ObjectiveTo explore the differential diagnosis value of subpleural bandlike ground-glass opacity (GGO) in thoracic CT in paraquat poisoning pneumonia. MethodsA retrospective study was carried out by retrieving the patients CT database from March 2013 to March 2015. The patients with paraquat poisoning pneumonia, interstitial pneumonia and pulmonary alveolar proteinosis (PAP) were recruited and their radiological characteristics of thoracic CT were analyzed. ResultsA total of 698 newly diagnosed interstitial pneumonia patients were finally enrolled in this study, 392 of them (56.2%) presented with GGO in thoracic CT. A total of 38 newly diagnosed PAP patients and 14 paraquat poisoning patients were enrolled, and GGO presented in thoracic CT of 100.0% and 42.9% of them respectively. Subpleural bandlike GGO was mostly commonly found in 83.3% of the paraquat poisoning pneumonia patients with GGO in thoracic CT, followed by 18.4% of the PAP patiens and 5.6% of the interstitial pneumonia patients with GGO in thoracic CT, which were significantly lower than that in the paraquat poisoning pneumonia patients (P < 05). GGO associated crazy paving pattern in thoracic CT was mostly commonly found in 94.7% of the PAP patients, followed by 0.5% of the interstitial pneumonia patients and none of the paraquat poisoning pneumonia patients. All the PAP patients with subpleural bandlike GGO were found associated with crazy paving pattern, while none of such association was found in the interstitial pneumonia or the paraquat poisoning pnuemonia patients. GGO coexisting with honeycombing and subpleural line were respectively found in 22.7% and 11.2% of the interstitial pneumonia patients, and none of such association was found in the PAP or the paraquat poisoning pneumonia patients. ConclusionsSubpleural bandlike GGO is mostly commonly found in paraquat poisoning pneumonia patients and rarely in PAP and interstitial pneumonia patients. Combined with crazy paving pattern and subpleural line, subpleural bandlike GGO may be a valuable feature in the diagnosis of paraquat poisoning pneumonia patients.