Abstract: Mycoplasma pneumoniae pneumonia (MPP) is the most common type of community-acquired pneumonia in children in China. Early identification of severe cases, appropriate treatment, and reduction of sequelae are the crucial elements in the diagnosis and treatment of MPP. The pathogenesis of MPP is characterized by direct respiratory tract damage caused by mycoplasma pneumoniae and aberrant host immune response. Pathologic manifestations include pulmonary airway and interstitial inflammation, plastic bronchitis, alveolar inflammatory exudation, necrotizing pneumonia, pulmonary artery embolism, and pleural effusion. Radiographic imaging plays an important role in the severity determination and prognostic assessment of MPP. The main imaging features include plastic bronchiolitis, tree bud sign, centrilobular nodule, tree mist sign, pulmonary consolidation, pulmonary necrosis, pulmonary artery embolism, and pleural effusion. Notably, pulmonary necrosis and pulmonary artery embolism are important indications for the diagnosis of severe MPP. Clinical symptoms of pulmonary necrosis are characterized by persistent high fever and elevated CRP levels. Pulmonary embolism manifestations include chest pain and/or hemoptysis, elevated D-dimer, and bloody pleural effusion. With advancements in related research, this article presents a graphic-text analysis on the imaging features, pathogenesis and pathological manifestations of MPP. We also summarize the correlation between various imaging features and clinical characteristics of MPP, aiming to improve the understanding of MPP in children among pediatricians and radiologists.

Key words: Mycoplasma pneumoniae, Pneumoniae, Children, Pathological manifestation, Imaging manifestations