兔眼玻璃体内微小石质异物的磁共振成像研究

An investigation of tiny stony foreign body in rabbit vitreous body with MRI

目的:探讨磁敏感加权成像(SWI)和常规MRI序列对兔眼玻璃体内微小石质异物的诊断价值。方法:选取试验动物40只分成4组,每组10只,将0.2 mm的石块、瓷器、煤块和石墨各10枚分别植入右眼玻璃体内,以左眼作为对照,均于手术后2 h内行MRI检查,磁共振检查序列包括T_1WI、T_2WI、PDWI、3D-DESS和SWI。结果 :40枚石质异物中,常规T_1WI、T_2WI、PDWI、3D-DESS序列对4种石质异物的检出率分别为75%、83%、68%、93%;SWI序列Mag图、Pha图、mIP图、SWI图检出率分别为88%、88%、78%、88%。常规序列中3D-DESS序列的放大率最高,T_2WI序列检出异物直径接近于实际直径,SWI序列中mIP图的放大率最高。结论:3D-DESS序列和SWI序列是诊断眼球玻璃体内微小石质异物敏感序列,其对异物的放大效应有利于异物的检出,是常规MRI诊断的重要补充手段。

Objective： To investigate the MRI features of stony foreign body in rabbit vitreous body by susceptibility weighted imaging （SWI） and conventional sequences. Methods： Forty healthy rabbits were involved in this study. Experimental group were ten rabbits. Selected stones, porcelain, coal, graphite four stone material as foreign body （maximum diameter were 0.2 mm） that were randomly and respectively implanted into 40 right rabbit＇s vitreous body. Take the left rabbits vitreous body implanted as reference, all cases were underwent T1WI, T2WI, PDWI, 3D-DESS and SWI sequences examination in 2 hours. Highest magnification was 3D-DESS sequence of conventional sequence, the diameter of foreign bodies on T2WI sequence was closed to the actual diameter, highest magnification was mlP figure of SWI sequence. Results： All of 40 stony foreign bodies, the diagnosis rate of T1WI, T2WI, PDWI, 3D-DES sequences was 75%, 83%, 68%, 93%. The diagnosis rate of Mag, Pha, mlP, SWI figures was 88%, 88%, 78%, 88%. Conclusion： 3D-DESS and SWI were sensitive sequences for detecting tiny stony foreign body in vitreous bodies, for the amplification effect that could be used for the detection of foreign bodies as a complementary method for convention MRI.