Hetherington H P, Mason G F, Pan J W, Ponder S L, Vaughan J T, Twieg D B, Pohost G M
Department of Medicine, University of Alabama at Birmingham 35294.
Magn Reson Med. 1994 Nov;32(5):565-71. doi: 10.1002/mrm.1910320504.
Using a 4.1T whole body system, we have acquired 1H spectroscopic imaging (SI) data of N-acetyl (NA) compounds, creatine (CR), and choline (CH) with nominal voxel sizes of 0.5 cc (1.15 cc after filtering). We have used the SI data to estimate differences in cerebral metabolites of human gray and white matter. To evaluate the origin of an increased CR/NA and CH/NA ratios in gray matter relative to white matter, we measured the T1 and T2 of CR, NA, and CH in gray and white matter using moderate resolution SI imaging. In white matter the T2s of NA, CR, and CH were 233 +/- 27, 141 +/- 18, and 167 +/- 20 ms, respectively, and 227 +/- 27, 140 +/- 16, and 189 +/- 25 ms in gray matter. The T1 values for NA, CR, and CH were 1267 +/- 141, 1487 +/- 146, and 1111 +/- 136 ms in gray matter and 1260 +/- 154, 1429 +/- 233, and 1074 +/- 146 ms in white matter. After correcting for T1 and T2 losses, creatine content was significantly lower in white matter than gray (P < 0.01, t-test), with a white/gray content ratio of 0.8, in agreement with biopsy and in vivo measurements at 1.5 and 2.0T.
我们使用4.1T全身系统，获取了N-乙酰（NA）化合物、肌酸（CR）和胆碱（CH）的1H波谱成像（SI）数据，标称体素大小为0.5立方厘米（滤波后为1.15立方厘米）。我们利用SI数据估计人类灰质和白质中脑代谢物的差异。为了评估灰质相对于白质中CR/NA和CH/NA比值升高的来源，我们使用中等分辨率SI成像测量了灰质和白质中CR、NA和CH的T1和T2。在白质中，NA、CR和CH的T2分别为233±27、141±18和167±20毫秒，在灰质中分别为227±27、140±16和189±25毫秒。灰质中NA、CR和CH的T1值分别为1267±141、1487±146和1111±136毫秒，白质中分别为1260±154、1429±233和1074±146毫秒。校正T1和T2损失后，白质中的肌酸含量显著低于灰质（P<0.01，t检验），白/灰含量比为0.8，这与活检以及1.5T和2.0T的体内测量结果一致。
