肋骨骨折MSCT隔期联合诊断法的临床应用

Clinical Application of the Combined Diagnosis Method of MSCT Scan at Different Period in Rib Fracture

目的：探讨肋骨骨折MSCT隔期联合诊断法（简称隔期联合诊断）的应用价值.方法：回顾分析经隔期联合诊断的53例肋骨骨折患者资料.首次MSCT采用常规剂量,提示创伤4周后复查.复查预扫描错位最轻的骨折,骨性骨痂明显、密度较低者以50mA、120mA的低剂量扫描全部肋骨,不明显者2周后以120mA的低剂量扫描全部肋骨.由2名放射科医师评估低剂量图像诊断可接受率、主观噪声,通过对比观察首次及骨性骨痂形成期薄层图像确定骨折数.以Wilcoxon配对符号秩和检验比较两次（首次及隔期联合诊断）诊断结果的差异,以Kappa检验评价两位医师评估结果的一致性.结果：首次诊断肋骨骨折234处、疑似骨折26处,隔期联合诊断诊断肋骨骨折313处.64.15％的患者两次诊断不一致,首次有34处不完全性、28处无错位完全性、2处隐性骨内骨折未显示,26处疑似骨折经复查诊断骨折15处、排除骨折11处.两次诊断结果差异有统计学意义（Z值=5.018,P＜0.01）.清晰可见的骨性骨痂发现于4周末～5周41例,4周末未发现6周清晰可见11例,5周未发现7周清晰可见1例.两位医师评估结果获得近乎完美的一致（Kappa值为0.863、0.826、0.838、0.826）.结论：隔期联合诊断可良好把握肋骨骨折复查时机,避免首次MSCT有可能发生的漏诊,降低患者辐射量.

Purpose：To explore the clinical application value of the combined diagnosis method of MSCT scan at different periods in rib fracture.Methods：Fifty-three patients with rib fractures by using the combined diagnosis method of MSCT scan at different periods were analyzed retrospectively.They were all checked after the first time MSCT scans by using conventional scan mode and were prompted and rechecked about 4 weeks after trauma.The mild fractures first diagnosed were pre-scanned repeatedly.Those patients with low dense and density osseous callus were rechecked with 50mA and 120mA total ribs MSCT scan respectively.No clear callus patients were rechecked with 120mA MSCT scan after 2 weeks.Image quality of MSCT using low dose were assessed,thin-slice images in first time and bony callus formation periods were compared by 2 experienced radiologists and then the fracture numbers were determined.The differences of diagnosis results with two methods were tested using the Wilcoxon signed rank sum test.The differences of the interobserver were determined by Kappa statistics.Results：There were 234 fractures and 26 doubtful fractures at first time MSCT,313 fractures by using the combined diagnosis method at different periods.（Z=5.018,P 〈0.01）.Of all the patients,64.15% were inconsistent between two diagnosis results.In the first time exam,34 incomplete fractures,28 non-displacement complete fractures and 2 occult interosseous fractures cannot be shown.To those 26 doubtful fractures,15 case were diagnosed as fracture and 11 case were excluded.Fortyone cases were found with visible bony callus at the end of 4 week and 5 week,11 cases were not found with visible bony callus at the end of 4 week and were found at 6 week,1 case was found with visible bony callus at 7 week and not in 5 week.There was prefect concordance of inter-observers in diagnostic acceptability （Kappa =0.863、0.826、0.838、0.826）.Conclusions：The combined diagnosis method of MSCT scan at different periods can assist to optimize the reexamination timing for rib fractures,and avoid missed diagnosis and reduce the r adiation dose.