Thin-section CT assessment of spontaneous pneumomediastinum in interstitial lung disease: Correlation with serial changes in lung parenchymal abnormalities

SummaryPurposeThe purpose of this study was to analyze thin-section computed tomography (CT) appearances of interstitial lung diseases before and at the time of detection of pneumomediastinum, and to evaluate the relationship between pneumomediastinum and parenchymal changes on thin-section CT.Materials & methodsWe reviewed CT images before and at the time of detection of pneumomediastinum in 13 patients with idiopathic pulmonary fibrosis (8 patients) and collagen vascular diseases (5 patient). The extent of the total area of reticular opacity, increased opacity (ground-glass opacity and consolidation), and honeycombing were scored, and these scores were compared before and at the time of detection of pneumomediastinum. We also divided patients into two groups according to therapy received. Patients in group 1 experienced pneumomediastinum after or during treatment with corticosteroids or immunosuppressive agents for acute or subacute exacerbation of interstitial lung disease. Patients in group 2 experienced pneumomediastinum without therapy.ResultsThe mean score of all patients for honeycombing significantly increased at the time of detection of pneumomediastinum (P=0.003P=0.003). In group 1, the extent of increasing opacity had been decreased significantly at the time of detection of pneumomediastinum (P=0.028P=0.028). In group 2, the mean CT score of reticular opacity, increasing opacity, and honeycombing significantly increased at the time of detection of pneumomediastinum (P=0.028P=0.028, 0.018, and 0.018, respectively).ConclusionsSpontaneous pneumomediastinum associated with interstitial lung disease appears to have a tendency to occur under conditions of altered of parenchymal interstitial lesions.