青少年特发性脊柱侧凸主弯侧凸Cobb角、胸椎后凸角及腰椎前凸角仰卧位MRI与站立位X线测量的对比研究

Comparison between supine MRI and standing X-ray in the measurement of Cobb angle, thoracic ;kyphosis and lumbar lordosis in adolescent idiopathic scoliosis

目的：探讨仰卧位MRI与站立位X线全脊柱片在青少年特发性脊柱侧凸（ AIS）患者侧凸Cobb角、胸椎后凸角（ TK）及腰椎前凸角（ LL）测量上的差异性和相关性。方法选取2008年1月—2016年1月行外科支具治疗或手术治疗且密切随访的120例AIS患者的站立位X线全脊柱片和仰卧位MRI全脊柱重建片资料进行回顾性分析。于站立位X线全脊柱正侧位片上分别测量主弯侧凸Cobb角、TK及LL。于患者仰卧位MRI全脊柱冠状面和矢状面重建片上的相同节段测量侧凸Cobb角、TK和LL。应用配对t检验及线性回归分析两组之间测量值的差异性及相关性。结果120例站立位X线片上和仰卧位MRI上主弯侧凸Cobb角分别为33.8°±20.1°和24.9°±18.3°,TK分别为15.2°±9.7°和10.5°±7.7°,LL分别为43.6°±13.8°和37.1°±13.5°,差异均有统计学意义（P值均〈0.01）。线性相关分析显示,站立位X线片上和仰卧位MRI上主弯侧凸Cobb角、TK和LL均有相关性, r 分别为0.920、0.706和0.565（ P 值均〈0.01）。线性回归分析得回归方程为：^Y站立位X线侧凸Cobb角=0.901× X仰卧位MRI侧凸Cobb角＋12.517、^Y站立位X线TK =1.055× X仰卧位MRI TK ＋3.865、^Y站立位X线LL=0.718× X仰卧位MRI LL ＋17.135。结论仰卧位MRI与站立位X线片在AIS患者主弯侧凸Cobb角、TK及LL的测量具有差异且呈线性相关,利用仰卧位MRI可计算出站立位X线片上患者的侧凸Cobb角、TK和LL。

Objective To study the difference and correlation between supine MR total spine imaging and standing whole-spine X-ray in the measurement of Cobb angle, thoracic kyphosis （ TK） and lumbar lordosis （ LL） in adolescent idiopathic scoliosis （ AIS） patients. Methods A total of 120 AIS patients between 2008 and 2016 with both supine MRI and standing X-ray were retrospectively reviewed. From the standing X-rays, the Cobb angles of main curve, TK and LL were measured. On supine MRI, the coronal Cobb angles, TK and LL were also measured at the same levels accordingly. The comparison between 2 groups was analyzed with paired t test and the correlation was studied using linear regression analysis. Results The average Cobb angles measured on standing X-ray and supine MRI were 33. 8° ± 20. 1° and 24. 9° ± 18. 3°, respectively （P〈0. 01）. The TK were 15. 2° ± 9. 7° and 10. 5° ± 7. 7° for X-ray and MRI（P〈0. 01）, while the LL averaged 43. 6° ± 13. 8° and 37. 1° ± 13. 5° for X-ray and MRI（P〈0. 01）, respectively. The standing X-ray was significantly linearly correlated with supine MRI in terms of Cobb angles, TK and LL with the r values were 0. 920,0. 706 and 0. 565, respectively （P〈0. 01）. The linear regression equations were as follows： ^YCobb angle on standing X-ray =0. 901 × XCobb angle on supine MRI ＋12. 517,^YTK on standing X-ray = 1. 055 × XTK on supine MRI ＋ 3. 865, ^YLL on standing X-ray = 0. 718 × XLL on supine MRI ＋ 17. 135. Conclusions The coronal Cobb angle, TK and LL measured on supine MRI are significantly linearly correlated with the Cobb angles measured on standing X-ray in AIS patients. Therefore, the supine MRI could serve as a reliable alternative to standing X-ray in the assessment of coronal Cobb angle, TK and LL using the calculated equations.