated from the gross fixed brain specimen) was taken into account. Unilateral temporal lobe atrophy, particularly in patients with temporal lobe epilepsy, should be interpreted from MR images with this range of discrepancy in normal left-right size in mind.
通过使用离线自动边界勾勒和内部区域像素计数计算机程序，研究了几个磁共振（MR）变量对模型物体体积测量准确性的影响，并确定了一组最佳成像变量。根据MR图像数据对一个大体固定脑标本的颞叶体积进行了测量。准确性范围为-2%至+7%，从MR图像获得的右叶减去左叶体积测量值与使用阿基米德原理获得的值之间差异的标准差为1cm³。这种体积测量技术应用于25名正常人，其中大多数是右利手。右颞叶与左颞叶体积的中位数比值为1.16（范围0.99 - 1.23）。非优势颞叶明显大于优势颞叶。左右体积的平均差异（95%置信区间）为7cm³（6 - 9cm³）。该置信区间与考虑受试者内部变异性（根据大体固定脑标本估计）时获得的结果相似。在解读MR图像时，应考虑到正常左右大小存在这种差异范围，尤其是在颞叶癫痫患者中出现的单侧颞叶萎缩情况。
