Pulmonary alveolar proteinosis : High-resolution CT, chest radiographic, and functional correlations

To determine whether a correlation exists between pulmonary function and both frontal chest radiographs and high-resolution chest CT findings in patients with pulmonary alveolar proteinosis (PAP). Retrospective review of radiographic and clinical data. Tertiary referral hospital. Seven patients with PAP were studied on 25 occasions using high-resolution chest CT (n=21), frontal chest radiographs (n=19), and pulmonary function tests (PFTs) (n=25). Visual estimates of the extent, degree, and overall severity of parenchymal abnormalities were determined for plain radiographs and high-resolution chest CT, and were correlated with PFTs. With high-resolution CT, the extent and severity of ground-glass opacity correlated significantly with the presence of a restrictive ventilatory defect, reduced diffusing capacity, and hypoxemia. Chest radiographic findings also correlated significantly with restrictive ventilatory defect, diffusing capacity, and hypoxemia. In patients with PAP, although high-resolution CT correlates more closely with pulmonary function, plain radiographs should be sufficient for follow-up.