Efficient phase-cycling strategy for high-resolution 3D gradient-echo quantitative parameter mapping.
Efficient phase-cycling strategy for high-resolution 3D gradient-echo quantitative parameter mapping.
复制标题
高分辨率三维梯度回波定量参数映射的高效相位循环策略
作者：
磁化准备 (MP) 梯度回波 (GRE) 序列在读出序列期间会因恢复而受到信号污染，这可以通过成对射频相位循环 (PC) 来消除，但代价是扫描时间加倍。本研究的目的是开发并验证一种新颖的不配对 PC 策略，以消除 3D MP-GRE 序列中高分辨率定量参数映射的时间损失。根据观察，GRE 读出序列中的污染恢复信号与 MP 无关，可以使用复杂值数据的新型曲线拟合方法来消除其影响，而无需配对 PC 采集。使用磁化准备的角度调制分区 k 空间破坏梯度回波快照 (MAPSS) 映射序列，在 3T 的体模和体内人体膝关节研究中，将四种新的未配对 PC 方案与两种传统配对 PC 方案进行了比较。在模型研究中，当均匀时，所有方法都会在中心切片处产生一致的测量结果。当包含非理想的偏心切片时，结果不一致。与配对 PC 方案相比，两个未配对的 PC 方案具有相当或显着提高的定量准确性和扫描-重扫描再现性。使用新的不配对 PC 方案，没有显着的数量变异性增加或空间保真度损失。未配对的 PC 在不同的频率偏移下也有不同的光谱响应，这可能会被用来降低对场不均匀性的敏感度。人类膝关节研究结果与模型研究结果一致。总之，与配对 PC 方法相比，不配对 PC 策略可能允许更准确的定量参数映射，并且扫描时间减半，从而消除恢复中的信号污染。因此，它在信噪比优化、空间分辨率提高以及成像采样点选择方面提供了额外的灵活性，以获得更准确的定量参数映射。提出了一种新颖的不配对 PC 策略，以消除 3D MP-GRE 序列中高分辨率定量映射的时间损失。与传统的配对 PC 方案相比，未配对 PC 具有相当或更高的定量精度，并降低了对非理想条件的敏感性，而不会增加定量变异性或空间保真度损失。因此，它在信噪比优化、空间分辨率提高和成像采样点选择方面提供了额外的灵活性，以获得更准确的快速定量映射。
Magnetization-Prepared (MP) gradient-echo (GRE) sequences suffer from signal contaminations from recovery during the readout train, which can be eliminated by paired RF phase cycling (PC) at the cost of doubling the scan time. The objective of this study was to develop and validate a novel unpaired PC strategy to eliminate the time penalty for high resolution quantitative parameter mapping in 3D MP-GRE sequences. Based on the observation that the contaminating recovery signal along in the GRE readout train is independent of MP, its impact can be eliminated using a novel curve-fitting approach with complex-valued data without needing paired PC acquisitions. Four new unpaired PC schemes were compared against two traditional paired PC schemes in both phantom and in vivo human knee studies at 3T using a magnetization-prepared angle-modulated partitioned k-space spoiled gradient-echo snapshots (MAPSS) mapping sequence. In the phantom study, all methods resulted in consistent measurements at the center slice when were uniform. Results were not consistent when off-center slices with non-ideal were included. Two unpaired PC schemes had comparable or significantly improved quantitative accuracy and scan-rescan reproducibility compared with the paired PC schemes. There was no significant quantitative variability increase or spatial fidelity loss using the new unpaired PC schemes. Unpaired PC also had different spectral response at different frequency offset, which can potentially be exploited to reduce sensitivity to field inhomogeneities. Human knee study results were consistent with the phantom study findings. In conclusion, unpaired PC strategy potentially allows more accurate quantitative parameter mapping with halved scan time compared with the paired PC approach to eliminate signal contaminations from recovery. It therefore offers additional flexibility in SNR optimization, spatial resolution improvement, and choice of imaging sampling points to obtain more accurate quantitative parameter mapping. A novel unpaired PC strategy is presented to eliminate the time penalty for high-resolution quantitative mapping in 3D MP-GRE sequences. The unpaired PC had comparable or improved quantitative accuracy and reduced sensitivity to non-ideal conditions without increasing quantitative variability or loss of spatial fidelity compared to the traditional paired PC schemes. It therefore offers additional flexibility in SNR optimization, spatial resolution improvement, and choice of imaging sampling points to obtain more accurate fast quantitative mapping.
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影响因子：
7
作者：
Kim J;Mamoto K;Lartey R;Xu K;Nakamura K;Shin W;Winalski CS;Obuchowski N;Tanaka M;Bahroos E;Link TM;Hardy PA;Peng Q;Reddy R;Botto-van Bemden A;Liu K;Peters RD;Wu C;Li X
通讯作者：
Li X
影响因子：
3.3
作者：
MUGLER, JP;EPSTEIN, FH;BROOKEMAN, JR
通讯作者：
BROOKEMAN, JR
影响因子：
5
作者：
Gold, GE;Han, E;Beaulieu, C
通讯作者：
Beaulieu, C
影响因子：
6
作者：
Haris M;Singh A;Cai K;Davatzikos C;Trojanowski JQ;Melhem ER;Clark CM;Borthakur A
通讯作者：
Borthakur A
影响因子：
4.2
作者：
Filip, Pavel;Svatkova, Alena;Mangia, Silvia
通讯作者：
Mangia, Silvia