Department of Radiology, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India.
Department of Neurology, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi, India.
Postgrad Med J. 2023 May 22;99(1170):318-325. doi: 10.1136/postgradmedj-2021-141264.
As functional changes precede structural changes in dementia, we aimed to elucidate changes on cerebral perfusion CT (PCT) for early diagnosis of dementia; and to differentiate Alzheimer's disease (AD) from vascular dementia (VaD). We also aimed to study correlation between Montreal Cognitive Assessment (MOCA) score and PCT parameters.
We conducted a prospective case-control study enrolling 25 dementia patients (15 cases of VaD, 10 cases of AD) and 25 age-matched controls. PCT was performed on a 256-slice CT scanner. Using perfusion software, colour maps were generated for cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time and time-to-peak. These colour maps were first visually inspected for any abnormalities. Subsequently, quantitative assessment of perfusion parameters was done using symmetrical freehand region of interests drawn in bilateral frontal, temporal, parietal regions, basal ganglia and hippocampi.
Strategic infarcts were present in 93.3% cases and white matter ischaemic changes in 100% cases of VaD. A global reduction in CBF and CBV was also observed in cases of VaD; whereas these parameters were significantly lower mainly in temporoparietal regions and hippocampi of patients with AD. There was significant positive correlation between MOCA score and various perfusion parameters in both forms of dementia.
PCT is a reliable imaging modality for early diagnosis of dementia and in differentiating VaD from AD. As perfusion parameters show positive correlation with MOCA score, they could be used as a surrogate marker of cognitive status in the follow-up of patients with dementia.
由于痴呆症的功能性改变先于结构性改变，我们旨在通过脑灌注 CT（PCT）阐明其改变，以早期诊断痴呆症；并区分阿尔茨海默病（AD）和血管性痴呆（VaD）。我们还旨在研究蒙特利尔认知评估（MOCA）评分与 PCT 参数之间的相关性。
我们进行了一项前瞻性病例对照研究，纳入了 25 例痴呆症患者（15 例 VaD，10 例 AD）和 25 名年龄匹配的对照者。使用 256 层 CT 扫描仪进行 PCT。使用灌注软件生成脑血流量（CBF）、脑血容量（CBV）、平均通过时间和达峰时间的彩色图。首先对这些彩色图进行视觉检查，以观察是否存在任何异常。随后，使用对称自由手感兴趣区在双侧额叶、颞叶、顶叶、基底节和海马中对灌注参数进行定量评估。
93.3%的 VaD 病例存在战略性梗死，100%的 VaD 病例存在白质缺血性改变。VaD 患者也观察到 CBF 和 CBV 整体减少；而 AD 患者的这些参数主要在颞顶叶和海马中显著降低。两种类型的痴呆症中，MOCA 评分与各种灌注参数之间均存在显著正相关。
PCT 是一种可靠的影像学方法，可用于早期诊断痴呆症，并区分 VaD 和 AD。由于灌注参数与 MOCA 评分呈正相关，因此它们可作为痴呆症患者随访中认知状态的替代标志物。
