High-resolution computed tomography (HRCT) is a diagnostic method for assessing the lungs but more specifically the interstitium of the lungs. The technique involves obtaining narrow cross-sectional slices of 1 to 2 mm. These scans enable the physician and radiologist to view the patterns of disease and their distribution. Diseases that may be easily demonstrated using this procedure include emphysema (Fig. 3.52), pneumoconiosis (coal worker’s pneumoconiosis), and asbestosis. HRCT is also useful in regular follow-ups of patients with interstitial disease to monitor disease progression.