Hypersensitivity pneumonitis: evaluation with CT.

Abstract

Thirteen chest radiographs and computed tomographic (CT) scans obtained from 11 patients with hypersensitivity pneumonitis were reviewed. The CT findings were correlated with open lung biopsy findings in seven patients. The two patients with acute hypersensitivity pneumonitis showed air-space opacification on CT scans. An open lung biopsy, done in one of these patients, demonstrated noncaseating granulomas and filling of the air spaces with macrophages. The nine patients with subacute hypersensitivity pneumonitis showed small, rounded opacities and patchy air-space opacification on CT scans. These findings reflected the histologic findings, which consisted of interstitial pneumonitis, cellular bronchiolitis, and small, noncaseating granulomas. The six patients with symptoms for 12 months or longer also showed irregular linear opacities on CT scans, corresponding to areas of fibrosis. CT scans were superior to radiographs in helping to assess the type and extent of abnormalities, and high-resolution CT scans were superior to conventional CT scans.

Summer-type hypersensitivity pneumonitis: comparison of high-resolution CT and plain radiographic findings.

“…Diffuse micronodules remained even after clinical improvement. The micronodular opacities probably reflect cellular bronchiolitis and granulomas [5]. Slightly increased lung density may reflect diffuse interstitial infiltrates of chronic inflammatory cells and granulomas.…”

“…In the acute stage, the CT findings were nonspecific air-space opacification. In the subacute stage, they included small, rounded opacities and patchy, soft air-space opacification that did not obscure underlying interstitial markings [5]. The CT appearance of summer-type hypersensitivity pneumonitis depended on the time during the course of the disease at which the scans were made.…”

High-resolution computed tomographic characteristics in acute farmer's lung and in its follow-up

“…More importantly, HRCT will yield a much more precise description of the underlying abnormalities allowing better understanding of the disease process. In active disease typical HRCT shows diffuse micronodules and patchy ground-glass attenuation [6,7]. These typical findings are very useful in the differential diagnosis of HP from other causes of interstitial diseases; in one study computed tomography (CT) allowed correct distinction of HP from idiopathic pulmonary fibrosis in 90% of cases [9].…”

“…The findings of HRCT in HP have been described [6±10]. In both acute and chronic HP, HRCT can help distinguish this disease from other interstitial lung diseases [6,11]. Being more sensitive than standard chest radiographs, HRCT will identify abnormalities where none were seen on posterioanterior and lateral chest films [12].…”

Hypersensitivity Pneumonitis Caused by Oyster Mushrooms: A Case of Mushroom Worker's Lung

“…Then, high-resolution CT is performed (17). Although CT findings in patients with HP are often nonspecific, diagnosis can be confirmed without biopsy in patients with a characteristic appearance (18). The most common radiological findings in HP are ground-glass opacities and micronodules in the subacute form of the disease, and air-trapping in expiratory studies (19).…”