BACKGROUND:Lung ultrasound (LUS) is a bedside technique that can be used on diagnosis and follow-up of neonatal respiratory diseases. However, there are rare reports on the ultrasound features of bronchopulmonary dysplasia (BPD) which is one of the most common chronic lung diseases in preterm infants. OBJECTIVE:To describe the ultrasound features of different BPD levels, and to investigate the value of ultrasound in evaluating moderate-to-severe BPD. METHODS:In this prospective cohort study, newborns of less than 37 weeks’ gestational age in neonatal intensive care unit (NICU) were included. The LUS characteristics including pleural line, alveolar-interstitial syndrome (AIS), retrodiaphragmatic hyperechogenicity and diaphragmatic morphology were observed and recorded. The reliability of LUS in evaluating moderate and severe BPD were compared and calculated. RESULTS:A total of 108 infants were enrolled in our study: 39, 24, 29, 16 infants had non, mild, moderate and severe BPD. The median(IQR) pleura thickness in the moderate-to-severe BPD group was 1.7(1.6–1.85) mm, which was thicker than that in the none-to-mild BPD infants (P < 0.001), meanwhile the proportions of rough pleural lines, diffuse AIS, retrodiaphragmatic hyperechogenicity, small cysts above the diaphragm and rough diaphragm in the moderate-to-severe BPD group were also higher than those in none-to-mild BPD group (86.7% vs 36.5, 57.8% vs 7.9%, 37.8% vs 0, 33.3% vs 0, P < 0.001). In evaluating moderate-to-severe BPD, rough pleura had 91.1% (95% confidence interval [CI]: 0.793–0.965) in sensitivity, 91.3% (95% CI: 0.797–0.966) in negative predictive value (NPV), and 66.7% (95% CI: 0.544–0.771) in specificity. Small cysts had 100% (95% CI: 0.941-1) in specificity, 100% (95% CI: 0.816-1) in PPV, and 37.8% in sensitivity (95% CI: 0.251–0.524). Rough diaphragm had 100% (95% CI: 0.943-1) in sensitivity, 100% (95% CI: 0.796-1) in PPV and 33.3% (95% CI: 0.211–0.478) in specificity. CONCLUSIONS:Depending on its unique advantages such as convenient, no radiation and repeatable, LUS is a valuable imaging method in assessing the severity of BPD, especially in moderate and severe BPD.

中文翻译：

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支气管肺发育不良早产儿的肺部超声成像特征

背景：肺超声（LUS）是一种床旁技术，可用于新生儿呼吸系统疾病的诊断和随访。然而，关于早产儿最常见的慢性肺部疾病之一支气管肺发育不良（BPD）的超声特征的报道却很少。目的：描述不同BPD水平的超声特征，探讨超声评价中重度BPD的价值。方法：在这项前瞻性队列研究中，纳入新生儿重症监护病房 (NICU) 中小于 37 周胎龄的新生儿。观察并记录LUS特征，包括胸膜线、肺泡间质综合征（AIS）、膈后高回声和膈肌形态。比较和计算LUS评估中度和重度BPD的可靠性。结果：共有108名婴儿参加了我们的研究：39名、24名、29名、16名婴儿患有非、轻度、中度和重度BPD。中重度 BPD 组胸膜厚度中位数（IQR）为 1.7（1.6~1.85）mm，较非至轻度 BPD 婴儿厚（P < 0.001），同时粗糙的比例中重度 BPD 组的胸膜线、弥漫性 AIS、膈后高回声、膈上小囊肿和粗膈也高于非轻度 BPD 组（86.7% vs 36.5、57.8% vs 7.9% , 37.8% vs 0, 33.3% vs 0, P < 0.001)。在评估中度至重度 BPD 时，粗糙胸膜的敏感性为 91.1%（95% 置信区间 [CI]：0.793–0.965），91.3%（95% CI：0.797–0。966) 的阴性预测值 (NPV) 和 66.7% (95% CI: 0.544–0.771) 的特异性。小囊肿的特异性为 100% (95% CI: 0.941-1)，PPV 为 100% (95% CI: 0.816-1)，敏感性为 37.8% (95% CI: 0.251–0.524)。粗糙隔膜的敏感性为 100% (95% CI: 0.943-1)，PPV 为 100% (95% CI: 0.796-1)，特异性为 33.3% (95% CI: 0.211–0.478)。结 3% (95% CI: 0.211–0.478) 的特异性。结 3% (95% CI: 0.211–0.478) 的特异性。结