Vanderbilt University Institute of Imaging Science, Nashville, Tennessee, USA; Radiology and Radiological Sciences, Vanderbilt University, Nashville, Tennessee, USA; Psychiatry, Vanderbilt University School of Medicine, Nashville, Tennessee, USA; Neurology, Vanderbilt School of Medicine, Nashville, Tennessee, USA; Physics and Astronomy, Vanderbilt University, Nashville, Tennessee, USA.
J Magn Reson Imaging. 2014 Feb;39(2):377-86. doi: 10.1002/jmri.24150. Epub 2013 Apr 30.
To evaluate how flow territory asymmetry and/or the distribution of blood through collateral pathways may adversely affect the brain's ability to respond to age-related changes in brain function. These patterns have been investigated in cerebrovascular disease; however, here we evaluated how flow-territory asymmetry related to memory generally in older adults.
A multi-faceted MRI protocol, including vessel-encoded arterial spin labeling capable of flow territory mapping, was applied to assess how flow territory asymmetry; memory performance (CERAD-Immediate Recall); cortical cerebral blood flow (CBF), white matter lesion (WML) count, and cortical gray matter volume were related in older healthy control volunteers (HC; n = 15; age = 64.5 ± 7 years) and age-matched mild cognitive impairment volunteers (MCI; n = 7; age = 62.7 ± 3.7 years).
An inverse relationship was found between memory performance and flow territory asymmetry in HC volunteers (P = 0.04), which reversed in MCI volunteers (P = 0.04). No relationship was found between memory performance and cortical tissue volume in either group (P > 0.05). Group-level differences for HC volunteers performing above versus below average on CERAD-I were observed for flow territory asymmetry (P < 0.02) and cortical volume (P < 0.05) only.
Findings suggest that flow territory asymmetry may correlate more sensitively with memory performance than CBF, atrophy and WML count in older adults.
评估血流分布区不对称和/或通过侧支循环分布的血液如何对大脑响应与年龄相关的大脑功能变化的能力产生不利影响。这些模式已在脑血管疾病中进行了研究；然而，在这里我们评估了与老年人记忆力相关的血流分布区不对称模式。
应用多方面的 MRI 方案，包括能够进行血流分布区映射的血管编码动脉自旋标记，评估血流分布区不对称与记忆表现（CERAD-即时回忆）之间的关系；在年龄匹配的健康对照志愿者（HC；n=15；年龄=64.5±7 岁）和轻度认知障碍志愿者（MCI；n=7；年龄=62.7±3.7 岁）中，评估记忆表现、皮质脑血流（CBF）、脑白质病变（WML）计数和皮质灰质体积之间的关系。
在 HC 志愿者中，发现记忆表现与血流分布区不对称之间存在负相关关系（P=0.04），而在 MCI 志愿者中，这种关系则相反（P=0.04）。在两组志愿者中，记忆表现与皮质组织体积之间均无相关性（P>0.05）。仅在 HC 志愿者中，CERAD-I 表现高于或低于平均水平的志愿者之间存在血流分布区不对称（P<0.02）和皮质体积（P<0.05）的组间差异。
研究结果表明，血流分布区不对称与记忆表现的相关性可能比 CBF、萎缩和 WML 计数更为敏感，这在老年人中尤为重要。
