Acoustic radiation force impulse elastography of the eyes of brachycephalic dogs

ABSTRACT Eyes from brachycephalic dogs were studied by acoustic radiation force impulse (ARFI) elastography to establish quantitative and qualitative reference values related to the shape and rigidity of some ocular structures. Eighty-four eyes from 42 adult brachycephalic dogs were included in this study. Animals were subjected to physical, laboratory, and ophthalmic examinations. Following confirmation of good health, the dogs were subjected to ultrasonography and ARFI elastography, emphasizing the optic nerve, ciliary body, and lens. On qualitative elastography, homogeneous characteristics were observed on the ciliary body and optic nerve. Aqueous and vitreous humors were visualized as mosaic-like images. Quantitative elastography showed the mean optic nerve shear wave velocity (SWV) was 1.01±0.27m/s, temporal ciliary body was 0.91±0.24m/s, and nasal ciliary body was 0.91±0.3m/s. The SWV of the lens values were out of range, this value was not detectable by this software. Elastography has proved to be a non-invasive procedure and feasible in dogs. The establishmentof the parameters of degree of rigidity of ocular structures will serve as a baseline for animals with eye disorders. Results may be extrapolated to primary research on the applicability of ARFI in the evaluation of ocular bulb in humans.

摘要 本研究通过声辐射力脉冲（acoustic radiation force impulse, ARFI）弹性成像技术对短头颅犬的眼部进行研究，旨在建立与部分眼部结构形态及硬度相关的定量与定性参考值。本研究共纳入42只成年短头颅犬的84只眼部样本。所有受试犬均接受体格检查、实验室检查及眼科检查。在确认其健康状况良好后，对受试犬进行超声检查及ARFI弹性成像检查，重点关注视神经、睫状体与晶状体。定性弹性成像结果显示，睫状体与视神经呈现均一特征；房水与玻璃体则呈现出马赛克样影像。定量弹性成像结果显示，视神经的平均剪切波速度（shear wave velocity, SWV）为1.01±0.27m/s，颞侧睫状体为0.91±0.24m/s，鼻侧睫状体为0.91±0.3m/s。而晶状体的SWV值超出检测量程，该软件无法检测到此数值。研究证实，弹性成像是一种无创且适用于犬类的检查手段。眼部结构硬度参数的建立，将为眼部疾病动物的相关研究提供基线参考。本研究结果可外推至ARFI技术在人类眼球评估领域的应用相关基础研究。