磁共振成像RS-EPI序列在眼眶肿瘤及肿瘤样病变中的诊断价值

Value of diffusion-weighted magnetic resonance imaging using readout-segmented echoplanar imaging sequence in the diagnosis of orbit tumors and tumorlike lesions

目的研究磁共振成像分段读出平面回波成像(RS-EPI)序列在诊断眼眶肿瘤及肿瘤样病变中的应用价值。方法本研究为回顾性研究,以2016年12月~2018年12月在我院诊断并治疗的眼眶肿瘤及肿瘤样病变患者60例作为研究对象,所有患者均采取3T磁共振扫描仪(MAGNETOM Trio Tim)进行扫描,分别比较RS-EPI以及单次激发平面回波成像(SS-EPI)序列图像质量定性评分、图像质量定量评分的差异。分析RS-EPI序列及SS-EPI序列对于眼眶肿瘤及肿瘤样病变诊断效能之间的差异。结果两种方法对观察者组患者脂肪抑制情况之间的差异无统计学意义(P>0.001),RS-EPI序列诊断方法对于观察者组患者的正常解剖结构的显示能力、伪影情况以及图像综合质量评分高于SS-EPI序列(P<0.001);两种方法对观察者组患者玻璃体表观扩散系数(ADC)、脑干ADC脂的差异无统计学意义(P>0.05),RS-EPI序列诊断方法对于观察者组患者眼球前后、眼球左右的几何变形情况及信噪比低于SS-EPI序列(P<0.001);RS-EPI序列对于眼眶肿瘤及肿瘤样病变的诊断敏感度高于SS-EPI序列(P<0.05);ROC曲线显示,RS-EPI序列对于眼眶肿瘤及肿瘤样病变的曲线下面积高于SS-EPI序列(P<0.001)。结论磁共振成像RS-EPI序列可有效提升眼眶肿瘤及肿瘤样病变的图像质量以及诊断敏感度。

Objective To evaluate the value of diffusion-weighted MRI using readout-segmented echo-planar imaging(RS-EPI)sequence in the diagnosis of orbit tumors and tumorlike lesions.Methods A retrospective study was performed on 60 patients with orbital tumors or tumorlike lesions in our hospital from December 2016 to December 2018.The patients were imaged on a 3T MRI scanner(MAGNETOM Trio Tim).The RS-EPI and single-shot echo-planar imaging(SS-EPI)sequences were compared in terms of image quality.The diagnostic efficacy between RS-EPI sequence and SS-EPI sequence for orbital tumors and tumorlike lesions were compared.Results Fat suppression in the RS-EPI sequence showed no statistical difference to that in the SS-EPI sequence(P>0.05),while RS-EPI sequence was was superior to SS-EPI sequence in terms of normal anatomical structure display,ghosting artifact,overall image quality(P<0.001).The apparent diffusion coefficient(ADC)values of vitreous body and brainstem yielded no statistical difference between two methods(P>0.05).The geometric distortion ratio in both anterior-posterior and right-left direction,as well as signal-to-noise ratio of RS-EPI sequence were all lower than those of SS-EPI sequence(P<0.001).The diagnostic sensitivity of RS-EPI sequence for orbital tumors and tumorlike lesions was significantly higher than that of SS-EPI sequence(P<0.05).ROC curve denoted that the area under the curve of RS-EPI sequence in the diagnosis of orbital tumors and tumorlike lesions was significantly larger than that of SS-EPI sequence(P<0.001).Conclusion MRI using RS-EPI sequence can effectively improve the image quality and diagnostic sensitivity of orbital tumors and tumorlike lesions.