兔眼内铁磁性异物MRI诊断研究  

An study of intraocular ferromagnetic foreign bodies on MRI in rabbits

作　　者：程敬亮[1,2,3] 姜曦[1,2,3] 游浩凌 齐云秋 任翠萍[1,2,3] 李天晓 

机构地区：[1]河南医科大学第一附属医院放射科 [2]河南医科大学第一附属医院眼科 [3]河北省张家口市第四医院眼科

出　　处：《河南医科大学学报》1998年第2期28-31,共4页Journal of Henan Medical University

基　　金：河南省科技攻关项目

摘　　要：为探讨眼内铁磁性异物ＭＲＩ时的移动性，对９枚铁屑（０．２ｍｍ×０．２ｍｍ×０．１ｍｍ～４ｍｍ×３ｍｍ×３ｍｍ）进行了体外实验，对１０枚铁屑（０．２ｍｍ×０．１ｍｍ×０．１ｍｍ～３．５ｍｍ×３ｍｍ×３ｍｍ）进行了体内实验。体外实验将铁屑放入盛有兔眼玻璃体的透明玻璃瓶中，体内实验将异物置入５只兔的１０眼玻璃体内。ＭＲＩ使用ＳｉｅｍｅｎｓＩｍｐａｃｔ１．０ＴＭＲ机。体内实验ＭＲＩ前后经检眼镜和ＣＴ观察异物移动情况，并拍摄Ｘ线平片。结果：体外实验发现仅１枚最小铁屑（０．２ｍｍ×０．２ｍｍ×０．１ｍｍ）未见移动，其他８枚均见异物向主磁场方向移动。体内实验３枚小于０．３ｍｍ×０．３ｍｍ×０．２ｍｍ铁屑未见移动，大于０．４ｍｍ×０．３ｍｍ×０．２ｍｍ的７枚铁屑均见移动，但并未导致视网膜损伤。ＭＲＩ均发现铁异物周围有大于异物数十倍的金属伪迹；小于０．４ｍｍ×０．３ｍｍ×０．２ｍｍ的４枚铁屑Ｘ线平片均未显示。结果提示：眼内铁磁性异物移动性与异物大小有关，异物愈大愈易移动；Ｘ线平片不能显示的眼内铁异物在１．お? In order to evaluate the movement of intraocular ferromagnetic foreign bodies during MRI examination,9 iron particles (size from 0.2 mm×0.2 mm×0.1 mm to 4 mm×3 mm×3 mm) were tested in vivo and 10(size from 0.2 mm×0.1 mm×0.1 mm to 3.5 mm×3 mm×3 mm)in vitro.For the in vitro study,iron particles were implanted into the corpus vitreum of 10 eyes of 5 rabbits,and iron particles were only dropped into a small glass bottle containing the corpus vitreum from the rabbit eyes in vivo.Both were tested under a Siemens Impact 1.0 T MRI system.The movement of the iron particles before and after the MRI study in vitro was evaluated by ophthalmoscope,CT and Xray plain film as well.The in vivo study showed that 8 of 9 iron particles moved toward the direction of the main magnetic field,while only one tiny particle (0.2 mm×0.2 mm×0.1 mm)had no movement.In the in vitro study,7 iron particles which were larger than 0.4 mm×0.3 mm×0.2 mm showed some movements,but 3 of those which were less than 0.3 mm×0.3 mm×0.2 mm showed no movement,neither of them led to damage of the relina.There was always a huge artifact shown on MRI more than 10 times larger than the iron particle itself. Four iron particles which were less than 0.4 mm×0.3 mm×0.2 mm were not identified by roentgenograms.The results revealed that movement of intraocular ferromagnetic foreign bodies was related to its volume,and the larger the volume the more the movement.Those iron particles which were not exhibited by roentgenograms could be safely examined under a 1.0 T MRI system.

关 键 词：眼异物 磁共振成像 铁磁性异物 

分 类 号：R779.140.4[医药卫生—眼科] R445.2[医药卫生—临床医学]