High-definition computed tomography in the study of the pulmonary parenchyma. The author's own experience]

High-resolution CT (HRCT) scans were performed on 156 patients, using a bone-reconstruction algorithm, 1.5 collimation at 4 cm intervals from apex to base of the lungs and a 512 x 512 matrix. The patients appeared to have a pathologic condition on chest film, or else they presented positive clinical symptoms--i.e., cough, dyspnea, fever--and questionable/negative chest films. Since HRCT is capable of showing the secondary lobule, we employed it to study both its anatomy and the alterations that can modify its normal morphology--i.e., thickening of interlobular septa, reticular pattern, nodular pattern, high-density areas, sub-pleural lines, honeycomb pattern. HRCT findings in secondary lobules, airways, and pleura were examined. They were: lymphangitic spread of carcinoma, pulmonary fibrosis, sarcoidosis, pneumoconiosis, interstitial edema, phlogosis, bronchiectasis, emphysema, and bullae. Even though some limitations still exist due to the aspecificity of HRCT findings, the latter is the best method currently available to recognize and locate interstitial conditions and, sometimes, to make a diagnosis--e.g., of lymphangitic spread of carcinoma, interstitial edema, fibrosis, emphysema, bronchiectasis. Moreover, HRCT can accurately locate pathologic areas for lung biopsy and can be used instead of chest radiographs in the follow-up.