Diaphragm muscle fiber dysplasia or atrophy, the position of the diaphragm upward, congenital and acquired two kinds, congenital diaphragmatic dilatation refers to the embryonic diaphragm developmental disorders, underdevelopment, intra-abdominal positive pressure and negative pressure in the thoracic cavity increases, the diaphragm itself gradually elongation and thinning, rising into the thoracic cavity, the diaphragm or part of the developmental insufficiency, resulting in a total diaphragm or unilateral diaphragmatic dilatation; localized involvement can be caused by some of the diaphragmatic dilatation (such as the anterior, posterior lateral and median parts of the diaphragm). Localized involvement may cause partial diaphragmatic expansion (e.g. anterior, posterior-lateral, and median). Congenital diaphragmatic dilatation can be combined with other visceral malformations, such as pulmonary hypoplasia, gastric reversal, intestinal malrotation and ectopic high kidney, etc. Acquired diaphragmatic dilatation is mostly caused by phrenic nerve damage resulting in diaphragmatic paralysis, and diaphragmatic dilatation can be complicated by subphrenic infections. Localized diaphragmatic bulge is mostly seen on the right side. If the diaphragmatic bulge is complete, the angle of the esophagus into the stomach can be reduced, and food passage is impeded, resulting in reflux. The fundus of the stomach may also be twisted or elevated, making it difficult for food to pass through the cardia and pylorus. Children with complete diaphragmatic dilatation may have difficulty breathing, loss of appetite, and intermittent intestinal obstruction. Unilateral and limited diaphragmatic dilatation is asymptomatic. The disease can occur at any age and is more common in males than females, with a ratio of approximately 2-3:1. Pathology There is no consensus on the cause of the disease. Lateralization occurs most often on the left side, limited anteriorly within the diaphragmatic apex on the right side, and both can occur on both sides, but are rarer. Most believe that the diaphragm is due to the diaphragm all or partial hypoplasia, atrophy and spleen caused by the diaphragm, in the pathology of the diaphragm for a layer of fibrous membrane, in addition to diaphragm fibrous congenital developmental anomalies, may be related to the secondary method and pulmonary hypoplasia so that the diaphragm descending ability to weaken. The acquired nature is mostly caused by neurogenic and myogenic factors. For example, trauma, surgery, mediastinal disease and other injuries to the nerves and abdominal pressure increase, chest pressure decrease and other factors lead to the development of the disease. Clinical manifestations: generally without any conscious symptoms, or cough, dyspnea, chest pain, epigastric discomfort, vomiting, dysphagia and so on. Neonates with severe dyspnea and cyanosis due to diaphragmatic expansion compressing the heart and swinging of the mediastinum are in urgent need of surgical treatment. Imaging manifestations 1. The top of the diaphragm shows a complete arcuate shadow, which is significantly elevated up to the third and fourth posterior ribs or up to the second intercostal space. The right side of the diaphragm is easy to be mistaken for free gas because of the interstitial colon that can easily occur when the right side of the diaphragm is inflated. 2. The motility of the diaphragm is weakened, completely disappeared, or even contradictory movements occur. 3.Diaphragmatic expansion produces the sign of pushing pressure, the heart shadow mediastinum moves to the healthy side, and the mediastinum swings obviously with respiration. Discoidal atelectasis may appear when lung tissue is compressed. 4.Diaphragmatic elevation occurs on the left side if accompanied by gastric torsion, and the stomach is turned over in the longitudinal axis by barium meal examination, which is tightly attached to the lower part of the diaphragm like a shrimp. 5, due to the scarcity of muscle fibers, or even lack of diaphragm thinning, CT three-dimensional imaging was arc-shaped shadow. Restricted diaphragmatic expansion is mostly seen in the right side of the inner anterior, semi-circular shadow, protruding to the lung field, uniform density, clear boundary, inhalation is obvious, exhalation flattens, deep breathing may not be displayed. Lateral view overlaps with the cardiac shadow, with increased local density, very similar to interlobar effusion or middle lobe lesion.CT three-dimensional demonstrates a limited and prominent hepatic shadow under the apex of the diaphragm corresponding to the diaphragmatic range of the diaphragm elevation. The lateral view overlaps with the cardiac shadow, which is slightly posterior and solid on the right side, whereas on the left side it is anterior and is an air-containing gastric vesicle shadow.