Pulmonary involvement in mixed connective tissue disease: comparison with other collagen vascular diseases using high resolution CT.

Purpose: The purpose of this work was to compare the CT findings of lung involvement in patients with mixed connective tissue disease (MCTD) with those in patients with other CTDs: systemic lupus erythematosus (SLE), systemic sclerosis (SSc), and polymyositis and dermatomyositis (PM-DM).
Method: CT scans of 35 patients with interstitial lung disease and associated MCTD were evaluated retrospectively. The CT assessment included determination of the findings and evaluation of whether the findings in MCTD were different from those in other CTDs.
Results: The frequency of ground-glass opacity in MCTD was significantly lower than in CTDs (p < 0.05). The frequency of honeycombing in MCTD was lower than in SSc (p < 0.05) and higher than in PM-DM (p < 0.005). Regarding the predominant CT patterns, the frequency of septal thickening in MCTD was significantly higher than in CTDs (p < 0.05).
Conclusion: CT findings in MCTD were a combination of those in other CTDs.