A systematic optimization of 19F MR image acquisition to detect macrophage invasion into an ECM hydrogel implanted in the stroke-damaged brain
A systematic optimization of 19F MR image acquisition to detect macrophage invasion into an ECM hydrogel implanted in the stroke-damaged brain
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DOI：
10.1016/j.neuroimage.2019.116090
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发表时间：
2019-11-15
期刊：
影响因子：
5.7
通讯作者：
Modo, Michel
中科院分区：
文献类型：
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作者：
Ghuman, Harmanvir;Hitchens, T. Kevin;Modo, Michel
全氟碳(PFC)标记的巨噬细胞的F-19-MR成像可以提供对它们的参与和炎症事件的时空动态的独特洞察，例如植入卒中腔内的细胞外基质(ECM)水凝胶的生物降解。为了确定最有效的F-19-MR成像捕获策略，使用实验设计(DoE)方法对5种常用序列进行了优化，并根据它们的信噪比(SNR)进行了比较。稳态进动快速成像(FISP)序列对F-19信号的探测效率最高，其次是弛豫增强快速捕获序列(REARE)。多层多回波(MSME)、快速低角度激发(闪光)和零回声时间(ZTE)序列的效率明显较低。成像参数(矩阵/体素大小；切片厚度、平均数)通过减少由点扩散函数(PSF)分析确定的部分体积效应来确定对象识别的准确性(即真实性和精确度)。96×96矩阵尺寸(0.35 mm(3))对REARE(2.85 mm PFPE；119 mm F-19)和FISP(0.43 mm PFPE；18.1 mm F-19)产生最低检测限(LOD)，以SNR为2作为检测阈值。PFC标记的巨噬细胞侵入ECM水凝胶的脑模型成像进一步说明了这些参数变化的影响。序列和成像参数的系统优化为准确显示F-19标记的巨噬细胞在大脑中的分布和密度提供了框架。这将加深我们对外周来源的巨噬细胞在生物支架降解中的贡献及其在脑组织再生中的作用的理解。
F-19-MR imaging of perfluorocarbon (PFC)-labeled macrophages can provide a unique insight into their participation and spatio-temporal dynamics of inflammatory events, such as the biodegradation of an extracellular matrix (ECM) hydrogel implanted into a stroke cavity. To determine the most efficient acquisition strategy for F-19-MR imaging, five commonly used sequences were optimized using a design of experiment (DoE) approach and compared based on their signal-to-noise ratio (SNR). The fast imaging with steady-state precession (FISP) sequence produced the most efficient detection of a F-19 signal followed by the rapid acquisition with relaxation enhancement (RARE) sequence. The multi-slice multi-echo (MSME), fast low angle shot (FLASH), and zero echo time (ZTE) sequences were significantly less efficient. Imaging parameters (matrix/voxel size; slice thickness, number of averages) determined the accuracy (i.e. trueness and precision) of object identification by reducing partial volume effects, as determined by analysis of the point spread function (PSF). A 96 x 96 matrix size (0.35 mm(3)) produced the lowest limit of detection (LOD) for RARE (2.85 mM PFPE; 119 mM F-19) and FISP (0.43mM PFPE; 18.1 mM F-19), with an SNR of 2 as the detection threshold. Imaging of a brain phantom with PFC-labeled macrophages invading an ECM hydrogel further illustrated the impact of these parameter changes. The systematic optimization of sequence and imaging parameters provides the framework for an accurate visualization of F-19-labeled macrophage distribution and density in the brain. This will enhance our understanding of the contribution of periphery-derived macrophages in bioscaffold degradation and its role in brain tissue regeneration.