Priego G, Barrowman N J, Hurteau-Miller J, Miller E
From the Department of Medical Imaging (G.P., J.H.-M., E.M.).
Dr Priego is now with Department of Medical Imaging, Queen's Hospital, London, UK.
AJNR Am J Neuroradiol. 2017 Aug;38(8):1636-1642. doi: 10.3174/ajnr.A5251. Epub 2017 Jun 15.
Stronger magnetic fields have the potential to improve fetal image resolution. Our objective was to detect whether there was better anatomic resolution of brain structures in fetuses imaged with a 3T magnet compared with a 1.5T magnet.
Multiple cerebral and facial anatomic structures were retrospectively assessed in 28 fetal MR imaging scans with normal findings (12 at 3T and 16 at 1.5T) with a 0-3 grading score. Fetuses were assessed during the second trimesters (gestational age, 20-24 weeks). The association between the quality ratings and magnetic field strengths (1.5T versus 3T) was evaluated by a linear mixed-effects model. A quantitative assessment of the signal intensity was also performed in the different layers of the developing brain. Comparative log-ratios were calculated across the different layers of the fetal brain.
There was a statistically significant interaction between location and magnetic field strength ( < .001). The cerebral structures of the cerebellum, pons, venous system, semicircular canal, and cochlea showed statistically significant higher values on the 3T magnet. Similarly, statistical significance was also obtained on the quantitative assessment of the multilayer appearance of the brain; the 3T magnet had a median factor of 8.38 higher than the 1.5T magnet (95% CI, 4.73-14.82). Other anatomic structures assessed in the supratentorial compartment of the brain showed higher values on the 3T magnet with no statistical significance.
Both magnets depict cerebral and facial normal anatomic structures; however, our data indicates better anatomic detail on the 3T than on the 1.5T magnet.
更强的磁场有可能提高胎儿图像分辨率。我们的目的是检测与1.5T磁体相比，使用3T磁体成像的胎儿脑结构解剖分辨率是否更高。
回顾性评估了28例胎儿磁共振成像扫描（12例为3T，16例为1.5T）中多个脑和面部解剖结构，采用0 - 3分级评分。在孕中期（孕周20 - 24周）对胎儿进行评估。通过线性混合效应模型评估质量评级与磁场强度（1.5T与3T）之间的关联。还对发育中大脑的不同层进行了信号强度的定量评估。计算了胎儿脑不同层之间的比较对数比。
位置与磁场强度之间存在统计学显著的交互作用（P <.001）。小脑、脑桥、静脉系统、半规管和耳蜗的脑结构在3T磁体上显示出统计学显著更高的值。同样，在对大脑多层外观的定量评估中也获得了统计学显著性；3T磁体的中位数因子比1.5T磁体高8.38（95%可信区间，4.73 - 14.82）。在大脑幕上间隙评估的其他解剖结构在3T磁体上显示出更高的值，但无统计学显著性。
两种磁体均能描绘脑和面部的正常解剖结构；然而，我们的数据表明3T磁体上的解剖细节比1.5T磁体更好。
