Optimization of DSC MRI Echo Times for CBV Measurements Using Error Analysis in a Pilot Study of High-Grade Gliomas
Optimization of DSC MRI Echo Times for CBV Measurements Using Error Analysis in a Pilot Study of High-Grade Gliomas
复制标题
DOI：
10.3174/ajnr.a5295
复制
发表时间：
2017-09-01
影响因子：
3.5
通讯作者：
Quarles, C. C.
中科院分区：
文献类型：
--
作者：
Bell, L. C.;Does, M. D.;Quarles, C. C.
背景和目的：必须计算最佳TE以最小化DSC MR成像所作的CBV测量的差异。模拟可以用来确定TE对CBV的影响，但它们可能不能充分概括体内平扫T2*的异质性、造影剂动力学以及造影剂诱导T2*变化的生物物理基础。本研究的目的是将定量的MultiECHO DSC MRI T2*时间曲线与误差分析相结合，以计算传统单回声采集的最佳TE。材料和方法：11例高级别胶质瘤患者在3T采用双回波DSC MR成像序列进行扫描，以量化造影剂引起的T2*变化。结果：最佳TE是对比剂团注横跨体素时T2*值的加权平均值。高级别胶质瘤的最佳TES平均值为30.07.4ms，正常白质为36.3+/-4.6ms，动脉输入功能估计值为11.8+/-1.4ms(重复测量ANOVA，P<；.001)。结论：高级别胶质瘤的最佳TES值具有较大的异质性，3种ROI的平均值均有统计学意义。动脉输入功能估计的最佳TE要短得多；这一发现意味着定量DSC MR成像采集将受益于MultiECHO采集。在单回波采集的情况下，规定的最佳TE应为30-35ms(不带预载)和20-30ms(带标准全剂量预载)。
BACKGROUND AND PURPOSE: The optimal TE must be calculated to minimize the variance in CBV measurements made with DSC MR imaging. Simulations can be used to determine the influence of the TE on CBV, but they may not adequately recapitulate the in vivo heterogeneity of precontrast T2*, contrast agent kinetics, and the biophysical basis of contrast agent-induced T2* changes. The purpose of this study was to combine quantitative multiecho DSC MRI T2* time curves with error analysis in order to compute the optimal TE for a traditional single-echo acquisition.MATERIALS AND METHODS: Eleven subjects with high-grade gliomas were scanned at 3T with a dual-echo DSC MR imaging sequence to quantify contrast agent-induced T2* changes in this retrospective study. Optimized TEs were calculated with propagation of error analysis for high-grade glial tumors, normal-appearing white matter, and arterial input function estimation.RESULTS: The optimal TE is a weighted average of the T2* values that occur as a contrast agent bolus transverses a voxel. The mean optimal TEs were 30.0 7.4 ms for high-grade glial tumors, 36.3 +/- 4.6 ms for normal-appearing white matter, and 11.8 +/- 1.4 ms for arterial input function estimation (repeated-measures ANOVA, P < .001).CONCLUSIONS: Greater heterogeneity was observed in the optimal TE values for high-grade gliomas, and mean values of all 3 ROIs were statistically significant. The optimal TE for the arterial input function estimation is much shorter; this finding implies that quantitative DSC MR imaging acquisitions would benefit from multiecho acquisitions. In the case of a single-echo acquisition, the optimal TE prescribed should be 30-35 ms (without a preload) and 20-30 ms (with a standard full-dose preload).