Role of high resolution computed tomography in evaluation of diffuse lung diseases

Background: Diffuse lung diseases are those in which the disease process is widespread involving both the lungs but need not affect all lung regions uniformly. Plain chest radiograph though inexpensive, excellent modality of choice, the pattern of diffuse lung disease on radiography is often nonspecific. HRCT can detect normal and abnormal lung interstitium and morphological characteristics of both localized and diffuse lung diseases. The aims and objectives was to study the normal anatomy of the lung with respect to secondary pulmonary lobule; to evaluate the importance of high resolution computed tomography in the diagnosis of diffuse lung diseases; to detect diffuse lung diseases in patients who had normal or questionable radiographic abnormalities with symptoms or pulmonary function tests suggestive of diffuse lung disease; to determine the site of CT guided lung biopsy for confirmation of diagnosis in suspicious diseases and to study the various patterns of diffuse lung diseases on HRCT.Methods: A total number of 50 patients with suspected or known interstitial lung disease were studied by high-resolution computed tomography (HRCT) over a period of 24 months.Results: In the current study the most common cases are of tuberculosis. Next common condition observed was idiopathic pulmonary fibrosis,12 (24%) cases out of 50 cases and most of them were having changes of end stage lung disease and had short lived history during the course of this study, followed by bronchiectasis, pulmonary edema and emphysema.Conclusions: HRCT is 16% more sensitive in detection of diffuse lung disease abnormalities than chest radiograph in our study.