Andreasen N C, Rajarethinam R, Cizadlo T, Arndt S, Swayze V W, Flashman L A, O'Leary D S, Ehrhardt J C, Yuh W T
Mental Health Clinical Research Center, University of Iowa Hospitals and Clinics, College of Medicine, Iowa City 52242-1057, USA.
J Comput Assist Tomogr. 1996 Jan-Feb;20(1):98-106. doi: 10.1097/00004728-199601000-00018.
MRI offers many opportunities for noninvasive in vivo measurement of structure-function relationships in the human brain. Although automated methods are now available for whole-brain measurements, an efficient and valid automatic method for volume estimation of subregions such as the frontal or temporal lobes is still needed.
We adapted the Talairach atlas to the study of brain subregions. We supplemented the atlas with additional boxes to include the cerebellum. We assigned all the boxes to 1 of 12 regions of interest (ROIs) (frontal, parietal, temporal, and occipital lobes, cerebellum, and subcortical regions on right and left sides of the brain). Using T1-weighted MR scans collected with an SPGR sequence (slice thickness = 1.5 mm), we manually traced these ROIs and produced volume estimates. We then transformed the scans into Talairach space and compared the volumes produced by the two methods ("traced" versus "automatic"). The traced measurements were considered to be the "gold standard" against which the automatic measurements were compared.
The automatic method was found to produce measurements that were nearly identical to the traced method. We compared absolute measurements of volume produced by the two methods, as well as the sensitivity and specificity of the automatic method. We also compared the measurements of cerebral blood flow obtained through [15O]H2O PET studies in a sample of nine subjects. Absolute measurements of volume produced by the two methods were very similar, and the sensitivity and specificity of the automatic method were found to be high for all regions. The flow values were also found to be very similar by both methods.
The automatic atlas-based method for measuring the volume of brain subregions produces results that are similar to manual techniques. The method is rapid, efficient, unbiased, and not subject to the problems of rater drift or potentially poor interrater reliability that plague manual methods. Consequently, this method may be very useful for the study of structure-function relationships in the human brain.
磁共振成像（MRI）为无创体内测量人脑结构 - 功能关系提供了诸多机会。尽管现在已有用于全脑测量的自动化方法，但仍需要一种高效且有效的自动方法来估计额叶或颞叶等脑亚区的体积。
我们将Talairach图谱应用于脑亚区研究。我们在图谱中添加了额外的方框以纳入小脑。我们将所有方框分配到12个感兴趣区域（ROI）中的1个（额叶、顶叶、颞叶、枕叶、小脑以及脑左右两侧的皮质下区域）。使用通过扰相梯度回波（SPGR）序列采集的T1加权磁共振扫描（层厚 = 1.5毫米），我们手动勾勒出这些ROI并得出体积估计值。然后我们将扫描图像转换到Talairach空间，并比较两种方法（“勾勒”与“自动”）得出的体积。勾勒测量值被视为与自动测量值进行比较的“金标准”。
发现自动方法得出的测量结果与勾勒方法几乎相同。我们比较了两种方法得出的体积绝对测量值，以及自动方法的敏感性和特异性。我们还比较了在9名受试者样本中通过[15O]H2O正电子发射断层扫描（PET）研究获得的脑血流量测量值。两种方法得出的体积绝对测量值非常相似，并且发现自动方法对所有区域的敏感性和特异性都很高。两种方法得出的血流量值也非常相似。
基于图谱的自动测量脑亚区体积的方法产生的结果与手动技术相似。该方法快速、高效且无偏差，不受困扰手动方法的评分者漂移问题或潜在的评分者间可靠性差的问题影响。因此，该方法可能对研究人脑结构 - 功能关系非常有用。
