A 30-year-old man is hospitalized after a motor vehicle accident in which he sustains blunt trauma to his chest. On physical examination, there are contusions to the right side of the chest, but no lacerations. Within 1 hour after the accident, he develops sudden difficulty breathing and marked pain on the right side. Vital signs now show that he is afebrile; his pulse is 80/min, respirations are 30/min and shallow, and blood pressure is 100/65 mmHg. Breath sounds are not audible, and there is tympany to percussion on the right side. Which of the following radiographic findings for this man is shown in the figure?
A Interstitial fibrosis
B Patchy infiltrates
C Pleural effusion
D Pneumothorax
E Ventilation/perfusion mismatch

本题胸片

审题

钝伤和撕裂伤分别是什么？
什么是持续性钝伤（sustains blunt trauma）？这个“持续”作何解释？
抛开本案例，呼吸音未闻及（Breath sounds are not audible）提示什么？

做题

自选答案：D
题目类型：b

标准答案：D
答案解析：Blunt trauma to the chest can lead to rib fracture. The sharp bone can penetrate the pleura and produce an air leak, resulting in pneumothorax. Although pneumothorax can complicate rupture of a bulla in emphysema, this is more likely to occur in paraseptal emphysema or distal acinar emphysema than in centrilobular emphysema with increased anteroposterior diameter.
Although pulmonary embolus with V/Q mismatch and pneumonia with patchy infiltrates are possible complications in hospitalized patients, they would not occur this quickly.
Pleural space fluid (hydrothorax) and edema are unlikely from trauma alone; hemorrhage is more likely. Interstitial disease would produce more opacity, not less.

阅片：
右侧肺野低密度，肺纹理消失
左侧可见一低密度区
左侧可见点片状高密度影

知识辐射

胸片的阅读-丁香园
胸片上人体组织的密度与组织的种类有关，也与组织的厚度有关，在病理状态下组织的固有密度与厚度发生改变，则出现黑白灰度的对比。

反思

• 这道题并没有理解障碍，但是误省还是造成了时间上的浪费，题干最后一句是要求：根据胸片描述所见的征像。而我没有看胸片直接就根据休克体征、呼吸困难、剧烈胸痛认定是气胸。这道题虽然答案选出来了，却等于没做。
  由于影像医学学的很菜，加之没有上临床，这张片子看的很困难。
• 我到现在依然有一些疑问，这个图片右侧肺野虽然能看到大片低密度影，但是为什么没有看到由于含气量变少而密度略微升高的肺组织影？
• 左侧可见一片低密度影，不清楚是个什么结构，看答案的意思不知道是不是肺大疱，答案解析也看不明白，为什么说着气胸却突然跳到肺气肿上面去了，难道是因为一侧气胸导致的健侧代偿？
• 答案解析还提到了胸腔积液，或许是因为左侧肋膈角变钝了？高老爷子认为胸腔积液（hydrothorax）不会发生在这种急性创伤之中，这更应该是胸腔积血（hemothorax），我一直觉得这两个是包含关系。
  肺栓塞与肺炎在这种急性创伤住院患者中，短时间一般不会出现。至于斑片状影，并不确定有没有