目的：应用弥散张量成像技术(diffusion tensor imaging，DTI)比较中老年患者术前与接受全凭静脉麻醉术后海马旁回以及后扣带回白质纤维束的完整性。方法：对20例接受全凭静脉麻醉的老年患者进行术前简明精神状态量表(mini-mental state examination，MMSE)评分，并且进行术前1天及术后3天的功能磁共振扫描。分为术前组与术后组。术前组与术后组均为相同的患者。采用FSL软件对获取的磁共振图像数据进行处理，分别计算双侧海马旁回(hippocampal gyrus，PH)，双侧后扣带回(posterior cingulate cortex，PCC)的各向异性分数(fractional anisotropy，FA)和表观弥散系数(apparent diffusion coefficient，ADC)，利用SPSS软件进行统计学分析。结果：术后组双侧PH，双侧PCC的FA值较术前有所降低，ADC值较术前有所升高，差异有统计学意义(P<0.05)。结论：全凭静脉麻醉术后老年患者的海马体部白质纤维束的完整性较术前有所损害。
Diffusion tensor imaging in evaluation of the fiber integrity of the hippocampus region in middle-aged patients undergoing general anesthesia
Objective: To compare the integrity of the white matter fibers in the hippocampus of elderly patients undergoing total intravenous anesthesia by diffusion-tensor imaging. Methods: Twenty patients received total intravenous anesthesia in elderly patients with preoperative mini-mental state examination (MMSE) score, and in preoperative 1 day and postoperative 3 days, functional magnetic resonance scan was obtained, and divided into a preoperative group and a postoperative group. The two groups enrolled the same patients. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) of bilateral hippocampal gyrus (PH) and bilateral posterior cingulate cortex (PCC) were calculated. SPSS software was used for statistical analysis. Results: The FA values of bilateral PH and bilateral PCC of the postoperative group were lower than those of preoperative group. The ADC value was higher than that before operation, the difference was statistically significant (P<0.05). Conclusion: The integrity of the white matter fibers in the hippocampus of the elderly patients after total intravenous anesthesia is more impaired than before.