A new paramagnetically shifted imaging probe for MRI.
A new paramagnetically shifted imaging probe for MRI.
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DOI：
10.1002/mrm.26185
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发表时间：
2017-03
影响因子：
3.3
通讯作者：
Blamire AM
中科院分区：
文献类型：
--
作者：
Senanayake PK;Rogers NJ;Finney KN;Harvey P;Funk AM;Wilson JI;O'Hogain D;Maxwell R;Parker D;Blamire AM
目的研制一种新型顺磁性磁共振分子成像造影剂。开发了一种造影剂，用于通过镝（III）复合物中两个化学等效叔丁基报告基团的顺磁位移质子磁共振进行直接MRI检测。该复合物在体模中进行表征，并在生理完整的小鼠中在7特斯拉（T）下使用三维（3D）梯度回波和光谱成像（MRSI）序列进行成像，以测量空间分布和信号频率。报告子质子位于顺磁中心的1.65 μ m处，导致快速T1弛豫（T1 = 8 ms）和超过60 ppm的大顺磁频移。快速弛豫允许短的扫描重复时间与高激发翻转角，导致高灵敏度。大的偶极位移允许直接频率选择性激发和收购的镝（III）复合物，独立的组织水信号。在单次低剂量静脉注射后，以62 s的时间分辨率在体内跟踪复合物的生物学行为。检测浓度下限为1023 μM。通过MRSI，利用顺磁位移（0.28 ppm.K-1）的温度依赖性来检查组织温度变化。这些数据证明了一种新的MRI试剂，具有通过MRI进行生理监测的潜力。Magn Reson Med 77：1307-1317，2017。© 2016 The Authors Magnetic Resonance in Medicine出版由Wiley Periodicals，Inc.国际医学磁共振学会（International Society for Magnetic Resonance in Medicine）这是一个开放获取的条款下的知识共享署名许可证，允许使用，分发和复制在任何媒体上，只要原始作品是适当的引用。
To develop and characterize a new paramagnetic contrast agent for molecular imaging by MRI. A contrast agent was developed for direct MRI detection through the paramagnetically shifted proton magnetic resonances of two chemically equivalent tert‐butyl reporter groups within a dysprosium(III) complex. The complex was characterized in phantoms and imaged in physiologically intact mice at 7 Tesla (T) using three‐dimensional (3D) gradient echo and spectroscopic imaging (MRSI) sequences to measure spatial distribution and signal frequency. The reporter protons reside ∼6.5 Å from the paramagnetic center, resulting in fast T 1 relaxation (T 1 = 8 ms) and a large paramagnetic frequency shift exceeding 60 ppm. Fast relaxation allowed short scan repetition times with high excitation flip angle, resulting in high sensitivity. The large dipolar shift allowed direct frequency selective excitation and acquisition of the dysprosium(III) complex, independent of the tissue water signal. The biokinetics of the complex were followed in vivo with a temporal resolution of 62 s following a single, low‐dose intravenous injection. The lower concentration limit for detection was ∼23 μM. Through MRSI, the temperature dependence of the paramagnetic shift (0.28 ppm.K−1) was exploited to examine tissue temperature variation. These data demonstrate a new MRI agent with the potential for physiological monitoring by MRI. Magn Reson Med 77:1307–1317, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.