图示肺纤维化。一些限制性肺疾病的病因不明(如图)，称为特发性肺纤维化。肺泡炎引起成纤维细胞增生和胶原沉积。
This is an example of pulmonary fibrosis. Some cases of restrictive lung disease have no known etiology--this is, they are known as idiopathic pulmonary fibrosis. The alveolitis that produces fibroblast proliferation and collagen deposition is progressive over time.
