Giubergia Alice, Ferrazzi Giulio, Castellaro Marco, Mascheretti Sara, Lampis Valentina, Montano Florian, Bertoldo Alessandra, Peruzzo Denis
Scientific Institute IRCCS Eugenio Medea, Neuroimaging Unit, Bosisio Parini, Italy.
University of Padova, Department of Information Engineering, Padova, Italy.
Imaging Neurosci (Camb). 2025 Jul 28;3. doi: 10.1162/IMAG.a.94. eCollection 2025.
Functional magnetic resonance imaging (fMRI) studies in cognitive and clinical neuroscience rely on blood oxygenation level-dependent (BOLD) contrast, measured with single-shot gradient-echo-planar imaging. However, conventional schemes encompass the acquisition of single-echo fMRI, which samples a single echo at a single-echo time (TE), facing limitations in disentangling neural signals from artifacts. Multi-echo (ME) fMRI captures images at multiple echo times within a single repetition time (TR) period and enables the separation of BOLD and non-BOLD signal components. Previous studies have highlighted the benefits of ME-fMRI but often relied on comparisons with suboptimal single-echo data derived from ME acquisitions, limiting the validity of these evaluations. This study performs a more rigorous comparison between three datasets: the data acquired with an optimized single-echo (OSE) fMRI sequence at the highest possible temporal resolution, those acquired with an ME-fMRI sequence, and, as previously reported in the literature, the echo-2 time-series extracted from the ME-fMRI data itself. ME-fMRI echo-2 comparison confirmed previous findings, which advantage the ME approach. However, the acquisition of multi-echo fMRI did not clearly outperform an optimized single-echo scheme. While OSE-fMRI exhibits benefits in terms of higher statistical power, ME-fMRI demonstrates superior performance at the single-subject level in terms of reliability (p < 0.05). Additional investigation and optimization could clarify the conditions under which one sequence may be preferred over the other.
认知神经科学和临床神经科学中的功能磁共振成像（fMRI）研究依赖于通过单次激发梯度回波平面成像测量的血氧水平依赖（BOLD）对比。然而，传统方案包括单回波fMRI的采集，即在单个回波时间（TE）对单个回波进行采样，在从伪影中分离神经信号方面存在局限性。多回波（ME）fMRI在单个重复时间（TR）周期内的多个回波时间采集图像，并能够分离BOLD和非BOLD信号成分。先前的研究强调了ME-fMRI的优势，但通常依赖于与从ME采集中获得的次优单回波数据进行比较，这限制了这些评估的有效性。本研究在三个数据集之间进行了更严格的比较：以尽可能高的时间分辨率使用优化单回波（OSE）fMRI序列采集的数据、使用ME-fMRI序列采集的数据，以及如文献中先前报道的，从ME-fMRI数据本身提取的回波2时间序列。ME-fMRI与回波2的比较证实了先前的发现，即ME方法具有优势。然而，多回波fMRI的采集并没有明显优于优化的单回波方案。虽然OSE-fMRI在更高的统计效力方面表现出优势，但ME-fMRI在单受试者水平上在可靠性方面表现更优（p < 0.05）。进一步的研究和优化可以阐明在哪种情况下一种序列可能比另一种更受青睐。
