Woermann F G, Steiner H, Barker G J, Bartlett P A, Elger C E, Duncan J S, Symms M R
Epilepsy Research Group, Institute of Neurology, London, UK.
J Magn Reson Imaging. 2001 Apr;13(4):547-52. doi: 10.1002/jmri.1077.
To evaluate the use of cerebrospinal fluid (CSF) signal nulling in MR T2 measurements of the hippocampus in normal control subjects and patients with temporal lobe epilepsy (TLE), dual-echo acquisitions covering the whole brain were used. T2 relaxation times were estimated in 12 standard Eurospin II MR test objects and in the hippocampi of 10 control subjects, using T2 maps constructed from conventional spin-echo (CSE), fast spin-echo (FSE), and fast FLAIR (FF) dual-echo sequences on a 1.5-T MR scanner. Hippocampal T2 values (HCT2) were measured on contiguous coronal 5-mm slices throughout the antero-posterior extent of each hippocampus in the 10 controls and 12 TLE patients, using both CSE and FF. Scan-rescan reproducibility in Eurospin II standard MR test objects was high for all sequences. There was a good correlation between T2 values from CSE, FF, and FSE sequences in test objects and in control hippocampi. In controls, the coefficient of variation of mean HCT2 values differed between slice positions, but was lowest for FF, followed by CSE data. The intrarater coefficient of reliability between repeated measurements in control subjects was lowest for FF HCT2, at 2.3%. The interrater coefficient of reliability for CSE HCT2 measurements in controls (4.8%) was slightly lower than the interrater coefficient for FF HCT2 (5.4%). HCT2 measurement with both CSE and FF identified abnormal values in the same 10 hippocampi of 12 patients. Hippocampal dual-echo T2 relaxometry using CSF nulling is reliable in control subjects, and identifies the abnormal hippocampi in patients with TLE. The increases in hippocampal T2 signal demonstrated using FF HCT2 measurements are unlikely to be partial volume effects from CSF.
为评估脑脊液（CSF）信号抑制在正常对照受试者和颞叶癫痫（TLE）患者海马区磁共振T2测量中的应用，采用覆盖全脑的双回波采集。在1.5-T磁共振扫描仪上，利用传统自旋回波（CSE）、快速自旋回波（FSE）和快速液体衰减反转恢复（FF）双回波序列构建的T2图，对12个标准Eurospin II磁共振测试体模以及10名对照受试者的海马区进行T2弛豫时间估计。在10名对照者和12名TLE患者的每个海马区的前后范围，使用CSE和FF在连续的5毫米冠状切片上测量海马T2值（HCT2）。所有序列在Eurospin II标准磁共振测试体模中的扫描-重扫重复性都很高。测试体模和对照海马区中CSE、FF和FSE序列的T2值之间具有良好的相关性。在对照者中，平均HCT2值的变异系数在不同切片位置有所不同，但FF最低，其次是CSE数据。对照受试者重复测量中FF HCT2的评分者内可靠性系数最低，为2.3%。对照者中CSE HCT2测量的评分者间可靠性系数（4.8%）略低于FF HCT2的评分者间可靠性系数（5.4%）。CSE和FF测量的HCT2在12名患者的相同10个海马区均识别出异常值。使用CSF抑制的海马双回波T2弛豫测量法在对照受试者中是可靠的，并且能够识别TLE患者异常的海马区。使用FF HCT2测量显示的海马T2信号增加不太可能是CSF的部分容积效应。
