磁共振波谱成像定量腰椎骨髓脂肪短中期的可重复性研究

Short-and Mid-term Reproducibility of Lumbar Vertebral Bone Marrow Fat Content Measurements Using Magnetic Resonance Spectroscopy

目的评价磁共振波谱成像(MRS)定量腰椎骨髓脂肪短、中期的可重复性。方法选择2015年3—6月在温州市第七人民医院和温州市中医院健康体检中心体检的符合入选标准的健康女性(28.9~48.6岁)受检者30位,基线(即研究开始时)及6个月时测定受检者血25羟维生素D、骨钙素、β-胶原降解产物及雌二醇。于基线、6周及6个月时分别行3次MRS扫描,测定腰3椎体骨髓脂肪分数(FF)。由2位评定者独立测定FF,计算组内相关系数(ICC),评价不同时间点(短期和中期)MRS测定FF的精确性。结果共22位受检者完成研究。评定者间与评定者内在基线、6周及6个月时测定FF的ICC为0.931~0.988。Bland-Altman法分析显示,评定者间、评定者内测定FF的差值均落于95%可信区间内。短期和中期MRS测定FF的ICC为0.856~0.944,变异系数为2.45%~4.72%。结论短、中期MRS测定腰椎骨髓脂肪含量具有良好的可重复性。

Objective To investigate the short - and mid - term reproducibility of lumbar vertebral bone marrow fat fraction （FF）measurements using magnetic resonance spectroscopy （MRS）. Methods The selected participants meeting the inclusion criteria of this study were 30 healthy females （aged 28. 9 to 48. 6 years）who underwent physical examination in Physical Examination Center of the Seventh People′s Hospital of Wenzhou and Wenzhou Hospital of Traditional Chinese Medicine from March to June in 2015. The following clinical parameters were collected,serum 25 - hydroxy vitamin D,osteocalcin,β -CTx and estradiol measured at baseline （at the beginning of study）and 6 months after the beginning of study. At baseline,6 weeks and 6 months after the beginning of study,MRS scanning was performed in the participants,and the 3rd lumbar vertebra （L3）bone marrow FF was determined by two independent raters,respectively. The short - （at both baseline and 6 weeks after the beginning of study）and mid - term （at 6 months after the beginning of study）accuracy of MRS - based FF measurements was assessed by using interclass correlation coefficient （ICC）,Bland - Altman plot and coefficient of variance （CV）. Results Twenty - two participants completed the study. The inter - and intra - rater agreement for FF measurements at baseline,6 weeks and 6 months after the beginning of study was excellent （ICC ranged from 0. 931 to 0. 988）. All data points calculated using the Bland - Altman plot,were within the 95% limits of agreement;the ICC for the short - and mid - term agreement was excellent （ICC ranged from 0. 856 to 0. 944）;the CV for the reproducibility of FF measured over the short - and mid - term was 2. 45%- 4. 72%. Conclusion MRS is a reproducible method for short - and mid - term quantification of lumbar vertebral bone marrow fat content.