Cerebral Perfusion Insufficiency and Relationships with Cognitive Deficits in Alzheimer’s Disease: A Multiparametric Neuroimaging Study

Abstract

Micro- or macro-circulatory insufficiency has a negative impact in patients with Alzheimer’s disease (AD). This study used arterial spin-labeled magnetic resonance imaging (ASL-MRI) and ethylcysteinate dimer single-photon emission computed tomography (ECD-SPECT) in 50 patients with AD and 30 age-matched controls to investigate how hypoperfusion patterns were associated with gray matter atrophy and clinical data. All participants completed 3DT1-MRI, ECD-SPECT and ASL-MRI examinations. Medial temporal cortex (MTC) volumes were correlated with regional signals showing significantly lower relative cerebral blood flow (rCBF) in ASL-MRI or perfusion index (PI) in ECD-SPECT. Neurobehavioral scores served as the outcome measures. Regions with lower PI showed spatial similarities with atrophy in the medial, anterior and superior temporal lobes, posterior cingulate cortex and angular gyrus, while regions showing lower rCBF were localized to the distal branches of posterior cerebral artery territories (posterior parietal and inferior temporal lobe) and watershed areas (angular gyrus, precuneus, posterior cingulate gyrus and middle frontal cortex). rCBF values in watershed areas correlated with MTC volumes and language composite scores. Precuneus and angular gyrus hypoperfusion were associated with the corresponding cortical atrophy. Macro- or micro-vasculature perfusion integrities and cortical atrophy determined the overall perfusion imaging topography and contributed differently to the clinical outcomes.

Estimating regional cerebral blood flow using resting-state functional MRI via machine learning

“…In our findings, the estimated relative CBF at superior parietal lobule was significantly lower in more impaired MCI patients based on MMSE (< 28) compared to the cognitively normal group. This result was in agreement with prior studies that have reported decreased relative CBF in MCI or Alzheimer's pathology Huang et al, 2018). Interestingly, MCI patients with higher MMSE (³ 28) had higher estimated perfusion, albeit not statistically significant.…”

“…This approach will be useful especially for studies that have large sample size (Habes et al, 2016), where reacquiring missing imaging modalities from the same subject is not practical. CBF estimation was better at the posterior regions, where many previous studies (Alsop et al, 2008;Dolui et al, 2017;Huang et al, 2018) and our results showed altered CBF in MCI or Alzheimer's pathology, suggesting the potential use of proposed method in those populations.…”

Implementing the proclamation of stroke and potentially preventable dementias

“…All failures of major organs lead to different degrees of cognitive impairment. Heart failure constitutes the most prevalent . Kidney failure represents another common example, the cognitive status often fluctuating with the dates of dialysis.…”

“…Heart failure constitutes the most prevalent. [15][16][17][18][19] Kidney failure represents another common example, the cognitive status often fluctuating with the dates of dialysis.…”

Correlação de imagens metabólicas (PET 18F-FDG) com imagens de fluxo sanguíneo (PET 11C-PIB) em idosos com queixa de memória

“…Segundo Huang et al (2018) Uma das limitações do estudo é a determinação do intervalo de tempo para as imagens de PET 11 C-pPIB (0 a 10 minutos), que foi inicialmente considerada para representar o padrão de distribuição do fluxo sanguíneo cerebral desse traçador em particular. Estudos recentes (Ponto, et al, 2019, Bilgel et al, 2019; mostraram que a melhor correlação de 11 C-pPIB e FSCr foi observada nas primeiras imagens (em tempos mais curtos de aquisição), segundo Peretti et al, (2019), a melhor correlação de 11 C-pPIB e FSCr é no intervalo de tempo preferido de 20 a 130 segundos de aquisição.…”