Brannen J H, Badie B, Moritz C H, Quigley M, Meyerand M E, Haughton V M
Department of Radiology, University of Wisconsin, Madison, USA.
AJNR Am J Neuroradiol. 2001 Oct;22(9):1711-8.
Functional MR (fMR) imaging of word generation has been used to map Broca's area in some patients selected for craniotomy. The purpose of this study was to measure the reliability, precision, and accuracy of word-generation tasks to identify Broca's area.
The Brodmann areas activated during performance of word-generation tasks were tabulated in 34 consecutive patients referred for fMR imaging mapping of language areas. In patients performing two iterations of the letter word-generation tasks, test-retest reliability was quantified by using the concurrence ratio (CR), or the number of voxels activated by each iteration in proportion to the average number of voxels activated from both iterations of the task. Among patients who also underwent category or antonym word generation or both, the similarity of the activation from each task was assessed with the CR. In patients who underwent electrocortical stimulation (ECS) mapping of speech function during craniotomy while awake, the sites with speech function were compared with the locations of activation found during fMR imaging of word generation.
In 31 of 34 patients, activation was identified in the inferior frontal gyri or middle frontal gyri or both in Brodmann areas 9, 44, 45, or 46, unilaterally or bilaterally, with one or more of the tasks. Activation was noted in the same gyri when the patient performed a second iteration of the letter word-generation task or second task. The CR for pixel precision in a single section averaged 49%. In patients who underwent craniotomy while awake, speech areas located with ECS coincided with areas of the brain activated during a word-generation task.
fMR imaging with word-generation tasks produces technically satisfactory maps of Broca's area, which localize the area accurately and reliably.
对部分因开颅手术而入选的患者，已采用词生成功能磁共振成像（fMR）来定位布罗卡区。本研究旨在测量词生成任务识别布罗卡区的可靠性、精确性和准确性。
将34例连续接受语言区fMR成像定位的患者在执行词生成任务时激活的布罗德曼区制成表格。在执行两次字母词生成任务的患者中，通过使用符合率（CR）对重测可靠性进行量化，即每次迭代激活的体素数量与该任务两次迭代激活的体素平均数量的比例。在还进行了类别或反义词词生成或两者皆有的患者中，用符合率评估各任务激活的相似性。在清醒开颅手术期间接受言语功能皮层电刺激（ECS）定位的患者中，将言语功能部位与词生成fMR成像时发现的激活位置进行比较。
在34例患者中的31例中，一项或多项任务使布罗德曼区9、44、45或46的额下回或额中回单侧或双侧激活。当患者执行字母词生成任务的第二次迭代或第二项任务时，在相同脑回中观察到激活。单个层面像素精确性的符合率平均为49%。在清醒开颅手术的患者中，ECS定位的言语区与词生成任务期间激活的脑区相符。
词生成任务的fMR成像可产生技术上令人满意的布罗卡区图谱，能准确且可靠地定位该区域。
