In Vivo 31P MR Spectroscopic Imaging of the Human Prostate at 7 T: Safety and Feasibility
In Vivo 31P MR Spectroscopic Imaging of the Human Prostate at 7 T: Safety and Feasibility
复制标题
DOI：
10.1002/mrm.24175
复制
发表时间：
2012-11-01
影响因子：
3.3
通讯作者：
Scheenen, Tom W. J.
中科院分区：
文献类型：
--
作者：
Kobus, Thiele;Bitz, Andreas K.;Scheenen, Tom W. J.
人类前列腺的 P-31 MR 光谱成像提供了有关磷酸化代谢物的信息，可用于前列腺癌的表征。 7 T 磁场强度的灵敏度可以在临床可接受的测量时间内实现具有相关空间分辨率的 3D P-31 MR 光谱成像。为此，开发了 P-31 直肠内线圈，并将其与八通道 H-1 身体阵列线圈相结合，将代谢信息与解剖位置联系起来。进行了广泛的安全验证，以评估两个线圈的比吸收率、射频场分布和温度分布。该验证包括详细的有限积分技术模拟，并通过 MR 测温法和体模中的 B-1(+) 测量以及体内温度测量进行确认。安全性研究表明，P-31 直肠内线圈的存在对外部八通道 H-1 阵列线圈的比吸收率水平和温度分布没有影响。为了将 10 g 平均局部比吸收率保持在 10 W/kg 之内，H-1 阵列线圈允许的最大时间平均输入功率为 33 W。对于使用 P-31 直肠内线圈进行传输，在 15 分钟的 MR 光谱成像实验中，我们在 1.9 W 的时间平均输入功率下达到了体内温度升高不到 1 摄氏度的安全极限。采用此功率设置，对健康志愿者进行了第二次体内测量。使用绝热激发，3D P-31 MR 光谱成像可在 18 分钟内生成整个前列腺的光谱，空间分辨率为 4 cm(3)。光谱分辨率使得能够单独检测磷酸胆碱、磷酸乙醇胺、无机磷酸盐和其他可能在前列腺癌表征中发挥重要作用的代谢物。 Magn Reson Med 68:1683-1695, 2012。(C) 2012 Wiley periodicals, Inc.
P-31 MR spectroscopic imaging of the human prostate provides information about phosphorylated metabolites that could be used for prostate cancer characterization. The sensitivity of a magnetic field strength of 7 T might enable 3D P-31 MR spectroscopic imaging with relevant spatial resolution in a clinically acceptable measurement time. To this end, a P-31 endorectal coil was developed and combined with an eight-channel H-1 body-array coil to relate metabolic information to anatomical location. An extensive safety validation was performed to evaluate the specific absorption rate, the radiofrequency field distribution, and the temperature distribution of both coils. This validation consisted of detailed Finite Integration Technique simulations, confirmed by MR thermometry and B-1(+) measurements in a phantom and in vivo temperature measurements. The safety studies demonstrated that the presence of the P-31 endorectal coil had no influence on the specific absorption rate levels and temperature distribution of the external eight-channel H-1 array coil. To stay within a 10 g averaged local specific absorption rate of 10 W/kg, a maximum time-averaged input power of 33 W for the H-1 array coil was allowed. For transmitting with the P-31 endorectal coil, our safety limit of less than 1 degrees C temperature increase in vivo during a 15-min MR spectroscopic imaging experiment was reached at a time-averaged input power of 1.9 W. With this power setting, a second in vivo measurement was performed on a healthy volunteer. Using adiabatic excitation, 3D P-31 MR spectroscopic imaging produced spectra from the entire prostate in 18 min with a spatial resolution of 4 cm(3). The spectral resolution enabled the separate detection of phosphocholine, phosphoethanolamine, inorganic phosphate, and other metabolites that could play an important role in the characterization of prostate cancer. Magn Reson Med 68:1683-1695, 2012. (C) 2012 Wiley Periodicals, Inc.