Rapid magnetic resonance quantification on the brain: Optimization for clinical usage
Rapid magnetic resonance quantification on the brain: Optimization for clinical usage
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DOI：
10.1002/mrm.21635
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发表时间：
2008-08-01
影响因子：
3.3
通讯作者：
Lundberg, P.
中科院分区：
文献类型：
--
作者：
Warnties, J. B. M.;Leinhard, O. Dahlqvist;Lundberg, P.
本文提出了一种能同时快速测量纵向T-1弛豫、横向T-2弛豫、质子密度(PD)和局域射电频率B_1场幅值的方法。通过多切片、多ECHO和多延迟采集，在一次扫描中测量所有四个参数。它是基于先前报道的一种方法，该方法在常规临床应用中得到了实质性的改进。改进包括使用多切片自旋回波技术、背景相位校正和自旋系统模拟来补偿切片选择性RF脉冲轮廓效应。优化的目的是在临床可接受的时间内实现磁共振参数量化的最佳结果。其中一个基准是在5分钟内对大脑进行高分辨率覆盖。在此扫描时间内，一组志愿者测量的受试者间标准偏差(SID)为2%至8%，取决于组织(体素大小=0.8x0.8x5 mm)。作为一个例子，该方法被应用于多发性硬化症患者，其中的病变组织可以明显地与健康参考值区分开来。此外，还表明，使用合成MRI的方法，可以在同一扫描的基础上生成准确的常规对比图像以及量化地图。
A method is presented for rapid simultaneous quantification of the longitudinal T-1 relaxation, the transverse T-2 relaxation, the proton density (PD), and the amplitude of the local radio frequency B, field. All four parameters are measured in one single scan by means of a multislice, multiecho, and multidelay acquisition. It is based on a previously reported method, which was substantially improved for routine clinical usage. The improvements comprise of the use of a multislice spin-echo technique, a background phase correction, and a spin system simulation to compensate for the slice-selective RF pulse profile effects. The aim of the optimization was to achieve the optimal result for the quantification of magnetic resonance parameters within a clinically acceptable time. One benchmark was high-resolution coverage of the brain within 5 min. In this scan time the measured intersubject standard deviation (SID) in a group of volunteers was 2% to 8%, depending on the tissue (voxel size = 0.8 x 0.8 x 5 mm). As an example, the method was applied to a patient with multiple sclerosis in whom the diseased tissue could clearly be distinguished from healthy reference values. Additionally it was shown that, using the approach of synthetic MRI, both accurate conventional contrast images as well as quantification maps can be generated based on the same scan.