轻度阿尔茨海默病海马各区磁共振T2信号的研究

摘要

Objective To provide the evidence for early diagnosis and treatment of Alzheimer s dis-ease(AD)by studying the MRI-T2 signals in left and right hippocampal head and tail of AD patients .Methods Twenty mild AD patients served as a mild AD group and 20 elderly subjects served as a control group and underwent FSE-T2 sequencing . The MRI-T2 signal intensity was measured at the margin of manual-outlined hippocampal subfields .The relation between MRI-T2 signal intensity and MMSE score in hippocampal subfields was analyzed .The MRI-T2 signals in hippocampal head and tail were calculated according to the ROC curve and used as a threshold val -ue for the early diagnosis of mild AD .Results The MRI-T2 signal intensity in bilateral hippocampal head was significantly higher in mild AD group than in control group (P<0 .05) .The MMSE score was negatively related with the hippocampal MRI-T2 signal intensity .The best threshold value of MRI-T2 signal intensity in the left and right hippocampal head was 563 .0 with a sensitivity of 87 .0% and a specificity of 94 .0% ,and 562 .2 with a sensitivity of 89 .0% and a specificity of 93 .0% .Conclusion Abnormal MRI-T2 signal intensity exists in bilateral hippocampal head and can be used as an auxiiliary marker in early diagnosis of AD .%目的 探讨轻度阿尔茨海默病(AD) 患者左右侧海马头体尾各部磁共振T2信号强度的变化,为AD的临床早期诊断及早期治疗提供影像学帮助.方法 选择轻度AD患者(轻度AD组)20例和老年健康体检者(对照组)20例.所有受试者均行快速自旋回波T2序列,并在工作站手工勾绘海马各部感兴趣区,测量其T2信号强度.并分析各部磁共振T2信号强度与简易智能状态检查量表(MMSE)评分的相关性.应用ROC曲线计算海马磁共振T2信号作为轻度AD临床诊断指标的阈值,并评价其价值.结果 轻度AD组双侧海马头部磁共振T2信号强度较对照组明显增高,差异有统计学意义(P<0.05).MMSE评分与轻度AD双侧海马头部呈负相关.左侧海马头部磁共振T2信号强度最佳诊断阈值为563.0,敏感性为87.0%,特异性为94.0%;右侧海马头部磁共振T2信号强度最佳诊断阈值为562.2,敏感性为89.0%,特异性为93.0%.结论 轻度AD患者双侧海马头部磁共振T2信号强度存在异常,并可作为AD早期诊断有价值的辅助指标之一.