MR磁化传递对比成像观察新生儿轻度窒息

目的观察MR磁化传递对比(MTC)成像在轻度窒息新生儿中的应用价值。方法对15例轻度窒息新生儿(Apgar评分10分,病例组)及25名正常新生儿(对照组)采集脑常规T1WI、3D-T1WI和T1WI-MTC,计算脑磁化率(MTR),配准于标准新生儿脑模板后行统计分析。采用3dRegAna对病例组MTR与Apgar评分进行回归分析。结果相比对照组,病例组右颞极、左颞下回、左额上回、右缘上回、右眶额皮质、左额中叶、右额中回及左上额叶MTR显著降低;右梭状回、右顶叶下回、右枕中回、右颞中回、右颞下回、右颞上极、右楔叶、右角回、右舌回及右颞上回MTR显著增加。回归分析显示,病例组左中央后回、右颞下叶(前)、右额中回、右颞上极、左眶额皮质及右颞下叶(后)MTR与Apgar评分呈正相关,右壳核、右眶额皮质、左杏仁核、右颞下回、左舌回、右舌回、左颞中回、左枕中回、延髓及右梭状回呈负相关。组间MTR差异有统计学意义、且病例组MTR与Apgar评分呈正相关脑区为右额中叶、右颞极,呈负相关脑区则为右舌叶及右梭状回。结论 MR MTC成像能检出轻度窒息新生儿缺血缺氧脑区;缺血缺氧主要导致新生儿右侧脑损害。

MR magnetization transfer contrast imaging in observation on neonate mild asphyxia

Objective To observe the application value of MR magnetization transfer contrast (MTC) imaging in neonate mild asphyxia. Methods Acquisitions of conventional brain T1WI, 3D-T1WI and MTC-T1WI were performed, and magnetization transfer ratio (MTR) of brain was calculated and registered to the standard neonatal brain template for statistical analysis of 15 neonates with mild asphyxia (Apgar score<10, case group) and 25 normal neonates (control group). 3dRegAna was used to conduct the regression analysis of brain MTR and Apgar score in case group. Results Compared with control group, the brain regions with significantly decreased MTR in case group included right temporal pole, left inferior temporal gyrus, left superior frontal gyrus, right superior marginal gyrus, right orbitofrontal cortex, left middle frontal lobe, right middle frontal gyrus and left upper frontal lobe; while the areas with significant increased MTR included right fusiform gyrus, right inferior parietal gyrus, right middle occipital gyrus, right middle temporal gyrus, right inferior temporal gyrus, right superior temporal pole, right cuneiform lobe, right angular gyrus, right lingual gyrus and right superior temporal gyrus. Regression analysis showed that the brain regions with positive correlation between brain MTR and Apgar score in case group included left posterior central gyrus, right inferior temporal lobe (anterior), right middle frontal gyrus, right superior temporal pole, left orbitofrontal cortex and right inferior temporal lobe (posterior); while the negatively correlated brain regions included right putamen, right orbitofrontal cortex, left amygdala, right inferior temporal gyrus, left lingual gyrus, right lingual gyrus, left middle temporal gyrus, left middle occipital gyrus, medulla oblongata and right fusiform gyrus. The brain regions with MTR being significant different between groups and the positive correlation between MTR and Apgar score in case group were right middle frontal lobe and right temporal pole, and those with negative correlation including right lingual lobe and right fusiform gyrus. Conclusion MR MTC imaging technique could detect ischemic and hypoxic brain regions in neonates with mild asphyxia. Ischemia and hypoxia mainly leaded to right brain damage in neonates.