[A high-resolution CT and pathological study of nonspecific interstitial pneumonia]

To describe the characteristics of high-resolution CT(HRCT) findings of nonspecific interstitial pneumonia (NSIP) and the correlation with pathological changes.

The HRCT features of 9 cases (3 men and 6 women) of histopathologically confirmed NSIP were retrospectively analyzed and correlated with the pathological findings.

The predominant HRCT features, found in all the cases, were bilaterally patchy areas of ground-glass opacity with or without areas of consolidation. Irregular linear opacities, traction bronchiectasis, and thickening of bronchovascular bundles were also frequently seen. The abnormalities were distributed over the peripheral zones of the middle and lower lungs in most cases. Honeycombing was not a feature in all the cases. Areas of ground-glass opacity with or without irregular linear opacity or traction bronchiectasis corresponded pathologically to areas of interstitial thickening caused by varying degrees of interstitial inflammation and fibrosis showing temporal uniformity. Areas of consolidation were associated with extensive collagen-type interstitial fibrosis and mild interstitial inflammation at the biopsy sites, and occasionally represented the areas of bronchiolitis obliterans organizing pneumonia, foamy cell collections in alveolar spaces, or microscopic honeycombing with mucin stasis.

The HRCT manifestations of NSIP are characteristic though not specific. In patients with consistent clinical features, the diagnosis of NSIP can be suspected by typical HRCT findings.