MRI低剂量增强3D-DIR-SPACE序列在腰骶丛神经成像中的应用价值

Application of low dose Enhanced 3D-DIR-SPACE sequence in lumbosacral plexus Imaging

目的探讨MRI低剂量增强三维双反转恢复可变翻转角快速自旋回波序列(3D-DIR-SPACE)在腰骶丛神经诊断中的应用价值。方法选取38例行腰骶丛增强MRI的患者并将其平分为两组,第一组:单倍剂量0.2 ml/kg注射2 min后行3D-STIR-SPACE扫描,第二组:低剂量0.1 ml/kg注射2 min后行3D-DIR-SPACE扫描,两组同时在增强前行3D-DIR/STIR-SPACE平扫。由2位诊断经验丰富的医师对两组增强图像进行评分,行统计学分析。在两组平扫图像同一层面测量神经、肌肉信号强度及背景信号强度标准差,计算CNR、SNR,行统计学分析。结果2位医师对两组增强图像的评分具有较好一致性(Kappa≥0.461),低剂量下3D-DIR-SPACE与建议剂量下3D-STIR-SPACE在增强后整体图像质量评分分别为4.71±0.41、4.78±0.45,差异无统计学意义(P>0.05)。3D-STIR/DIR-SPACE平扫的CNR、SNR,差异无统计学意义(P>0.05),相关性较好(P=0.07)。结论3D-DIR-SPACE序列联合低剂量增强扫描可在腰骶丛MRI中获得具有诊断效果的图像质量,具有一定的应用价值。

Objective To evaluate of the feasibility,image quality and application value of low dose enhanced three-dimensional double inversion time inversion recovery sampling perfection with application optimized contrasts using different flip angle evolution(3D-DIR-SPACE)sequence in lumbosacral plexus magnetic resonance imaging.Methods 38 patients with lumbosacral plexus enhanced MRI scan were equally divided into two groups.In the first group,3D-STIR-SPACE scan was performed 2 minutes after the injection of single dose of 0.2 ml/kg,the second group was 3D-DIR-SPACE scan after 2 minutes of low-dose 0.1 ml/kg injection,both groups were scanned with 3D-DIR/STIR-SPACE before enhancement.The CNR of nerves on 3D-DIR/STIR-SPACE plain scan was compared and statistically analyzed.The enhanced scores of 3D-DIR-SPACE and 3D-STIR-SPACE at low dose were compared and statistically analyzed.Two doctors with rich diagnosis experience scored the two groups of enhanced images and performed statistical analysis,measured the standard deviation of nerve and muscle signal intensity and background signal intensity at the same level of the two groups of plain images,and calculated CNR and SNR,and perform statistical analysis.Results The two observers had a good consistency in the scores of the two groups of images(Kappa≥0.461),The overall image quality scores of 3D-DIR-SPACE at low dose and 3D-STIR-SPACE at recommended dose after enhancement were 4.71±0.41 and 4.78±0.45,respectively,with no statistical difference(P>0.05).The CNR and SNR of 3D-STIR/DIR-SPACE plain scan were no significant difference(P>0.05),and the correlation was good(P=0.07).Conclusion The 3D-DIR-SPACE sequence combined with low dose enhanced scan obtains image quality with diagnostic effect in lumbosacral plexus magnetic resonance imaging.It has certain application value and is worth promoting.