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时间分割复杂化 (TDM) 序列消除了T₂估计和放松-扩散测量的偏差

Qiang Liu^1,2, Borjan Gagoski^3,4, Imam Ahmed Shaik¹

¹Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.

Magnetic resonance in medicine

|August 13, 2024

概括

时间分割复杂化 (TDM) 提供了准确的加速放松扩散MRI (rdMRI) 微结构测量,优于多回声 (ME) 序列. TDM提供可靠的rdMRI数据与2-3倍的加速,不像ME显示显著偏差.

科学领域:

磁共振成像技术磁共振成像技术
生物物理学的生物物理.
医学物理医学物理

背景情况:

加速MRI技术对于减少扩散MRI (dMRI) 和基于放松成像的扫描时间至关重要.
放松-扩散MRI (rdMRI) 结合了扩散和T2放松测量以探测组织微观结构.
对比采集序列对于优化rdMRI性能和可靠性至关重要.

研究的目的:

为了比较加速rdMRI的多回声 (ME) 和时间分割复杂化 (TDM) 序列.
评估TDM和ME序列在估计rdMRI微结构测量的准确性和可靠性.
评估加速因子对序列性能的影响.

主要方法:

ME,TDM和单回声 (SE) 序列使用Pulseq实现了单频段 (SB) 和多频段2 (MB2) 加速.
进行了幻影和体内脑部扫描,以比较图像强度和T2估计.
使用放松扩散成像时刻 (REDIM) 和最大放松扩散分布 (MaxEnt-RDD) 评估了微观结构估计.

主要成果:

TDM的业绩与SE收购的黄金标准差不多.
与SE相比,ME序列表现出明显更大的偏差 (3-4x在幻体上,2x in-vivo)
TDM为SE提供了可比的扩散和放松参数,而ME在R2图和放松-扩散共变量中显示了实质性的偏差.

结论:

时间分割多重复合 (TDM) 序列提供准确可靠的放松-扩散MRI微结构测量.
在不影响数据质量的情况下,TDM能够以2-3倍的因子加速rdMRI采集.
由于偏差较高,ME序列对于准确的rdMRI微结构估计的可靠性较低.

关键词:

Pulseq 的意思是脉冲.这是一个dMRI.扩散扩散是一种扩散.这是一个多维的MRI.在rdMRI中使用.放松度计放松度计放松度计.

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