Date Published: April 4, 2019
Publisher: Public Library of Science
Author(s): Zhonghe Zhang, Xiangtao Lin, Qiaowen Yu, Gaojun Teng, Fengchao Zang, Ximing Wang, Shuwei Liu, Zhongyu Hou, Yong Fan.
Few investigators have analyzed fetal ocular growth with Magnetic Resonance Imaging (MRI) of high magnetic strength. Our purpose is to obtain normative biometrics for fetal ocular development in the second trimester of pregnancy. Sixty specimens with a gestational age (GA) of 12–23 weeks were scanned using a 7.0 T MRI scanner. The linear interocular and binocular distances (IOD and BOD, respectively), globe diameter (GD) and lens diameter (LD) were measured on the transverse section of the largest diameter of the eyeballs. The three dimensional (3D) visualization model of the eyeball was reconstructed with Amira software. Then, the globe and lens volumes (GV and LV, respectively) were obtained. All the measurements were plotted as a function of GA. The fetal ocular structures in the second trimester of pregnancy could be clearly delineated on 7.0 T postmortem MRI images. All the linear measurements logarithmically increased with GA, while, the volumetric measurements linearly increased with GA. Postmortem MRI of high magnetic strength can clearly document fetal ocular growth in the second trimester of pregnancy. These quantitative data may be a valuable reference for the assessment of normal fetal eyeball development in clinical settings and may be considered a supplement to anatomical investigations.
The morphology of each organ changes gradually during the normal fetal developmental process in vivo. Biometric data are an important diagnostic reference in the assessment of fetal health for all imaging examinations, and large datasets from previous research can be found in the literature [1–6]. Although eyeball and orbital imaging examinations are not routinely performed in obstetrical ultrasound (US) during the early stages of pregnancy, it is a reasonable and essential expectation to perform them for a detailed anatomical scan [7, 8]. A previous study discovered that quite obvious ocular pathologies have been missed on US in clinical settings, particularly if they are bilateral and symmetrical . Additionally, the diagnoses are not convincing and may even be completely altered if a coexisting ocular pathology is discovered . Therefore, assessment of fetal ocular development has been routinely included in fetal Magnetic Resonance Imaging (MRI) or US examinations, and it is important to obtain precise quantitative measurements during the normal growth process.
Fetal ocular structures in the second trimester of pregnancy can be clearly document with 7.0 T postmortem MRI. The quantitative data presented here may be a valuable reference for the assessment of normal fetal eyeball development in clinical settings and as a supplement to anatomical investigations.