Chest radiography and CT of fibrosing alveolitis

Abstract

•. In established fibrosing alveolitis, there is a reticulo‐nodular pattern most marked at the bases on chest radiography; patchy or diffuse ground glass opacification is a less common finding. •. High resolution CT accurately depicts the macroscopic appearances of CFA. A basal subpleural reticular pattern admixed with areas of apparently normal lung is typical; there may be ground glass opacification, tractional dilatation of airways and honeycombing. •. In CFA the interpretation of ground glass opacification on HRCT is not straightforward. The relative proportions, rather than the absolute severity of fibrosis and cellularity are important determinants of likely response to treatment and prognosis. •. Data on the HRCT features of (biopsy confirmed) desquamative interstitial pneumonitis (DIP) and non‐specific interstitial pneumonitis (NSIP) are limited. Patchy areas of ground glass opacification are typically seen in DIP; there is a lower zone predominance in the majority of patients but a subpleural distribution is documented in just over half. Ground glass opacification is also a dominant CT finding in NSIP but, in general, the CT appearances are inconsistent.