Dash Sanket, Agarwal Yatish, Jain Swarna, Sharma Anuradha, Chaudhry Neera
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. 2022 Jan 19. doi: 10.1136/postmj/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.
由于痴呆症的功能变化先于结构变化，我们旨在阐明脑灌注CT（PCT）的变化以早期诊断痴呆症，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25例痴呆患者（15例VaD，10例AD）和25例年龄匹配的对照。在256层CT扫描仪上进行PCT检查。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谱。首先对这些彩色图谱进行视觉检查以发现任何异常。随后，使用在双侧额叶、颞叶、顶叶区域、基底神经节和海马体中绘制的对称徒手感兴趣区域对灌注参数进行定量评估。
93.3%的VaD病例存在策略性梗死，100%的病例存在白质缺血性改变。在VaD病例中还观察到CBF和CBV整体降低；而在AD患者中，这些参数主要在颞顶叶区域和海马体中显著降低。在两种形式的痴呆症中，MOCA评分与各种灌注参数之间均存在显著正相关。
PCT是早期诊断痴呆症以及区分VaD和AD的可靠成像方式。由于灌注参数与MOCA评分呈正相关，它们可作为痴呆症患者随访中认知状态的替代指标。
