Amplitude of Low Frequency Fluctuations (ALFF) and fractional Amplitude of Low Frequency Fluctuations (f/ALFF) are neuroimaging methods used to measure spontaneous fluctuations in BOLD-fMRI signal intensity for a given region in the resting brain.

Jan 1, 2017 · We calculated the fractional amplitude of low frequency fluctuations (fALFF) in a group of 64 participants scanned 3 months post-stroke. Twenty showed depression symptoms when assessed with the Patient Health Questionnaire (PHQ-9).

Jul 3, 2021 · 本文介绍了任务态fMRI与静息态fMRI的区别，任务态侧重于执行任务时的模型驱动分析，如GLM+HRF，而静息态则更注重数据驱动的特征，如功能连接、ReHo和ALFF。 ReHo衡量局部一致性，ALFF探测低频波动强度，有助于理解大脑活动模式和自发活动的特性。 | 图源. 任务态和静息态是大脑的两种状态，前者主要是指大脑在执行记忆、识别以及运动等具体任务时的 …

Nov 1, 2020 · Background: Fractional amplitude of low-frequency fluctuation (fALFF) alterations in young depressed patients with suicide attempts after cognitive behavioral therapy (CBT) and antidepressant medication cotherapy were evaluated.

Jul 18, 2017 · Measuring the amplitude of low frequency fluctuations allows the detection of spontaneous neural activity across the whole brain. It provides complementary information about frequency-specific local neural activity.

Jul 15, 2008 · The current study proposed a fractional ALFF (fALFF) approach, i.e., the ratio of power spectrum of low-frequency (0.01-0.08 Hz) to that of the entire frequency range and this approach was tested in two groups of resting-state fMRI data.

Jan 11, 2017 · The resting-state functional magnetic resonance imaging data were obtained on a Philips 3.0 Tesla scanner and analysed using the fractional amplitude of low frequency fluctuation (fALFF) method. Correlations of fALFF values with cognitive dysfunction were further analysed.

The fALFF value reflects the intensity of regional neural spontaneous activity; a decrease in fALFF value suggests reduced spontaneous neuronal activity, while an increase indicates potential compensatory brain functional activity (Azouvi et al., 2003).

Nov 15, 2022 · Our aim was to analyse the correlation between the fractional amplitude of low-frequency fluctuation (fALFF) and FER ability in FSZ patients.

We aim to characterize fALFF and seed-based FC changes among different types of strokes and healthy control group, and show how to use fALFF values and functional connectivity maps to specify a target map on the cortical surface for the rTMS.

We calculated the fractional amplitude of low frequency fluctuations (fALFF) in a group of 64 participants scanned 3 months post-stroke. Twenty showed depression symptoms when assessed with the Patient Health Questionnaire (PHQ-9).

Amplitude of Low Frequency Fluctuations (ALFF) and fractional ALFF (fALFF) - Measure the power of slow fluctuations in brain activity. Regional Homogeneity (ReHo) - Measure the similarity of activity patterns across neighboring voxels.

Sep 7, 2022 · As a resting-state functional magnetic resonance imaging (RS-fMRI) signal, fractional amplitude of low-frequency fluctuation (fALFF), which covers the low-frequency power spectrum (0.01–0.08 Hz), reflects the intensity of local spontaneous activity in brain areas by quantifying the low-frequency oscillations (LFOs) [10, 11].fALFF is minimally ...

Compared to ALFF, fractional ALFF (fALFF) reduces physiological noise interference from intracranial venous sinuses and cerebrospinal fluid, significantly improving the sensitivity and specificity of detecting spontaneous brain activity (Zou et al., 2008). fALFF analysis has been widely applied in studies on stroke (Egorova et al., 2017, Wang et...

The fALFF was developed after the original ALFF index to detect intrinsic spontaneous brain activity with higher sensitivity and specificity. It can provide a more specific measure of low oscillatory phenomena (Zou et al., 2008, 2010).

Nov 16, 2023 · Fractional ALFF (fALFF) assessment is an advanced technique based on blood oxygen level-dependent (BOLD) fMRI signal intensity of a resting brain. fALFF examinations reduce nonspecific physiological artefacts in rs-fMRI and are thus highly sensitive and specific for detecting spontaneous neuronal activity .

Nov 1, 2020 · Fractional amplitude of low-frequency fluctuation (fALFF) alterations in young depressed patients with suicide attempts after cognitive behavioral therapy (CBT) and antidepressant medication cotherapy were evaluated. Seventy-eight subjects (age: 18–28) were recruited from April 2017 to March 2019.

Dec 3, 2024 · Surface-based ALFF/fALFF in POAG decreased in visual processing regions and increased in brain regions related to cognitive control, working memory, and attention. These changes were linked to neurotransmitter distributions important for emotional stability and mental health, potentially informing treatment approaches for POAG patients.

Jan 1, 2024 · We conducted this resting-state functional magnetic resonance imaging (rsfMRI) study to characterize changes in regional homogeneity (ReHo) or fractional amplitude of low-frequency fluctuations (fALFF) in young adult patients with major depressive disorder (MDD), with or without non-suicidal self-injury (NSSI).

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