双能量CT虚拟非钙化成像诊断椎体骨挫伤及隐匿性骨折的临床价值研究

Study on clinical value of dual-energy CT virtual non-calcium imaging in the diagnose of vertebral bone contusion and occult fracture

目的探讨双能量CT(DECT)虚拟非钙化(VNCa)成像诊断椎体骨挫伤及隐匿性骨折的临床价值。方法选取椎体骨挫伤及隐匿性骨折患者118例,均接受双能量CT及磁共振成像(MRI)检查。根据年龄分为<60岁组和≥60岁组,在VNCa成像上对两组胸腰椎骨髓水肿CT值与正常椎体CT值、CT值差值(△CT)与正常椎体CT值之间分别建立配对样本t检验及受试者工作特征曲线(ROC曲线)分析,计算两组胸腰椎骨髓水肿CT值、△CT的截断点、曲线下面积(AUC)、灵敏度、特异度。结果118例患者均完成MRI及双能量CT检查,以MRI为金标准,共确诊123个椎体骨髓水肿,<60岁组腰椎骨折33个,胸椎骨折14个;≥60岁组腰椎骨折45个,胸椎骨折27个;另有骶椎骨折2个,颈椎骨折2个。≥60岁组更容易发生椎体骨折,两组均以腰椎骨折居多。在VNCa成像上对腰椎、胸椎骨髓水肿CT值进行定量分析,两组骨髓水肿椎体CT值均高于相邻正常椎体CT值,差异均具有统计学意义(P<0.05)。ROC曲线分析显示:<60岁组腰椎、胸椎骨髓水肿CT值截断点、AUC、灵敏度、特异度分别为14.60 Hu、0.87、94.1%、76.5%和-15.75 Hu、0.74、93.3%、76.7%,≥60岁组腰椎、胸椎骨髓水肿CT值截断点、AUC、灵敏度、特异度分别为2.20 Hu、0.93、91.3%、84.8%和9.95 Hu、0.90、88.6%、89.3%。在VNCa成像上对腰椎、胸椎骨髓水肿△CT进行定量分析,差异均具有统计学意义(P<0.05)。ROC曲线分析显示:<60岁组腰椎、胸椎骨髓水肿△CT截断点、AUC、灵敏度、特异度分别为6.90 Hu、0.90、95.6%、80.6%和3.25 Hu、0.82、94.8%、86.7%,≥60岁组腰椎、胸椎骨髓水肿△CT截断点、AUC、灵敏度、特异度分别为9.40 Hu、0.99、97.5%、95.4%和4.50 Hu、0.94、96.4%、85.7%。结论将椎体骨髓水肿△CT、骨髓水肿CT值联合使用可以极大的提高双能量CT诊断椎体骨挫伤及隐匿性骨折的效能,并且基本能达到与MRI诊断椎体骨髓水肿同样的效能,也可以弥补MRI诸多禁忌证带来的不便。

Objective To explore the clinical value of dual-energy CT(DECT)virtual non-calcium(VNCa)imaging in the diagnose of vertebral bone contusion and occult fracture.Methods A total of 118 patients with vertebral bone contusion and occult fracture were selected,all of whom underwent dual energy CT and magnetic resonance imaging(MRI).According to their age,the patients were divided into<60-year-old group and≥60-year-old group.Paired-samples t-test and receiver operating characteristic(ROC)curve analysis were established on VNCa imaging between the CT value of lumbar and thoracic bone marrow edema and the CT value of normal vertebrae,as well as the CT value difference(△CT)and the CT value of normal vertebrae.The CT value of lumbar and thoracic bone marrow edema,cut-off point of△CT,area under the curve(AUC),sensitivity and specificity of the two groups were calculated.Results MRI and dual-energy CT were completed in 118 patients,and MRI was used as the gold standard to confirm the diagnosis of 123 vertebral bone marrow edema,with 33 lumbar fractures and 14 thoracic fractures in the<60-year-old group;45 lumbar fractures and 27 thoracic fractures in the≥60-year-old group;and 2 sacral vertebral fracture and 2 cervical vertebral fractures.Vertebral fractures were more likely to occur in the≥60-year-old group,with lumbar fractures predominating in both groups.The CT values of lumbar and thoracic bone marrow edema were quantitatively analyzed on VNCa imaging,and the CT values of vertebrae with bone marrow edema were higher than those of adjacent normal vertebrae in both groups,and the differences were statistically significant(P<0.05).ROC curve analysis showed that the cut-off point,AUC,sensitivity and specificity of CT value of lumbar and thoracic bone marrow edema in<60-year-old group were 14.60 Hu,0.87,94.1%,76.5%and-15.75 Hu,0.74,93.3%,76.7%,while those in the≥60-year-old group were 2.20 Hu,0.93,91.3%,84.8%and 9.95 Hu,0.90,88.6%,89.3%.The△CT value of lumbar and thoracic bone marrow edema was quantitatively analyzed on VNCa imaging.The differences were statistically significant(P<0.05).ROC curve analysis showed that the cut-off point,AUC,sensitivity,and specificity of△CT value of lumbar and thoracic bone marrow edema in the<60 years old group were 6.90 Hu,0.90,95.6%,and 80.6%and 3.25 Hu,0.82,94.8%,and 86.7%,while those in the≥60-year-old group were 9.40 Hu,0.99,97.5%,95.4%and 4.50 Hu,0.94,96.4%,85.7%,respectively.Conclusion The combination of△CT of vertebral bone marrow edema and CT of bone marrow edema can greatly improve the efficacy of dual-energy CT in the diagnosis of vertebral bone contusion and occult fracture,and such combination could achieve basically the same performance as MRI for the diagnosis of vertebral bone marrow edema and could also make up for the inconvenience caused by various MRI contraindications.