title: Thin-section CT assessment of spontaneous pneumomediastinum in interstitial lung disease: correlation with serial changes in lung parenchymal abnormalities.
abstract: OBJECTIVE
  The 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.
  
  
  METHODS
  We 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.
  
  
  RESULTS
  The mean score of all patients for honeycombing significantly increased at the time of detection of pneumomediastinum (P=0.003). In group 1, the extent of increasing opacity had been decreased significantly at the time of detection of pneumomediastinum (P=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=0.028, 0.018, and 0.018, respectively).
  
  
  CONCLUSIONS
  Spontaneous pneumomediastinum associated with interstitial lung disease appears to have a tendency to occur under conditions of altered of parenchymal interstitial lesions.
authors.affiliation: Department of Radiology, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-Ku, Kawasaki City, Kanagawa 216-8511, Japan. shinma@d9.dion.ne.jp
authors.forename: Shin
authors.initials: S
authors.lastname: Matsuoka
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Kurihara
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Yagihashi
authors.forename: Kyoko
authors.initials: K
authors.lastname: Okamoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Niimi
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Nakajima
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002543:Cerebral Hemorrhage; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D017563:Lung Diseases, Interstitial / Q000150:complications / Q000000981:diagnostic imaging* / Q000188:drug therapy; D008297:Male; D008478:Mediastinal Emphysema / Q000000981:diagnostic imaging* / Q000209:etiology; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D000305:Adrenal Cortex Hormones; D007166:Immunosuppressive Agents