[CT of hypersensitivity pneumonitis]

High resolution computed tomography (CT) was applied to seven patients with hypersensitivity pneumonitis clinically confirmed. The CT findings include; (1) granular pattern with acino-centric distribution, (2) increase in density of haziness in the lung fields, (3) multiform high density areas, and (4) "subpleural curvilinear shadow" localized posteriorly. Of these findings, which severally varied degree during clinical course, the haziness showed the most remarkable fluctuation. It was especially of interest that the relapsed haziness distributed quite in the same regions. High resolution CT may be an effective adjuvant tool for hypersensitivity pneumonitis when applied to the opportune evaluation through the clinical course.