肺炎支原体感染所致儿童坏死性肺炎30例胸部CT表现及转归

Chest CT features and outcome of necrotizing pneumonia caused by Mycoplasma pneumoniae in children （ report of 30 cases）

目的总结肺炎支原体感染所致儿童坏死性肺炎（necrotizing pneumonia，NP）的胸部CT征象、转归，并对NP病例常见炎性指标变化特点进行初步探讨，对临床医师认识本病CT特点及时进行CT检查提供帮助。方法回顾分析30例肺炎支原体感染所致儿童NP的胸部CT征象，分析NP大叶肺实变及相关征象随病程进展出现的动态变化；比较NP组与24例非NP对照组的炎性指标差异。结果（1）NP组（30例）胸部CT征象：单侧大叶性实变（28例），其中20例累及1个肺叶，10例累及多个肺叶；肺空腔（27例）；增强CT扫描可见肺实变内均存在强化减低区（22例）。（2）治疗过程中NP组CT征象动态变化：病程2个月复查23例，肺实变吸收2例（9％），肺内出现空腔18例（78％），胸膜增厚16例（70％），肺不张2例（9％），胸膜瘘1例（4％）；病程3个月时复查11例，肺实变吸收7例（64％），胸膜增厚10例（91％），肺内出现空腔7例（64％），肺不张5例（45％），肺叶囊性变2例（18％），胸膜瘘1例；病程3．5年时复查10例，未见肺实变，出现肺不张4例，肺叶残留囊性变4例，遗留条索状影1例。（3）NP组与对照组常见炎性指标比较，两组间在发热持续时间（d）[25．0（12～80）与11．5（7—36）]、外周血WBC峰值（×10^9／L）[18．1（9．8—27．4）与11．1（3．1—20．5）]、中性粒细胞比率[0．814（0．397—0．928）与0．663（0．522～0．887）]、WBC异常持续时间（d）[19．5（0～67）与5．0（0—17）]、CRP峰值（mg／L）[92．1（25．6～235．0）与35．1（17．0～212．0）]、CRP异常持续时间（d）[25．0（9—53）与7．0（4．0～18．0）]差异均有统计学意义（P〈0．01）。结论肺炎支原体感染所致儿童NP胸部CT征象包括：肺叶实变以及肺实变内出现强化减低区和（或）空腔，病变吸收缓慢，转归后CT表现可大致正常或遗留条索影、肺不张或囊变。当怀疑出现坏死性改变时，密切观察某些炎性指标（如外周血WBC峰值、中性粒细胞比率、CRP峰值，发热、外周血WBC及CRP异常持续时间），有助于临床医师及时决定进行胸部CT检查，明确病变性质。

Objective To summarize the chest CT features and outcome of necrotizing pneumonia （NP） caused by Mycoplasma pneumoniae in children and to review the changes of common inflammatory parameters in NP patients to help clinicians understand the proper timing of CT scan. Method The imaging data from 30 cases of Mycoplasma pneumoniae pneumonia in NP group and 24 cases with non-necrotizing Mycoplasma penumoniae pneumonia （control group） were analyzed retrospectively. The changes of common inflammatory parameters in NP group and control group were compared. Result （ 1 ） The chest CT findings of NP （30 cases） ： 28 cases showed unilateral pneumonia, and 20 cases showed single lobar consolidation, 10 cases had multiple lobes involvement; pulmonary cavities were seen in 27 cases. There were decreased enhancement areas in the consolidation （22 cases）. （2） The dynamic changes of CT signs during follow-up ： The CT scan performed during the 1 - 2 months after onset of disease （23 cases） showed that pulmonary consolidation in 2 cases （9%） were absorbed, 18 cases （ 78% ） had cavities in lung, 16 cases （ 70% ） had pleural thickening, 2 cases （9%）atelectasis and 1 case（4% ）bronchopleural fistula;the CT scan performed during the 2 -3 months after onset of disease （11 cases） showed pulmonary consolidation in 7 cases （64%） were absorbed, 10 cases （ 91% ） pleural thickness , 7 cases （ 64% ） with cavities in lung, 5 cases （ 45% ） atelectasis,2 cases （ 18% ） pulmonary lobe cysts and 1 case bronchopleural fistula. The CT scan performed at 3.5 years of disease course （ 10 cases） showed that there were no pulmonary consolidation in any of the cases ,4 cases had atelectasis,4 cases had pulmonary cysts, and 1 case had band-like scars. （3） There were significant differences between NP group and control group in the maximum peripheral blood WBC, proportion of neutrophil and C-reactive protein （ CRP, mg/L） （ P 〈 0.01, 0.01, 0.001 , respectively）, and there was significant difference between the 2 groups in the duration of fever, abnormal WBC （d） and CRP （d） （P 〈 0. 001 ）. Conclusion The chest CT features of NP caused by Mycoplasma pneumoniae in children were single lobular consolidation in most cases, NP had decreased parenchymal enhancement and cavity in the consolidation, and recovery was slow, the outcome included recovery, atelectasis or lobar cystic degeneration. The clinicians should pay more attention to the common inflammatory parameters when they suspect the Mycoplasma pneumoniae pneumonia is progressing into necrosis and make correct decision for chest CT examination.