Schuff N, Amend D, Ezekiel F, Steinman S K, Tanabe J, Norman D, Jagust W, Kramer J H, Mastrianni J A, Fein G, Weiner M W
Magnetic Resonance Unit, Department of Veterans Affairs Medical Center, San Francisco, CA 94121, USA.
Neurology. 1997 Dec;49(6):1513-21. doi: 10.1212/wnl.49.6.1513.
Hippocampal atrophy detected by MRI is a prominent feature of early Alzheimer's disease (AD), but it is likely that MRI underestimates the degree of hippocampal neuron loss, because reactive gliosis attenuates atrophy. We tested the hypothesis that hippocampal N-acetyl aspartate (NAA: a neuronal marker) and volume used together provide greater discrimination between AD and normal elderly than does either measure alone. We used proton MR spectroscopic imaging (1H MRSI) and tissue segmented and volumetric MR images to measure atrophy-corrected hippocampal NAA and volumes in 12 AD patients (mild to moderate severity) and 17 control subjects of comparable age. In AD, atrophy-corrected NAA from the hippocampal region was reduced by 15.5% on the right and 16.2% on the left (both p < 0.003), and hippocampal volumes were smaller by 20.1% (p < 0.003) on the right and 21.8% (p < 0.001) on the left when compared with control subjects. The NAA reductions and volume losses made independent contributions to the discrimination of AD patients from control subjects. When used separately, neither hippocampal NAA nor volume achieved to classify correctly AD patients better than 80%. When used together, however, the two measures correctly classified 90% of AD patients and 94% of control subjects. In conclusion, hippocampal NAA measured by 1H MRSI combined with quantitative measurements of hippocampal atrophy by MRI may improve diagnosis of AD.
通过磁共振成像（MRI）检测到的海马萎缩是早期阿尔茨海默病（AD）的一个显著特征，但MRI可能低估了海马神经元丢失的程度，因为反应性胶质增生会减轻萎缩。我们检验了这样一个假设：海马N-乙酰天门冬氨酸（NAA：一种神经元标志物）和体积联合使用，比单独使用任何一种测量方法，在区分AD患者和正常老年人方面具有更大的辨别力。我们使用质子磁共振波谱成像（1H MRSI）以及组织分割和容积磁共振图像，来测量12例AD患者（轻度至中度严重程度）和17名年龄相仿的对照者经萎缩校正后的海马NAA和体积。在AD患者中，与对照者相比，经萎缩校正后的右侧海马区NAA降低了15.5%，左侧降低了16.2%（均为p < 0.003），右侧海马体积减小了20.1%（p < 0.003），左侧减小了21.8%（p < 0.001）。NAA降低和体积减小对区分AD患者和对照者有独立贡献。单独使用时，海马NAA和体积对AD患者的正确分类率均未超过80%。然而，联合使用这两种测量方法时，正确分类了90%的AD患者和94%的对照者。总之，通过1H MRSI测量的海马NAA与MRI对海马萎缩的定量测量相结合，可能会改善AD的诊断。
