Differential diagnosis of infectious diseases, drug-induced lung injury, and pulmonary infiltration due to underlying malignancy in patients with hematological malignancy using HRCT

Purpose To differentiate among infectious diseases, drug-induced lung injury (DILI) and pulmonary infiltration due to underlying malignancy (PIUM) based on high-resolution computed tomographic (HRCT) findings from patients with hematological malignancies who underwent chemotherapy or hematopoietic stem cell transplantation. Materials and methods A total of 221 immunocompromised patients with hematological malignancies who had proven chest complications (141 patients with infectious diseases, 24 with DILI and 56 with PIUM) were included. Two chest radiologists evaluated the HRCT findings, including ground-glass opacity, consolidation, nodules, and thickening of bronchovascular bundles (BVBs) and interlobular septa (ILS). After comparing these CT findings among the three groups using the χ 2 test, multiple logistic regression analyses (infectious vs noninfectious diseases, DILI vs non-DILI, and PIUM vs non-PIUM) were performed to detect useful indicators for differentiation. Results Significant differences were detected in many HRCT findings by the χ 2 test. The results from the multiple logistic regression analyses identified several indicators: nodules without a perilymphatic distribution [ p = 0.012, odds ratio (95% confidence interval): 4.464 (1.355–11.904)], nodules with a tree-in-bud pattern [ p = 0.011, 8.364 (1.637–42.741)], and the absence of ILS thickening[ p = 0.003, 3.621 (1.565–8.381)] for infectious diseases, the presence of ILS thickening [ p = 0.001, 7.166 (2.343–21.915)] for DILI, and nodules with a perilymphatic distribution [ p = 0.011, 4.256 (1.397–12.961)] and lymph node enlargement ( p = 0.008, 3.420 (1.385–8.441)] for PIUM. Conclusion ILS thickening, nodules with a perilymphatic distribution, tree-in-bud pattern, and lymph node enlargement could be useful indicators for differentiating among infectious diseases, DILI, and PIUM in patients with hematological malignancies.