Non-invasive MR thermometry by 2D spectroscopic imaging of the Pr[MOE-DO3A] complex.
Non-invasive MR thermometry by 2D spectroscopic imaging of the Pr[MOE-DO3A] complex.
复制标题
通过 Pr[MOE-DO3A] 复合物的 2D 光谱成像进行无创 MR 测温。
DOI：
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发表时间：
1998
影响因子：
3.1
通讯作者：
Roland Felix
中科院分区：
文献类型：
--
作者：
M. Hentschel;P. Wust;W. Wlodarczyk;T. Frenzel;B. Sander;N. Hosten;Roland Felix
区域热疗的未来进展需要一种实用的无创测温方法。在磁共振断层扫描中，自旋密度、T1 弛豫时间、扩散系数和质子共振频率是测量温度分布的候选指标。当在骨盆区域临床使用时，所有这些方法都会受到不同组织产生的伪影、热疗下的组织改变、生理和随机运动、不均匀性、漂移现象和场不稳定性的影响。在这项研究中，评估了一种顺磁性复合物 Pr[MOE-DO3A]，以镨为中心原子，类似于常见的含钆 MRI 造影剂。其甲氧基侧基在 25 摄氏度下的水共振大约 -24 ppm 的温度依赖性被用来确定含有 9.5 mM Pr[MOE-DO3A] 的圆柱形琼脂模型中的二维温度分布。模型通过水套从外部加热，在整个模型中形成稳定的温度分布。首先，确定了温度与镧系配合物Pr[MOE-DO3A]的甲基化学位移之间的相关性。获得的校准曲线表现出 0.12 +/- 0.01 ppm/℃ 的线性关系，几乎独立于周围介质。采用光谱成像（SI）的空间分辨方法确定局部温度分布。通过窄带激励和二维 16 相位编码步骤获得三个正交切片的二维光谱图像。对于最大空间温度分辨率 (11.2 x 11.2 mm2)，FOV 为 180 mm，所有情况下的切片厚度均为 20 mm。结果表明，在以下条件下每次采集的测量时间约为 5 秒：估计浓度为 1 mmol/l，基质尺寸减小为 8 x 8，重复时间减小为 3 x T1（TR 约为 85 ms）。这些 SI 测量每次采集产生的 SNR 约为 4，测量持续时间为 10-20 秒，相当于每个频谱采集两到四次，对于高温期间的在线温度监测来说似乎足够了。体外数据表明，利用温度敏感的 Pr[MOE-DO3A] 复合物进行光谱温度测量，其治疗实际浓度为 1 mmol/l，适合临床使用。与迄今为止测试的方法（rho、T1、扩散、质子共振）相比，所提出的方法具有不易受伪影影响的独特优势。目前正在使用相同的实验装置研究采用磁共振成像的非侵入式测温的竞争方法。
Future progress in regional hyperthermia requires a practical method for non-invasive thermometry. In magnetic resonance tomography, spin density, T1 relaxation time, diffusion coefficient and proton resonance frequency are candidates to measure temperature distributions. When used clinically in the pelvic region, all these methods are compromized by artifacts arising from different tissues, tissue alterations under hyperthermia, physiological and random movements, inhomogeneities, drift phenomena, and field instabilities. In this study a paramagnetic complex was evaluated, Pr[MOE-DO3A], with praseodymium as central atom, similar to common gadolinium containing MRI contrast media. The temperature dependence of its methoxy side group approximately -24 ppm downfield from the water resonance at 25 degrees C was employed to determine 2-D temperature distributions in a cylindrical agar phantom containing 9.5 mM of Pr[MOE-DO3A]. The phantom was heated externally through a water jacket creating a stationary temperature distribution throughout the phantom. At first, the correlation between temperature and the chemical shift of the methyl group of the lanthanide complex Pr[MOE-DO3A] was determined. Calibration curves obtained exhibited a linear relationship of 0.12 +/- 0.01 ppm/degree C, nearly independent from the surrounding medium. Local temperature distributions were determined employing the spatially resolved method of spectroscopic imaging (SI). 2-D spectroscopic images for three orthogonal slices were obtained by narrow-band excitation and 16 phase encoding steps in two dimensions. The FOV was 180 mm and the slice thickness in all cases was 20 mm for maximal spatial temperature resolution (11.2 x 11.2 mm2). The results indicate a measurement time of about 5s per acquisition under the following conditions: An estimated concentration of 1 mmol/l, a reduced matrix size of 8 x 8, and a reduced repetition time of 3 x T1 (TR approximately 85 ms). Those SI measurements produced a SNR of approximately 4 per acquisition, a measurements duration of 10-20 s, equivalent to two to four acquisitions per spectrum, seem sufficient for online temperature monitoring during hyperthermia. The in vitro data suggest the spectroscopic temperature measurement utilizing a temperature-sensitive Pr[MOE-DO3A] complex with a therapeutically realistic concentration of 1 mmol/l to be suitable for clinical use. Compared to the methods tested so far (rho, T1, diffusion, proton resonance), the method presented has the unique advantage of being less susceptible to artifacts. The competing methods of non-invasive thermometry employing magnetic resonance imaging are currently being investigated using the same experimental setup.
DOI：
10.3109/02656739209021781
发表时间：
1992-03
期刊：
International journal of hyperthermia : the official journal of European Society for Hyperthermic Oncology, North American Hyperthermia Group
影响因子：
--
作者：
Y. Zhang;T. Samulski;W. Joines;J. Mattiello;R. L. Levin;D. LeBihan
通讯作者：
Y. Zhang;T. Samulski;W. Joines;J. Mattiello;R. L. Levin;D. LeBihan
影响因子：
3.8
作者：
PARKER, DL;SMITH, V;FUSSELL, L
通讯作者：
FUSSELL, L
影响因子：
19.7
作者：
POSSE, S;DECARLI, C;LEBIHAN, D
通讯作者：
LEBIHAN, D