Graham G D, Hwang J H, Rothman D L, Prichard J W
Department of Neurology, University of New Mexico School of Medicine and Albuquerque VA Hospital, Albuquerque, NM, USA.
Stroke. 2001 Dec 1;32(12):2797-802. doi: 10.1161/hs1201.099414.
We sought to measure the temporal evolution and spatial distribution of lesion macromolecules and small molecules (lactate, N-acetyl compounds, creatine, and choline) in stroke patients by using short echo time in vivo proton MR spectroscopy.
Single-voxel spectra with TE=22 ms were obtained with and without inversion recovery suppression of small-molecule resonances from 30 examinations of 24 patients 3 to 214 days after stroke. Subtraction of the suppressed from the unsuppressed spectra yielded metabolite spectra without overlap from macromolecules. Two-dimensional spectroscopic images were acquired with macromolecule and small-molecule suppression from 5 additional patients.
Macromolecule signals were elevated in lesions relative to normal brain and tended to increase in the subacute period, even as lactate peaks declined. Regions of increased lactate, increased macromolecule signal at 1.3 ppm, and decreased N-acetyl compounds were closely correlated in the 2D spectroscopic images.
Short echo time spectra can be acquired in vivo in a manner that improves signal-to-noise ratio over long echo experiments and resolves overlapping macromolecule and small-molecule signals. The prominent macromolecule signals seen in the subacute period in association with persistently elevated lactate may represent mobile lipids in macrophages or other cells.
我们试图通过使用短回波时间的活体质子磁共振波谱来测量中风患者病变中大分子和小分子（乳酸、N - 乙酰化合物、肌酸和胆碱）的时间演变和空间分布。
在中风后3至214天对24例患者进行30次检查，分别在有和没有小分子共振反转恢复抑制的情况下获得TE = 22 ms的单体素质子磁共振波谱。从未抑制的波谱中减去抑制后的波谱，得到无大分子重叠的代谢物波谱。另外对5例患者进行了有大分子和小分子抑制的二维磁共振波谱成像。
相对于正常脑组织，病变中的大分子信号升高，并且在亚急性期有增加的趋势，即便乳酸峰下降。在二维磁共振波谱成像中，乳酸增加区域、1.3 ppm处大分子信号增加区域以及N - 乙酰化合物减少区域密切相关。
短回波时间波谱可以在活体中采集，与长回波实验相比能提高信噪比，并能分辨重叠的大分子和小分子信号。在亚急性期观察到的与乳酸持续升高相关的显著大分子信号可能代表巨噬细胞或其他细胞中的可移动脂质。
