Department of Ophthalmology, Rostock University Medical Center, Doberaner Straße 140, 18057, Rostock, Germany.
Institute of Diagnostic and Interventional Radiology, Rostock University Medical Center, Ernst-Heydemann-Str. 6, 18055, Rostock, Germany.
Mol Imaging Biol. 2019 Feb;21(1):78-85. doi: 10.1007/s11307-018-1208-9.
Ultrahigh-field MRI (UHF-MRI) with an in-plane spatial resolution of less than 100 μm is known as MR microscopy (MRM). MRM provides highly resolved anatomical images and allows quantitative assessment of different tissue types using diffusion-weighted imaging (DWI). The aim of the present study was to evaluate the feasibility of combined in vivo anatomical and quantitative assessment of the developing chicken eye in ovo.
Thirty-eight fertilized chicken eggs were examined at 7.1 T (ClinScan, Bruker Biospin, Germany) acquiring a dataset comprising T2-weighted anatomical images, DWI, and diffusion tensor imaging. To reduce motion artifacts, the eggs were moderately cooled before and during MR imaging. Two eggs were imaged daily for the entire developmental period, and 36 eggs were examined pairwise at only one time point of the embryonic period. Development of the eye was anatomically and quantitatively assessed.
From the D5 embryonic stage (116-124 h), MRM allowed differentiation between lens and vitreous body. The lens core and periphery were first identified at D9. DWI allowed quantification of lens maturation based on a significant decrease in apparent diffusion coefficient values and course of fractional anisotropy. Repeated moderate cooling had no influence on the development of the chicken embryo.
MRM allows in vivo assessment of embryonic development of the chicken eye in ovo without affecting normal development. The method provides anatomical information supplemented by quantitative evaluation of lens development using DWI. With increasing availability of ultrahigh-field MR systems, this technique may provide a noninvasive complementary tool in the field of experimental ophthalmology.
具有小于 100μm 面内空间分辨率的超高磁场磁共振成像（UHF-MRI）被称为磁共振显微镜（MRM）。MRM 提供高分辨率的解剖图像，并允许使用扩散加权成像（DWI）对不同的组织类型进行定量评估。本研究旨在评估在体评估鸡胚发育中鸡眼的解剖结构和定量评估的可行性。
在 7.1T（ClinScan，Bruker Biospin，德国）上检查了 38 个受精鸡蛋，采集了包括 T2 加权解剖图像、DWI 和扩散张量成像的数据集。为了减少运动伪影，在 MR 成像之前和期间适度冷却鸡蛋。两个鸡蛋在整个发育期间每天进行成像，36 个鸡蛋仅在胚胎期的一个时间点进行成对检查。对眼睛的发育进行了解剖学和定量评估。
从胚胎第 5 天（116-124 小时）开始，MRM 允许区分晶状体和玻璃体。在第 9 天首次识别晶状体核心和周围。DWI 允许根据明显扩散系数值的降低和各向异性分数的变化来定量评估晶状体成熟度。重复适度冷却对鸡胚的发育没有影响。
MRM 允许在不影响正常发育的情况下在体评估鸡胚的眼睛发育。该方法提供了解剖学信息，并通过 DWI 对晶状体发育进行定量评估。随着超高磁场磁共振系统的可用性增加，该技术可能为实验眼科领域提供一种非侵入性的补充工具。
