第三代Force双能量CT对骶骨翼骨挫伤及隐匿性骨折的临床诊断价值

Diagnostic value of the third generation Force dual energy CT in contusion and occult fracture of sacral pterygoid bone

目的:探讨第三代Force双能量CT虚拟去钙(DECT-VNCa)图在不同对比物质相对比值(RCMR)条件下对骶骨翼骨挫伤及隐匿性骨折的临床诊断价值。方法:收集2017年1月至2020年2月温州医科大学附属第五医院有明确骨盆外伤史或腰骶部疼痛的35例患者,行双源CT双能量扫描及MRI检查,RCMR值分别取1.59、1.79、1.89,重建3组DE-VNCa图像。以MRI诊断为金标准,计算3组图像诊断骶骨翼骨挫伤及隐匿性骨折的效能,获得最优RCMR值,并在此最优条件下测量并比较骶骨翼骨髓水肿区与对侧正常区域的CT值,以ROC曲线评价CT值对骶骨翼隐匿性骨折的诊断效能。结果:RCMR值取1.59、1.79、1.89时,诊断骶骨翼骨髓水肿的约登指数分别为0.40、0.81、0.71;RCMR为1.79时,DE-VNCa图诊断效能最高。以RCMR=1.79重建DE-VNCa图,骨髓水肿区域平均CT值为(-20.21±18.81)Hu,对侧正常骨髓区平均CT值为(-74.19±27.94)Hu,骶骨翼骨髓水肿区与对侧正常区域的CT值差异有统计学意义(P<0.001)。以CT值=-43.45 Hu为临界值,诊断骶骨翼骨髓水肿的AUC为0.947(P<0.001)。结论:双源DECT-VNCa图在RCMR为1.79时诊断骶骨翼骨挫伤及隐匿性骨折的临床价值较高;CT值有助于诊断骶骨翼骨挫伤及隐匿性骨折骨髓水肿。

Objective:To explore the value of the third generation Force dual energy CT virtual noncalcium(DECT-VNCa)map in the diagnosis of contusion and occult fracture of sacral alar under the condition of different relative contrast material ratio(RCMR).Methods:Totally 35 patients with definite history of pelvic trauma or lumbosacral pain in the past 3 years were prospectively collected for dual source CT dual energy scan and MRI examination.The RCMR values were 1.59,1.79,1.89,respectively.Three groups of DE-VNCa images were reconstructed.Taking MRI diagnosis as the gold standard,the efficacy of three groups of images was calculated in the diagnosis of sacral pterygoid bone contusion and occult fracture,and the optimal RCMR value was obtained.Under this optimal condition,the CT values of sacral alar bone marrow edema area and contralateral normal area were measured and compared,and then the diagnostic efficacy of CT value in sacral alar occult fracture was evaluated by ROC curve.Results:When the RCMR values was 1.59,1.79 and 1.89,the diagnostic efficacy of DE-VNCa was the highest,when Yoden index for the diagnosis of sacral alar bone marrow edema was 0.40,0.81 and 0.71 respectively.Using RCMR=1.79 to reconstruct DE-VNCa map,the average CT value of bone marrow edema area was(-20.21±18.81)Hu,and the average CT value of contralateral normal bone marrow area was(-74.19±27.94)Hu.There was significant difference between sacral alar bone marrow edema area and contralateral normal area(P<0.001).Taking CT=-43.45 Hu as the critical value,the AUC for diagnosis of sacral alar bone marrow edema was 0.947(P<0.001).Conclusion:Dual source CT DE-VNCa is of high clinical value in the diagnosis of sacral pterygoid bone contusion and occult fracture when RCMR is 1.79,and CT value is helpful in the diagnosis of sacral pterygoid bone contusion and bone marrow edema of occult fracture.