Girard Nadine, Chaumoitre Kathia, Confort-Gouny Sylvianne, Viola Angele, Levrier Olivier
Service de Neuroradiologie Diagnostique et Interventionnelle, Hôpital de la Timone, Marseille, France.
Curr Opin Obstet Gynecol. 2006 Apr;18(2):164-76. doi: 10.1097/01.gco.0000193002.58158.07.
Magnetic resonance imaging is playing an increasingly prominent role in depicting brain maturation, especially gyral formation that follows a temporospatial pattern, and in detecting developmental abnormalities of the cortex and other brain sectors. Knowledge of the technical advantages and limitations of in-utero magnetic resonance imaging techniques, relative to those of the postnatal period, is essential to optimize magnetic resonance sequences for early diagnosis. This includes an understanding of the changes in both brain anatomy and magnetic resonance signals that occur with an increase in gestational age.
Magnetic resonance imaging has evolved has an important adjunct in the diagnosis of brain malformations, particularly in the late-second or third trimester. Noxious conditions elicit more of a chronic rather than acute response in the fetal brain, which differs from that observed postnatally. Clinical applications of proton magnetic resonance spectroscopy may help elucidate fetal brain maturation and its abnormalities from a metabolic point of view.
Indications for fetal brain magnetic resonance imaging have increased because of improvements in magnetic resonance techniques and the ability to detect subtle changes within the cerebral parenchyma, especially in fetuses at increased risk of brain damage.
磁共振成像在描绘脑成熟过程中发挥着越来越重要的作用，尤其是遵循时空模式的脑回形成，以及在检测皮质和其他脑区的发育异常方面。了解相对于出生后时期，宫内磁共振成像技术的技术优势和局限性，对于优化磁共振序列以进行早期诊断至关重要。这包括了解随着胎龄增加而发生的脑解剖结构和磁共振信号的变化。
磁共振成像已发展成为诊断脑畸形的重要辅助手段，尤其是在孕中期晚期或孕晚期。有害状况在胎儿脑中引发的更多是慢性而非急性反应，这与出生后观察到的情况不同。质子磁共振波谱的临床应用可能有助于从代谢角度阐明胎儿脑成熟及其异常情况。
由于磁共振技术的改进以及检测脑实质内细微变化的能力，胎儿脑磁共振成像的适应证有所增加，尤其是对于有脑损伤风险增加的胎儿。
