患者 ,女性 ,40岁。因咳嗽一周就诊。平时经常咳嗽 ,二年前发热咳血痰一次。检查 :左肺呼吸音较右侧弱 ,实验室检查血沉 18ｍｍ /ｈ。胸正侧位片见相当于左下肺叶背段区一类圆形密度均匀增高阴影 ,大小约 5ｃｍ× 5ｃｍ× 6ｃｍ ,边缘锐利但下缘欠清晰 ,似有分叶 ,与胸壁不相连 Patient, female, 40 years old. Get a doctor for a cough week. He often coughs, fever coughing and bleeding twice a year ago. Examination: The left lung breath sounds are weaker than the right side, and laboratory tests are performed with an erythrocyte sedimentation rate of 18 mm/h. The thoracic and lateral radiographs are equivalent to the left lower lobe segment of the dorsal area with a uniform increase in the density of a circular shape, the size of about 5cm × 5cm × 6cm, sharp edges but less clear at the lower edge, similar to the lobes, not connected with the chest wall