Hüppi P S, Barnes P D
Joint Program in Neonatology, Harvard Medical School, Boston, Massachusetts, USA.
Clin Perinatol. 1997 Sep;24(3):693-723.
MR imaging provides unequaled sensitivity as compared with US or CT scanning for evaluating developmental changes and pathologic processes in the newborn brain. Myelination can be assessed qualitatively and quantitatively using newer 3D-MR imaging methods. MR imaging provides a much clearer delineation of many developmental disorders, including anomalies of migration and organization, as well as a variety of metabolic disorders and congenital infections. Neonatal intracranial hemorrhage is detected in all its locations by MR imaging. The timing of the hemorrhage is a unique feature of MR imaging. Venous thrombosis also can be identified by MR imaging and confirmed with MR angiography. HIE is the major cause of potentially preventable or reversible brain injury that results in considerable long-term neurologic morbidity. Early detection is crucial for interventions aimed at preventing or reversing ongoing injury. DWI can show early changes at the cellular level that are not detectable by any other imaging modality. MR spectroscopy has further opened the possibility of studying the metabolic mechanisms that define the pathophysiologic events taking place in neonatal brain injury. Both 31P-MR spectroscopy, as a marker of the acute changes in energy metabolism, and 1H-MR spectroscopy, with the measurement of lactate and the excitotoxic aminoacids glutamate and glutamine, have enabled us to study the early and late effects of insults to the newborn brain in a noninvasive fashion. Studies performed to determine the predictive value of MR spectroscopy for later neurodevelopmental outcome after HIE have shown promising results but need further evaluation on larger patient samples. The potential use of these methods in the evaluation of early neuroprotective treatment regimens in the newborn remains to be determined.
与超声或CT扫描相比，磁共振成像（MR成像）在评估新生儿脑发育变化和病理过程方面具有无与伦比的敏感性。使用更新的三维MR成像方法可以对髓鞘形成进行定性和定量评估。MR成像能更清晰地描绘许多发育障碍，包括迁移和组织异常，以及各种代谢紊乱和先天性感染。MR成像可检测到新生儿颅内出血的所有部位。出血时间是MR成像的一个独特特征。静脉血栓形成也可通过MR成像识别，并通过磁共振血管造影证实。缺氧缺血性脑病（HIE）是潜在可预防或可逆性脑损伤的主要原因，会导致相当严重的长期神经功能障碍。早期检测对于旨在预防或逆转正在发生的损伤的干预措施至关重要。扩散加权成像（DWI）可以显示细胞水平的早期变化，这是其他任何成像方式都无法检测到的。磁共振波谱学进一步开启了研究定义新生儿脑损伤中病理生理事件的代谢机制的可能性。作为能量代谢急性变化标志物的磷-31磁共振波谱学（31P-MR波谱学）以及用于测量乳酸、兴奋性毒性氨基酸谷氨酸和谷氨酰胺的氢-1磁共振波谱学（1H-MR波谱学），都使我们能够以非侵入性方式研究新生儿脑损伤的早期和晚期影响。为确定MR波谱学对HIE后后期神经发育结局的预测价值而进行的研究已显示出有希望的结果，但需要对更大的患者样本进行进一步评估。这些方法在评估新生儿早期神经保护治疗方案中的潜在用途仍有待确定。
