摘要
用质子磁共振光谱法(1H-MRS)比较了小于胎龄儿(SGA)与接近正常胎龄儿(AGA)的大脑发育及代谢状况。据推测,由于胎盘机能不全所导致宫内生长迟缓与脑代谢改变有关,而且在幼儿2岁时通常出现大脑发育不良状况,我们对此假设进行了验证。26例AGA及14例SGA(出生前体重【2.3 kg)被纳入本研究,所有产儿均经超声检查没有明显异常。在孕32-41周时,给予1H-MRS及磁共振检查。用1H-MRS方法主要检查了基底节及脑室周的白质。分别对AGA组及SGA组的乙酰天冬氨酸/胆碱(NAA/Cho)、乳酸盐/胆碱、肌醇/胆碱(ml/Cho)以及谷氨酸-谷氨酰胺-γ-氨基丁酸/胆碱(Glx/Cho)进行比较。在检查者2岁时用Grif- fith发育指数(DQ)进行评分。应用Griffith发育指数(AGA,104±10;SGA,99±9)和用磁共振检查所得到的大脑发育状况对两组进行比较,结果显示AGA和SGA 组没有显著差别。同样,NAA/Cho、ml/Cho、Glx/Cho的比值在两组间也没有差异。从第32周开始到第41周, NAA/Cho比值增加,而ml/Cho比值在两组中均下降。AGA组与SGA组相比较,在脑代谢、大脑发育及DQ 评分方面均没有差异。
In the present study, we compared brain development and metabolism of small-for-gestational-age (SGA) and appro-priate-for-gestational-age (AGA) infants using proton magnetic resonance spectroscopy (1H-MRS) . We tested the hypothesis that intrauterine growth retardation caused by placental insuffi-ciency is associated with changes in cerebral metabolism and is followed by an adverse neurodevel-opmental outcome at the age of 2 y. Twenty-six AGA and 14 SGA (birth weight < P 2. 3) - preterin infants with no major ultrasound abnormalities were enrolled prospectively. At 32 and 41 wk postmenstrual age, 1H-MRS and magnetic resonance imaging were performed. For 1H-MRS, a volume of interest was placed in the basal ganglia and in the periventricular white matter. Using echo times of 31 and 144 ms N-acetylaspartate/choline (NAA/Cho), lactate/ Cho, myo-inositol/Cho (ml/Cho), and glutamate-glutam-ine-γ-aminobutyric acid/Cho (Glx/Cho) ratios were compared between AGA and SGA groups. Griffiths' developmental quotient (DQ) - values were assessed at 24 mo corrected age. Griffiths' DQ (AGA, 104 ± 10; SGA, 99 ± 9) and brain development assessed using magnetic resonance imaging showed no significant differences between both AGA and SGA groups, and NAA/Cho, Lac/Cho, ml/Cho, and Glx/Cho ratios were not significantly different between the groups. NAA/Cho ratios increased from 32 to 41 wk, whereas ml/Cho ratios decreased in both groups. No differences in cerebral metabolism, brain development, and DQ values between AGA and severely SGA infants could be demonstrated.
