能谱CT在评估膝关节急性外伤性骨髓水肿中的应用价值

The value of dual-energy CT in the evaluation of acute traumatic bone marrow edema of knee joint

目的探讨能谱CT在膝关节急性外伤性骨髓水肿中的应用价值。方法选取行能谱CT和MRI检查的急性膝关节外伤患者32例。能谱CT扫描数据传输到后处理工作站AW4.7,以MRI作为参考标准,由2位诊断医师分别利用能谱水-钙(Ca)、水-羟基磷灰石(Hap)彩色编码图像评估骨髓水肿程度,比较两种方法评估骨髓水肿差异有无统计学意义;测量水肿区域的水-Ca、水-Hap值,评价差异有无统计学意义,并利用ROC曲线分析两者在骨髓水肿中的诊断效能。结果32例膝关节外伤,MRI显示骨髓水肿区域146处,能谱CT中:水-Ca彩色编码图像共获得135处水肿区域,灵敏度为95.6%,特异度为98.8%,阳性预测值为96.3%,阴性预测值为98.5%;水-Hap彩色编码图像共获得128处水肿区域,灵敏度为90.4%,特异度为98.8%,阳性预测值为96.1%,阴性预测值为96.9%;MRI、水-Ca、水-Hap三者之间差异无统计学意义(P>0.05)。ROC分析显示在水-Ca中,当相对水含量值为1020.02 mg/cm3时,能谱CT对骨髓水肿的诊断效能最高,灵敏度99.3%,特异度74.1%,AUC为0.93;在水-Hap中,当相对水含量值为953.99 mg/cm^(3)时,能谱CT对骨髓水肿的诊断效能最高,灵敏度88.1%,特异度93.3%,AUC为0.96,差异有统计学意义(P<0.001)。结论能谱CT的水-Ca、水-Hap均可以清晰显示急性膝关节外伤患者的骨髓水肿区域,并精准定量评估:MRI、水-Ca、水-Hap彩色编码图像显示骨髓水肿区域差异无统计学意义;利用ROC曲线分析显示水肿区域的水-Ca、水-Hap值在骨髓水肿中的诊断效能差异有统计学意义。

Objective To evaluate the value of dual-energy CT in the evaluation of acute traumatic bone marrow edema of knee joint.Methods Thirty-two patients with acute knee joint trauma who underwent dual-energy CT and MRI between were retrospectively analyzed.The images were transferred to AW4.7 post-processing workstation for further analysis.Taking MRI as the reference standard,two diagnostic physicians used energy spectrum water-calcium(Ca)and water-hydroxyapatite(Hap)substance decomposition pseudo-color images to evaluate the degree of bone marrow edema,and compared the statistical difference between the two methods.The values of water-Ca and water-Hap in the edema area were measured to evaluate whether there was a statistical difference and the diagnostic efficacy of water-Ca and water-Hap in bone marrow edema was analyzed by ROC curve.Results In 32 cases of knee joint trauma,146 bone marrow edema areas were shown by MRI.In energy spectrum CT:135 bone marrow edema areas were obtained by water-Ca decomposition pseudo-color image,with sensitivity of 95.6%,specificity of 98.8%,positive predictive value of 96.3%and negative predictive value of 98.5%.A total of 128 edema areas were obtained from the pseudo-color images of water-HAP decomposition,with sensitivity of 90.4%,specificity of 98.8%,positive predictive value of 96.1%and negative predictive value of 96.9%.There were no significant differences among MR,water-Ca and water-HAP(P>0.05).ROC analysis showed that in water-Ca,when the relative water content value was 1020.02 mg/cm^(3),dual-energy CT had the highest diagnostic performance for bone marrow edema,with a sensitivity of 99.3%,a specificity of 74.1%,and an AUC of 0.93.In water-Hap,when the relative water content value was 953.99 mg/cm^(3),dual-energy CT had the highest diagnostic performance for bone marrow edema,with a sensitivity of 88.1%,a specificity of 93.3%,and an AUC of 0.96;the difference was statistically significant(P<0.001).Conclusion Both water-Ca and water-Hap of dual-energy CT can clearly display the bone marrow edema in patients with acute knee joint trauma and can accurately quantitatively evaluate.Compared with MRI,water-Ca and water-Hap pseudo-color images show no significant difference in bone marrow edema area.The water-Ca and water-Hap values in the edema area are measured,and the diagnostic performance of the two in bone marrow edema is statistically significant by ROC curve analysis.