Department of Biomedical Engineering, Cornell University, Ithaca, New York 14853-7501, USA.
Dev Dyn. 2011 Aug;240(8):1949-57. doi: 10.1002/dvdy.22694.
Many clinically relevant congenital malformations arise during mid to late embryonic stages. This period is challenging to image quantitatively in live embryos, necessitating the use of multiple specimens with increased experimental variability. Here we establish X-ray and blood-pool computed tomography (CT) contrast agent toxicity and teratogenesis thresholds for 3D Micro-CT imaging of live avian embryos. Day 4 chick embryos micro-injected with Visipaque™ (VP) developed for an additional 6 days without defect. X-ray radiation up to 798 mGy was nontoxic. Peak average contrast of 1,060 HU occurred within 1 hr of imaging at 50 μm resolution. VP-enhanced contrast persisted past 24 hr with delayed accumulation in the allantois. Regional volumes of VP-injected embryos were statistically identical to those of fixed embryos perfused with osmium tetroxide. We further quantified longitudinal volumetric morphogenesis of the allantois over 30 hr. These results demonstrate the safety and efficacy of contrast enhanced quantitative micro-CT imaging for live embryos.
许多具有临床相关性的先天畸形是在胚胎中期到晚期发生的。这一时期很难对活体胚胎进行定量成像，因此需要使用多个样本，这会增加实验的变异性。在这里，我们为活体禽类胚胎的 3D 微 CT 成像确定了 X 射线和血池 CT 造影剂的毒性和致畸阈值。在第 4 天鸡胚中注射 Visipaque（VP）后，鸡胚又发育了 6 天，没有出现缺陷。X 射线辐射高达 798 毫戈瑞是无毒的。在 50μm 分辨率下，1 小时内成像时达到 1060 个 HU 的峰值平均对比度。VP 增强的对比度在 24 小时后仍能持续存在，并且在卵黄囊中会延迟积累。VP 注射胚胎的区域体积与用四氧化锇灌注固定的胚胎体积统计学上相同。我们进一步定量分析了卵黄囊中 30 小时的纵向体积形态发生。这些结果表明，对比增强定量微 CT 成像对活体胚胎是安全有效的。
