[Plain film and CT findings of pulmonary involvement in rheumatoid arthritis]

To analyze the plain film and CT findings of rheumatoid arthritis (RA)-associated lung diseases and to correlate them with clinical manifestations.

We retrospectively reviewed the plain chest and CT findings of 51 RA patients with lung diseases. Sixteen CT findings were separately corded as present or absent, and drew up our classification of lung diseases as follows; 1. interstitial pneumonia/pulmonary fibrosis (IP/PF), 2. airway disease (AD), 3. parenchymal disease (PD), and 4. mixed. Four plain film findings were also recorded, and classified in IP/PF or AD group. This classification was analyzed with reference to clinical parameters and courses.

Fifty-one patients were classified as follows; 1. IP/PF (n = 32, 62.6%), 2. AD (n = 15, 29.4%), 3. PD (n = 3, 5.9%), 4. mixed (n = 1, 2.0%). CT findings of PD were compatible with bronchiolitis obliterans organizing pneumonia with rapid improvement. IP/PF diagnosed with CT was depicted by the plain chest in 25 patients (78.1%). There is no false positive of the plain chest diagnosis in terms of IP/PF. As compared with IP/PF, AD consisted of significantly higher prevalence in female patients and patients with severe articular involvement and sinusitis. In spite of variable outcome in patients with AD, those with IP/PF showed the progression of honeycombing, and 4 of them were died from respiratory failure.

CT based classification of rheumatoid lung diseases correlates with clinical manifestations and prognosis and is useful for clinical management in patients of RA. CT diagnosis is useful especially when plain chest does not demonstrate typical IP/PF pattern.