Dionisio-Parra Beatriz, Wiesinger Florian, Sämann Philipp G, Czisch Michael, Solana Ana Beatriz
Department of Computer Science, Technical University of Munich, Garching, Germany.
ASL Europe, GE Healthcare, Munich, Germany.
J Magn Reson Imaging. 2020 Sep;52(3):739-751. doi: 10.1002/jmri.27073. Epub 2020 Feb 19.
Conventional T *-weighted functional magnetic resonance imaging (fMRI) is performed with echo-planar imaging (EPI) sequences that create substantial acoustic noise. The loud acoustic noise not only affects the activation of the auditory cortex, but may also interfere with resting state and task fMRI experiments.
To demonstrate the feasibility of a novel, quiet, T *, whole-brain blood oxygenation level-dependent (BOLD)-fMRI method, termed Looping Star, compared to conventional multislice gradient-echo EPI.
Prospective.
PHANTOM/SUBJECTS: Glover stability QA phantom; 10 healthy volunteers.
FIELD STRENGTH/SEQUENCE: 3.0T: gradient echo (GE)-EPI and T * Looping Star fMRI.
Looping Star fMRI was presented and compared to GE-EPI with a working memory (WM) task and resting state (RS) experiments. Temporal stability and acoustic measurements were obtained for both methods. Functional maps and activation accuracy were compared to evaluate the performance of the novel sequence.
Mean and standard deviation values were analyzed for temporal stability and acoustic noise tests. Activation maps were assessed with one-sample t-tests and contrast estimates (CE). Paired t-tests and receiver operator characteristic (ROC) were used to compare fMRI sensitivity and performance.
Looping Star presented a 98% reduction in sound pressure compared with GE-EPI, with stable temporal stability (0.09% percent fluctuation), but reduced temporal signal-to-noise ratio (tSNR) (mean difference = 15.9%). The novel method yielded consistent activations for RS and WM (83.4% and 69.5% relative BOLD sensitivity), which increased with task difficulty (mean CE 2-back = 0.56 vs. 0-back = 0.08, P < 0.05). A few differences in spatial activations were found between sequences, leading to a 4-8% lower activation accuracy with Looping Star.
Looping Star provides a suitable approach for whole-brain coverage with sufficient spatiotemporal resolution and BOLD sensitivity, with only 0.5 dB above ambient noise. From the comparison with GE-EPI, further developments of Looping Star fMRI should target increased sensitivity and spatial specificity for both RS and task experiments.
1 J. Magn. Reson. Imaging 2020;52:739-751.
传统的T*加权功能磁共振成像（fMRI）是通过回波平面成像（EPI）序列进行的，该序列会产生大量的声学噪声。强烈的声学噪声不仅会影响听觉皮层的激活，还可能干扰静息态和任务fMRI实验。
与传统的多层梯度回波EPI相比，证明一种新型的、安静的、T*全脑血氧水平依赖（BOLD）-fMRI方法——循环星（Looping Star）的可行性。
前瞻性研究。
模型/受试者：格洛弗稳定性质量保证模型；10名健康志愿者。
场强/序列：3.0T：梯度回波（GE）-EPI和T*循环星fMRI。
展示了循环星fMRI，并将其与GE-EPI进行了工作记忆（WM）任务和静息态（RS）实验的比较。获得了两种方法的时间稳定性和声学测量结果。比较了功能图谱和激活准确性，以评估新序列的性能。
分析了时间稳定性和声学噪声测试的均值和标准差。用单样本t检验和对比估计（CE）评估激活图谱。配对t检验和受试者操作特征（ROC）用于比较fMRI的敏感性和性能。
与GE-EPI相比，循环星的声压降低了98%，具有稳定的时间稳定性（波动0.09%），但时间信噪比（tSNR）降低（平均差异=15.9%）。新方法在静息态和工作记忆中产生了一致的激活（相对BOLD敏感性分别为83.4%和69.5%），且随着任务难度增加（平均CE 2-back=0.56 vs. 0-back=0.08，P<0.05）。序列之间在空间激活上存在一些差异，导致循环星的激活准确性降低4-8%。
循环星提供了一种适用于全脑覆盖的方法，具有足够的时空分辨率和BOLD敏感性，仅比环境噪声高0.5dB。与GE-EPI比较后，循环星fMRI的进一步发展应针对提高静息态和任务实验的敏感性和空间特异性。
2级。
1级。《磁共振成像杂志》2020年；52：739-751。
