Schneider Jürgen E, Bamforth Simon D, Grieve Stuart M, Clarke Kieran, Bhattacharya Shoumo, Neubauer Stefan
Department of Cardiovascular Medicine, John Radcliffe Hospital, University of Oxford, Headley Way, Oxford, OX3 9DU UK.
MAGMA. 2003 Feb;16(1):43-51. doi: 10.1007/s10334-003-0002-z.
Embryonic development in normal and genetically modified mice is commonly analysed by histological sectioning. This procedure is time-consuming, prone to artefact, and results in the loss of three-dimensional (3D) information. Magnetic resonance imaging (MRI) of embryos has the potential of noninvasively acquiring a complete 3D data set. Published methods have used spin-echo techniques with inherently high signal-to-noise ratio (SNR); however, they required either perfusion of the embryo with a contrast agent, or prolonged acquisition times to improve contrast and resolution. Here, we show that a standard preparation (i.e. paraformaldehyde fixation) of 15.5 days post-coitum embryos followed by MRI using a fast gradient-echo sequence with T(1)-weighting achieves high resolution and high throughput for investigating mouse embryonic anatomy. 3D data sets were acquired in overnight experiments (<9 h) with an experimental resolution of approximately 25 microm(3). This spatial resolution is twofold higher than the values reported previously for comparable paraformaldehyde-fixed embryos, and it was obtained in less than a quarter of the time with sufficient SNR. Our approach combines speed, high resolution and contrast with a simple preparation technique and minimal operator time (<1 h). It allows rapid routine 3D characterisation of normal and abnormal mouse embryonic anatomy.
正常和转基因小鼠的胚胎发育通常通过组织切片进行分析。该过程耗时、容易产生假象，并且会导致三维（3D）信息的丢失。胚胎的磁共振成像（MRI）具有无创获取完整3D数据集的潜力。已发表的方法使用具有固有高信噪比（SNR）的自旋回波技术；然而，它们要么需要用造影剂灌注胚胎，要么需要延长采集时间以提高对比度和分辨率。在这里，我们表明，对妊娠15.5天的胚胎进行标准制备（即多聚甲醛固定），然后使用具有T(1)加权的快速梯度回波序列进行MRI，可以实现高分辨率和高通量，用于研究小鼠胚胎解剖结构。在过夜实验（<9小时）中获取了3D数据集，实验分辨率约为25立方微米。这种空间分辨率比之前报道的类似多聚甲醛固定胚胎的值高出两倍，并且在不到四分之一的时间内获得，同时具有足够的SNR。我们的方法将速度、高分辨率和对比度与简单的制备技术以及最少的操作人员时间（<1小时）相结合。它允许对正常和异常小鼠胚胎解剖结构进行快速常规3D表征。
