ERRORS IN T1-DETERMINATION USING MULTISLICE TECHNIQUE AND GAUSSIAN SLICE PROFILES
ERRORS IN T1-DETERMINATION USING MULTISLICE TECHNIQUE AND GAUSSIAN SLICE PROFILES
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DOI：
10.1016/0730-725x(88)90523-1
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发表时间：
1988-01-01
影响因子：
2.5
通讯作者：
PFANNENSTIEL, P
中科院分区：
文献类型：
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作者：
JUST, M;HIGER, HP;PFANNENSTIEL, P
通常使用不同TR-和ti -倍的多层SE-或ir -序列来确定组织特征的T1-和t2值。为了研究序列激励对多片技术的扰动影响，我们测量了信号强度，并计算了幻象的t1值作为相邻片间隙宽度的函数。幻影中含有不同T1的液体。我们发现，当T1/ tr比大于0.3-0.4时，信号强度和计算的T1值对间隙宽度有很强的依赖性。在这种情况下，t1值被大大高估，而t2值不受顺序激励的影响。我们得出结论，可靠的t1测量需要相邻切片之间大于1层厚度的大间距。
Multislice SE- or IR-sequences with different TR- and TI-times, respectively, are often used, to determine T1- and T2-values for tissue characterisation. To investigation the perturbating influence of the sequential excitation in multislice technique, we measured the signal intensities and calculated the T1-values of phantoms as a function of gap widths between neighboured slices. Phantoms contained fluids of different T1. We found a strong dependence of signal intensities and therefore of calculated T1-values on the gap width, when a T1/TR-ratio of more than 0.3-0.4 was reached. T1-values are considerably overestimated in this case, whereas T2-values are not influenced by the sequential excitation. We conclude that reliable T1-measurements necessitate a large spacing of more than 1 slice thickness between adjacent slices.