Detecting perfusion deficit in Alzheimer's disease and mild cognitive impairment patients by resting‐state fMRI

Abstract

Background: Vascular factors contributing to cerebral hypoperfusion are implicated in the risk of developing Alzheimer's disease (AD). Purpose: To investigate the time-shift mapping created time-shift value of the brain by resting-state functional magnetic resonance imaging (rs-fMRI), and to determine the differences in time-shift value among AD, mild cognitive impairment (MCI), and normal control (NC) groups to better understand the disease. Study Type: Prospective. Subjects: Twenty-four AD, 24 MCI, and 24 age-matched NC participants. Field Strength/Sequence: T 2 *-weighted single-shot echo-planar imaging sequence was performed at 3T. In addition, a T 1 -weighted fast spoiled gradient-echo sequence was acquired for coregistration. Assessment: The brain time-shift value was determined from rs-fMRI-based blood oxygenation level-dependent (BOLD) signal in the three groups by time-shift mapping. The perfusion patterns were also investigated in the NC group. Statistical Tests: One-way analysis of variance and chi-squared tests were used to compare demographic information. The normalized time-shift maps were analyzed in a second-level test using SPM8. All analyses were evaluated with a significance level of P < 0.05 after false discovery rate (FDR) correction. Results: The time-shift maps obtained from rs-fMRI are consistent with the cerebral blood supply atlas. Compared with NC, both MCI and AD groups had less early perfusion arrival areas among the whole brain. In the delayed time-shift value for the AD group, the areas were located in the bilateral precuneus, the sensory-motor cortex in the left hemisphere, and the bilateral calcarine sulcus, which were different from the MCI group (both P < 0.05, FDR corrected). Data Conclusion: The time-shift mapping method could detect perfusion deficits in AD and MCI noninvasively. The perfusion deficits detected by rs-fMRI may provide new insight for understanding the mechanism of neurodegeneration. Level of Evidence: 2 Technical Efficacy: Stage 3

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

“…Our results provided strong evidence that the rsfMRI signals with frequencies [0.01-0.15] Hertz had higher associations between the predicted CBF and actual CBF at global lobar, individual lobe, and individual ROI compared to the signals of frequencies [0.01-0.10] Hertz and [0.01-0.20] Hertz, respectively. Perfusion estimations from rsfMRI were broadly in line with recent reports that rsfMRI signals may carry perfusion properties (Lv et al, 2013;Tong and Frederick, 2014;Yan et al, 2018). It has also been shown that the rsfMRI signals with [0.01-0.15] Hertz to a larger extent resembled perfusion measurement with dynamic susceptibility contrast compared to the signals with [0.01-0.10] Hertz (Tong et al, 2017).…”

Low Frequency Systemic Hemodynamic “Noise” in Resting State BOLD fMRI: Characteristics, Causes, Implications, Mitigation Strategies, and Applications

“…Christen et al (2014) were able to quantify delayed blood flow in moyamoya disease using a cross-correlation technique. In addition, Yan et al (2018) have successfully detected perfusion deficits (from BOLD delay) in patients with Alzheimer’s disease and mild cognitive impairment.…”

Anxiety and depression severity in neuropsychiatric SLE are associated with perfusion and functional connectivity changes of the frontolimbic neural circuit: a resting-state f(unctional) MRI study

“…These measures of time shift in the phase of low-frequency BOLD oscillations are presumed to reflect haemodynamic transfer lag or lead times and, at least, in part serve as indirect indices of regional brain perfusion. 17 18 Indices of haemodynamic lag have been validated in cases of severe acute or chronic brain ischaemia due to large vessel occlusion 14 14 16 59 60 or milder widespread haemodynamic deficits in patients with Alzheimer’s disease 61 and have been shown to represent hypoperfused tissue. On the contrary, the significance of haemodynamic lead has not been explored systematically.…”