Accelerated 3D-GRASE imaging improves quantitative multiple post labeling delay arterial spin labeling
Accelerated 3D-GRASE imaging improves quantitative multiple post labeling delay arterial spin labeling
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DOI：
10.1002/mrm.27226
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发表时间：
2018-12-01
影响因子：
3.3
通讯作者：
Stoecker, Tony
中科院分区：
文献类型：
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作者：
Boland, Markus;Stirnberg, Ruediger;Stoecker, Tony
目的：研究加速、单次 3D-GRASE 采集对具有多个和单次标记后延迟 (PLD) 的定量动脉自旋标记 (ASL) 在每单位扫描时间灌注加权 SNR (TSNRPW) 和量化精度方面的影响。方法：使用伪连续动脉自旋标记 (PCASL) 技术和能够并行成像加速的 3D-GRASE 成像序列，在 3T MRI 扫描仪上对 5 名受试者进行扫描。在序列中模拟并实现了 3 反转脉冲背景抑制。三个时间匹配的单个 PLD 测量（其中一个没有加速的分段测量、1 个使用传统 GRAPPA 测量、1 个使用 CAIPIRINHA 采样）用于比较 TSNRPW。另外还评估了具有相同成像参数的三个时间匹配的多个 PLD 测量（无加速与 CAIPIRINHA 采样与具有双倍 PLD 数量的 CAIPIRINHA 采样）。比较脑血流和动脉传输时间拟合的不确定性，并将其用作质量测量。结果：单次 PLD 测量显示，使用 CAI-PIRINHA 采样代替 GRAPPA 采样，TSNRPW 增加了 11%，而非加速扫描的 TSNRPW 比 GRAPPA 扫描高 35%。然而，利用多个 PLD 采集的平均值数量的增加，与无加速相比，使用 CAIPIRINHA 采样（6 个 PLD/12 个 PLD）观察到 CBF 拟合不确定性减少了 14%/16%（灰质）和 34%/36%（白质）。结论：使用 PCASL 加速单次 3D-GRASE 允许比时间匹配分段采集更小的量化不确定性。相应的单次采集具有可接受的模糊性并且没有体积内运动，使得在临床可行的时间内最先进的 ASL 方法成为可能。
Purpose: To investigate the impact of accelerated, single-shot 3D-GRASE acquisition on quantitative arterial spin labeling (ASL) with multiple and single post-labeling delay (PLD) in terms of perfusion-weighted SNR per unit scan time (TSNRPW) and quantification accuracy.Methods: Five subjects were scanned on a 3T MRI scanner using the pseudo-continuous arterial spin labeling (PCASL) technique with a 3D-GRASE imaging sequence capable of parallel imaging acceleration. A 3-inversion pulse background suppression was simulated and implemented in the sequence. Three time-matched single PLD measurements, a segmented one without acceleration, 1 with conventional GRAPPA, and 1 with CAIPIRINHA sampling, were used to compare TSNRPW. Three time-matched multiple PLD measurements with the identical imaging parameters were additionally evaluated (no acceleration vs. CAIPIRINHA sampling vs. CAIPIRINHA sampling with doubled number of PLDs). Cerebral blood flow and arterial transit time fit uncertainties were compared and used as a quality measure.Results: The single PLD measurements show an 11% TSNRPW increase using CAI-PIRINHA sampling instead of GRAPPA sampling, while the non-accelerated scan exhibits 35% higher TSNRPW compared to the GRAPPA scan. However, taking advantage of the increased number of averages for multiple PLD acquisitions, a 14%/16% (gray matter) and 34%/36% (white matter) reduction of CBF fit uncertainty is observed with CAIPIRINHA sampling (6 PLDs/12 PLDs) compared to no acceleration.Conclusion: Accelerated single-shot 3D-GRASE with PCASL allows for smaller quantification uncertainties than time-matched segmented acquisitions. Corresponding single-shot acquisitions with acceptable blurring and no intra-volume motion render state-of-the-art ASL methods in a clinically feasible time possible.