正常人视神经的MRI研究

MRI Measurement of the Optic Nerve in Normal Adults

目的 :评价正常成人脑外段颅神经的MRI表现 ,建立正常标准 .方法 :随机选择正常成人志愿者 10 0例 ,采用GE 1 5TMR/i超导型磁共振成像仪及相控阵头线圈 ,成像序列包括自旋回波T1加权成像(SET1WI)和自旋回波T2加权成像 (SET2WI) ;扫描方位以视神经 -眼平面 (NOP)为基准扫描 .分别测量两组视神经眼球后神经膨大段直径、眶内段视神经直径、长度 ,管内段视神经直径及该段视神经起始至同侧视交叉的长度 ,后者与眶内段视神经长度之和即代表颅外段视神经的长度 .结果 :正常人眼球后神经膨大段直径为 (4 2± 0 72 )mm ,眶内段直径为 (3 1± 0 6 1)mm ,长度为 (2 4 6± 2 6 9)mm ,管内段视神经直径为(3 2± 0 5 5 )mm ,至同侧视交叉的长度为 (18 7± 2 4 8)mm ,颅外段视神经的长度为 (43 3± 3 6 8)mm .结论 :MRI可以很好显示视神经的形态 ,是研究其解剖和疾病的有效检查手段 .

Objective: To evaluate the MRI features of optic nerve in normal adults and establish the normal standards of the optic nerve. Methods: 50 healthy adult volunteers were studied with GE 1.5T MR/I and phase array head coil. The sequences included T1-weighted imaging(T1WI) of spin echo and T2-weighted imaging(T2WI) of spin echo, based on the neuro-optic plan (NOP). All diameters and lengths of the optic parts such as the thick part behind eyeball, intraorbital part and intra-canal part. were measured on the MRI images. Results: To the nerves behind eyeball, intraobital part and intra-canal part,the diameters were (4.2±0.72)mm, (3.1±0.61)mm, (3.2±0.55)mm respectively; the lengths of intraorbital part and intra-canl part were (24.6±2.69)mm and (18.7±2.48)mm respectively, the total length was (43.3±3.68)mm. The 6 measurement results had no significant difference (P>0.05). Conclusion: MRI can show the normal optic nerve, which is a optimale imaging diagnostic method for the morphologic identification of the optic nerve and prevention from its lesion.