兔眼玻璃体内木质异物的磁敏感加权成像研究

Susceptibility Weighted Imaging Study of Wooden Foreign Body in Vitreous Body of Experimental Rabbits

目的探讨兔眼玻璃体内木质异物的磁敏感加权成像(SWI)的特点。方法取实验兔48只,右眼玻璃体内分别植入1枚直径0.2 mm、长2 mm的木质异物,以不植入异物的左眼为对照,于术后2小时行SWI序列检查。结果对于48枚兔眼玻璃体内木质异物,SWI序列检出率为100%,检出的异物呈点状或条状,在幅值图、最小信号强度投影(m IP)图及SWI图上呈低信号,相位图上31枚呈低信号,13枚呈高信号。SWI序列检出异物直径较异物实际直径大。结论兔眼玻璃体内木质异物在SWI序列上具有特征性,异物在SWI上具有放大效应,SWI序列可用于兔眼玻璃体内微小木质异物的检出和诊断。

Objective To investigate susceptibility weighted imaging （SWI） features of wooden foreign body in vitreous body of experimental rabbits. Methods A total of 48 rabbits were used for this study. One small wooden grain, which was 0.2 mm in diameter and 2 mm in length, was implanted into the right vitreous body in each rabbit. The left eye was used as control. SWI sequence scanning was performed 2 hours after the implantation. Results The 48 wooden foreign bodies in the rabbit vitreous body were all detected by SWI sequence, the detection rate was 100%. The wooden foreign bodies were dot or strip in shape. On the magnitude map, minimum intensity projection （mIP） image and SWI, 31 foreign bodies presented as hypointense signal and 13 foreign bodies presented as hyperintense signal. The diameter of the foreign body measured on SWI was larger than its real diameter. Conclusion Wooden foreign body in rabbit vitreous body has characteristics on SWI image, and SWI has amplification effect on foreign body. SWI sequences can be used for the detec- tion and diagnosis of tiny wooden foreign body in rabbit vitreous body.