Differences in the Brain Cortical Thickness and Area of Different Lobes Between Fetuses with Intrauterine Growth Restriction and Controls Based on 3-Tesla Magnetic Resonance Imaging (MRI)

Abstract

Background: Intrauterine growth restriction (IUGR) is a major factor in long-term perinatal morbidity and is associated with abnormal fetal brain development; however, its pattern of brain involvement remains unknown. Objectives: This study aimed to investigate the effect of IUGR on the brain parenchyma. Methods: Forty-two women with IUGR pregnancy and 28 women with normally grown fetuses at 28 - 38 weeks of pregnancy underwent 3-tesla magnetic resonance imaging (MRI). Cortical thickness was assessed in four regions and corrected by the biparietal diameter/2. Also, the whole brain surface area (WBA) was measured, and the areas of six brain regions were calculated and corrected by WBA. Results: In the IUGR group, the cortical thickness in the insula and temporal lobe was significantly thinner than the control group (0.034 vs. 0.043 and 0.036 vs. 0.047, respectively; P < 0.05); these fetuses also showed significantly reduced WBA (P = 0.028). The corrected brain areas were not significantly different between the groups, except for the corrected areas of the cerebellum and the hippocampus, which increased in the IUGR group as compared to the control group (0.147 vs. 0.130 and 0.017 vs. 0.0125, respectively; P < 0.05). Conclusions: In the IUGR fetuses, significantly thinner insular cortex and temporal lobe cortex and smaller WBA were found compared to the control group. Among different brain regions, the cerebellum and the hippocampus were less affected by growth restriction in the antenatal period.

Comparing the Diagnostic Yield of Antenatal Fetal Ultrasound, Neurosonography, and MRI for Detecting CNS Anomalies: A Prospective Study

“…For decades, prenatal US has been continually considered the preferred method of assessing fetal brain morphology, as it offers a real-time examination, is noninvasive and easy to operate, is reproducible, inexpensive, and provides a high diagnostic yield at an appropriate precision (10). Despite all of the mentioned advantages, ultrasound imaging is operator dependent and of limited value in maternal obesity, adverse fetal position, and multiple pregnancies, and also generates images with relatively low contrast resolution of soft tissues (11). Additionally, acoustic shadows from the fetal calvarium (especially in later pregnancies) confer imaging artifacts that suppress the quality of images, sometimes to such an extent that even gross anatomic features cannot be visualized (12).…”

“…In a recent meta-analysis, standard US was concluded to be an adequate screening tool in antenatal assessments, although MRI was recommended for those with abnormal brains on US as it may add diagnostic information in nearly 22.2% of cases (18). MRI depicts morphological features of the developing fetal brain in detail and at great spatial and contrast resolution, visualizing early and subtle structural deficits with acceptable accuracy (11,19). Besides, MRI delineates the cerebral and cerebellar cortex and achieves a satisfactory visualization of subarachnoid space as MR images are not disturbed by the calvarium (20).…”