Hoon Y, et al. - This study was conducted to evaluate CT imaging features associated with poor clinical outcome after corticosteroid treatment in individuals diagnosed with cryptogenic organizing pneumonia (COP) and connective tissue disease-related organizing pneumonia (CTD-OP) and to evaluate the difference in CT findings and treatment responses between COP and CTD-OP. Two thoracic radiologists reviewed chest CT images from 166 individuals (COP, 131; CTD-OP, 35) with pathologically proven organizing pneumonia. For each individual, the type, distribution pattern, and extent of parenchymal abnormalities, along with other associated imaging features, were evaluated. Researchers applied Logistic regression analyses to distinguish features correlated with poor clinical outcomes such as residual disease (RD) and disease relapse. The variations between COP and CTD-OP were also examined. Bronchiectasis and a greater extent of consolidation were correlated with RD, with the latter also being linked with disease relapse. In Comparison with cryptogenic organizing pneumonia, CTD-OP was linked with worse treatment results and showed a greater extent of parenchymal abnormalities, which were also less likely to give a peribronchovascular pattern.