Schulman A, Dalrymple R B
Br J Radiol. 1978 Jul;51(607):494-7. doi: 10.1259/0007-1285-51-607-494.
Seven cases of subpulmonary pneumothorax are presented: four due to penetrating injury, two to blunt trauma and one to osteosarcoma metastasis. The typical and diagnostic appearance is a basal band of radiolucency bounded above by the thin hair-line of visceral pleura paralleling the dome of the hemi-diaphragm. When partially clotted blood is also present, the appearance becomes less typical and has to be differentiated from traumatic diaphragmatic herniation of bowel and from traumatic pneumatocoele by barium studies and by decubitus radiographs respectively. It is the bridge-like disposition of the pleural cavity between the dome of the hemi-diaphragm and the hollowed concavity of the lung base which allows pneumothorax to collect in it. It is rarely seen because blebs and bullae which are the commonest causes of pneumothorax are most often located in the upper zones.
本文报告7例肺下气胸：4例因穿透伤所致，2例因钝性创伤所致，1例因骨肉瘤转移所致。典型的诊断性表现是一条位于基底的透亮带，其上方由平行于半膈肌穹窿的脏层胸膜细发丝状线界定。当同时存在部分凝血块时，表现变得不那么典型，必须分别通过钡剂造影和卧位X线片与外伤性肠膈疝和外伤性肺气囊相鉴别。正是半膈肌穹窿与肺底部凹陷之间胸腔的桥状结构使得气胸能够积聚其中。这种情况很少见，因为作为气胸最常见原因的肺大疱和肺气囊大多位于上肺区。
