Combined T2* and T1 measurements for improved perfusion and permeability studies in high field using dynamic contrast enhancement
Combined T2* and T1 measurements for improved perfusion and permeability studies in high field using dynamic contrast enhancement
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DOI：
10.1007/s00330-006-0198-1
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发表时间：
2006-09-01
影响因子：
5.9
通讯作者：
Alsop, David C.
中科院分区：
文献类型：
--
作者：
de Bazelaire, Cedric;Rofsky, Neil M.;Alsop, David C.
本研究使用高场强下的 T1 加权序列分析了肿瘤研究期间动脉血中细胞外分布的钆造影剂的 T2* 效应。采用回波时间为 1.5 和 3.5 ms 的饱和双回波序列，在 3 T 下同时表征 28 名身体肿瘤患者在推注 Gd-DTPA 期间动脉血的 T1 和 T2*。在不同浓度造影剂的人血样本中校准了 Gd-DTPA 对全血图像强度的 T2* 效应和 T1 效应。 T2* 用于估计推注峰值附近的浓度。当 T2* 不显着时，T1 用于测量较低浓度。 T2* 可在 Gd-DTPA 浓度高于 4 mM 的校准曲线上测量。 18 名患者的浓度超出了这一浓度。由于 T2* 效应导致的平均信号强度降低估计为 T2* 补偿信号的 22 +/- 14%。使用 T2* 测量减少了对动脉峰值 Gd-DTPA 浓度 (59 +/- 38%) 的低估和对渗透性 K-trans 的高估 (58%)。因此，在高场强下使用 T1 加权序列进行肿瘤研究时，应考虑钆造影剂的 T2* 效应。
This study analyzed the T2* effect of extracellularly distributed gadolinium contrast agents in arterial blood during tumor studies using T1-weighted sequences at high field strength. A saturation-prepared dual echo sequence with echo times of 1.5 and 3.5 ms was employed at 3 T to simultaneously characterize T1 and T2* of arterial blood during bolus administration of Gd-DTPA in 28 patients with body tumors. T2* effect and T1 effect of Gd-DTPA on image intensity of whole blood were calibrated in human blood samples with different concentrations of contrast agent. T2* was used to estimate concentration near the peak of the bolus. T1 was used to measure lower concentrations when T2* was not significant. T2* was measurable on calibration curves for Gd-DTPA concentrations higher than 4 mM. This concentration was exceeded in 18 patients. The mean signal intensity reduction because of T2* effect was estimated at 22 +/- 14% of the T2* compensated signal. Using T2* measurements reduced underestimations of peak arterial Gd-DTPA concentration (59 +/- 38%) and overestimation of permeability K-trans (58%). The T2* effect of gadolinium contrast agents should therefore be accounted for when performing tumors study with T1-weighted sequences at high field strength.