Chest CT in bronchopulmonary dysplasia: clinical and radiological correlations

Chest CT is very sensitive in assessing pulmonary damage in bronchopulmonary dysplasia (BPD) and radiological findings in BPD are well described. Validated CT scores are available to assess BPD, as available in other pulmonary diseases such as cystic fibrosis.

To investigate whether there is a correlation between radiological pulmonary lesions and relevant BPD clinical data (gestational age, type and duration of mechanical ventilation, and severity of BPD) and assess the usefulness of a CT score in evaluating clinical severity.

Retrospective study of 19 premature infants with BPD born between 1998 and 2007 who underwent at least one chest CT during their first year of life. A total of 29 CT were blindly evaluated by two radiologists for the presence or absence of pulmonary parenchymal abnormalities described in BPD (areas of decreased attenuation, presence of bullae/emphysema, bronchial wall thickening, bronchiectasis, linear, and subpleural opacities). This score was then compared with the most relevant clinical data.

All CT scans showed abnormalities. The most frequent lesion was bronchial wall thickening observed in all patients, followed by linear (89.5%) and subpleural (89.5%) opacities. Areas of decreased attenuation were found in 68.4%. Bullae/emphysema and bronchiectasis were the less frequent item described (26.3% and 21.1%, respectively). The presence of areas of decreased attenuation significantly correlated with BPD severity (P = 0.03). However, there was no significant correlation between the CT score and clinical data.

This study demonstrates the potential usefulness of chest CT score to assess the severity of BPD. Areas of decreased attenuation seem the most sensitive item to predict BPD severity. More patients are needed to validate this approach and to evaluate the long-term usefulness of CT scan.