Objectives: We investigated the prediction of outcomes of patients with dermatomyositis with acute/subacute interstitial pneumonia (DM-A/SIP) on the basis of chest computed tomography (CT) images.
Methods: In 20 patients with DM-A/SIP (13 survivors; seven deaths), the relationships between prognostic outcomes and chest high-resolution CT (HRCT) findings or limited three-level thin-section CT scoring on the first examination were retrospectively investigated.
Results: No significant difference was noted in chest HRCT findings between the survivor group and death group. The ground-glass opacity (GGO) scores of the right upper and middle lobes and left upper lobe, and the fibrosis score of the right middle lobe were significantly higher in the death group than in the survivor group (p = 0.01, 0.001, 0.02, and 0.02, respectively). The influence of the GGO score of the right middle lobe on death from IP was the strongest among the items examined, and it was independently significant (p = 0.01). A right middle lobe GGO score of ≥3 (GGO ≥ 25% of the lobe) was determined to be the best cut-off value for a poor prognosis (sensitivity: 85.7%, specificity: 85.7%), and the survival rate after 24 weeks was significantly lower in patients with a right middle lobe GGO score of ≥3 (survival rate: 0.0%) than in those with a score of< 3 (92.9%) (p < 0.0001).
Conclusions: The prognosis of patients with DM-A/SIP was poor when the range of right middle lobe GGO was 25% or higher on limited three-level thin-section CT.
Keywords: CT scoring; Chest CT; Dermatomyositis; Interstitial pneumonia; Prognosis.