Abstract : High Resolution Computed Tomography is a non-invasive technique for evaluating patients with clinically diagnosed Connective Tissue Disorders and plays an important role in detecting early morphologic changes in patients with suspected pulmonary disorders such as interstitial lung disease and bronchiectasis. Aims of this study were to evaluate the High Resolution Computed Tomography thorax findings and identify specific patterns of involvement in different connective tissue disorders The study was done as a hospital based cross sectional descriptive study comprised of 60 consecutive patients who were clinically diagnosed with a connective tissue disorder from April 2018 to March 2019 for a period of 12 months in the Department of Radiodiagnosis, Gauhati Medical College and Hospital, Guwahati. Graphpad instat 3 software and paired t test were used in the calculation. Most common Interstitial lung disease pattern was Nonspecific Interstitial Pneumonia (33%), followed by Usual Interstitial Pneumonia (16.7%) pattern. But significantly higher incidence of Usual Interstitial Pneumonia pattern and bronchectatic changes was noted in Rheumatoid Arthritis as compared to other Connective Tissue Disorders (p values 0.0016 and 0.0148 respectively). There is significantly high percentage of pleural effusion in patients presenting with Systemic Lupus Erythematosus (p value 0.0044). There is also significantly higher occurrence of esophageal dilatation in patients with Systemic Sclerosis (p value 0.0001). High Resolution Computed Tomography evaluation is of immense importance and utility in understanding the extent and type of pulmonary involvement and in distinguishing the pattern of interstitial lung disease in different Connective Tissue Disorders.

Keyword : Key words: Interstitial lung disease, Connective Tissue Disorders, High Resolution Computed Tomography, Usual Interstitial pneumonia, Nonspecific Interstitial pneumonia.