Rapid combined T1 and T2 mapping using gradient recalled acquisition in the steady state
Rapid combined T1 and T2 mapping using gradient recalled acquisition in the steady state
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DOI：
10.1002/mrm.10407
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发表时间：
2003-03-01
影响因子：
3.3
通讯作者：
Peters, TM
中科院分区：
文献类型：
--
作者：
Deoni, SCL;Rutt, BK;Peters, TM
提出了一种新的、全三维、高分辨率的T-1和T-2弛豫时间映射方法。该方法是基于稳态成像与T-1和T-2的信息，从任何破坏或完全重新聚焦的横向磁化后，每个激励脉冲。T-1是从一对扰相梯度回波（SPGR）图像采集优化翻转角。该T-1信息与两个重聚焦稳态自由进动（SSFP）图像相结合，以确定T-2。分别根据反转恢复（IR）和自旋回波（SE）结果评价T-1和T-2准确度。根据体模和体内测量确定的T-1和T-2标测图内的误差，对于300和2000 ms之间的T-1，约为7%（.）T-2在30和150 ms之间为7%。该方法的效率，定义为每平方根扫描时间每体素体积的最终标测图的信噪比（SNR），与替代标测方法进行了评价。多点IR的三倍和多回波SE的三倍的效率，我们的组合方法是最有效的检查。全脑T-1图（25 x 25 x 10 cm）的采集时间小于8 min，具有1 mm（3）各向同性体素。对于相同大小的T-2图，需要额外的7分钟，并且在1 GHz Pill PC上的后处理时间小于1分钟。因此，该方法首次允许全脑T-1和T-2图的实时临床采集和显示。(C)2003 Wiley-Liss，Inc.
A novel, fully 3D, high-resolution T-1 and T-2 relaxation time mapping method is presented. The method is based on steadystate imaging with T-1 and T-2 information derived from either spoiling or fully refocusing the transverse magnetization following each excitation pulse. T-1 is extracted from a pair of spoiled gradient recalled echo (SPGR) images acquired at optimized flip angles. This T-1 information is combined with two refocused steady-state free precession (SSFP) images to determine T-2. T-1 and T-2 accuracy was evaluated against inversion recovery (IR) and spin-echo (SE) results, respectively. Error within the T-1 and T-2 maps, determined from both phantom and in vivo measurements, is approximately 7% for T-1 between 300 and 2000 ms(.) and 7% for T-2 between 30 and 150 ms. The efficiency of the method, defined as the signal-to-noise ratio (SNR) of the final map per voxel volume per square root scan time, was evaluated against alternative mapping methods. With an efficiency of three times that of multipoint IR and three times that of multi-echo SE, our combined approach represents the most efficient of those examined. Acquisition time for a whole brain T-1 map (25 x 25 x 10 cm) is less than 8 min with 1 mm(3) isotropic voxels. An additional 7 min is required for an identically sized T-2 map and postprocessing time is less than 1 min on a 1 GHz Pill PC. The method therefore permits real-time clinical acquisition and display of whole brain T-1 and T-2 maps for the first time. (C) 2003 Wiley-Liss, Inc.