目的 评价肋骨隐匿性骨折CT征 象诊断肋骨骨折的价值。方法 回顾性收 集20例21处多排螺旋CT随访证实的隐匿性 肋骨骨折患者的临床及影像资料，由3位 高年资放射医师依据隐匿性骨折征象盲法 诊断隐匿性骨折，CT征象包括线样增亮 征、皮质凹陷征、皮质翘起征与细小裂纹 征，经协商达成一致诊断意见，以CT随 访显示肋骨骨折部位为金标准，统计盲 法诊断的真阳性、真阴性、假阳性、假阴 性隐匿性骨折部位数，计算4种征象诊断 隐匿性肋骨骨折的敏感性、特异性、正确 性、阳性预期值与阴性预期值。结果 20 例21处隐匿性骨折盲法诊断真阳性15处 (71.43%)，真阴性459肋，假阳性5处，假 阴性6处；4种CT征象诊断隐匿性肋骨骨折 的敏感性为71.43%，特异性98.92%，正确 性98.75%，阳性预期值75.0%，阴性预期 值98.71%。结论 线样增亮征、皮质凹陷 征、皮质翘起征与细小裂纹征4种CT征象 可有效检出隐匿性肋骨骨折，熟悉这些CT 征象有助于减少胸部外伤病人隐匿性肋骨 骨折的漏诊。

Objective To evaluate the diagnostic value of the 4 CT signs of occult fracture of the ribs. Methods The clinical and imaging material of 20 cases with 21 occult rib fractures conformed with CT follow up were evaluated retrospectively. 3 senior radiologists with more than 3 years experiance of image diagnosis reviewed the CT images of the 20 cases and diagnosed the occult fracture blindly in consonance, according to the finding of the 4 CT signs: denser line sign (DL), cortical notch sign (CN), cortical cock up sign (CC) and tiny crack sign (TC). With the rib fractures shown by CT follow up as gold standard, calculated the number of occult fractures of true positive, true negative, false positive and false negative diagnosed with the 4 CT signs, and computed the sensitivity, specialty, accuracy, positive predictive value (PPV) and negative predictive value (NPV) of diagnosis with the 4 CT signs. Results 15 true positive (71.43%), 459 true negative, 5 false positive and 6 false negative diagnosis of rib occult fracture were made with reviewing CT images of the 20 cases on the basis of 4 CT sings blindly, and the sensitivity, specialty, accuracy, PPV and NPV were 71.42%, 98.92%, 98.75%, 75.0% and 98.71% respectively. Conclusion With the signs of DL, CN, CC and TC, occult fractures of the ribs could be detected effectively. Familiar those CT signs might reduce the missed diagnosis of rib occult fracture of the patient with thoracic trauma.