Ra J B, Hilal S K, Oh C H
Department of Radiology, Columbia University, New York, NY 10032.
J Comput Assist Tomogr. 1989 Mar-Apr;13(2):302-9. doi: 10.1097/00004728-198903000-00022.
Multiecho magnetic resonance imaging of 23Na in the human body could provide valuable information regarding the distribution of the sodium in the intracellular and extracellular spaces in living tissues. Since it is known that more than half the intracellular sodium has a T2 value of less than 3 ms, the conventional spin-echo imaging technique is not appropriate for the quantitative study of sodium in living tissues. A pulse sequence using the three-dimensional planar-integral projection reconstruction algorithm was developed to provide images from the free induction decay (FID) signal and from the spin-echo. Using this imaging sequence, we are able to produce human head images with the FID signal immediately following the 90 degrees radiofrequency pulse thus preserving the signal from the very short T2 components. This technique with a multiple echo imaging scheme may open the possibility of discriminating between intracellular and extracellular sodium compartments in the human brain based on the T2 relaxation properties.
人体23Na的多回波磁共振成像能够提供有关活体组织细胞内和细胞外空间钠分布的有价值信息。由于已知超过一半的细胞内钠的T2值小于3毫秒，传统的自旋回波成像技术不适用于活体组织中钠的定量研究。开发了一种使用三维平面积分投影重建算法的脉冲序列，以从自由感应衰减（FID）信号和自旋回波中获取图像。使用这种成像序列，我们能够在90度射频脉冲之后立即用FID信号生成人类头部图像，从而保留来自极短T2成分的信号。这种具有多回波成像方案的技术可能会基于T2弛豫特性区分人脑中细胞内和细胞外钠区室。
