Case studies on the role of computerized tomography pulmonary angiography in improving clinical diagnosis of invasive pulmonary aspergillosis

Invasive pulmonary aspergillosis (IPA) is a severe infection that occurs in patients with hematological malignancies during their treatment. The limited specificity of computerized tomography (CT) imaging and non-culture-based biomarkers may lead to excessive use of antifungal drugs in patients. CT pulmonary angiography (CTPA) is a supplementary noninvasive method to CT that can directly visualize the pulmonary arteries within the infiltrated areas of the lungs to observe signs of vascular invasion and obstruction. Four cases of hematological malignancies were reported, in which patients developed fever during the treatment. All patients underwent CTPA examination, which showed positive vascular occlusion sign (VOS) in two patients, and negative VOS in the other two. Two patients with positive VOS were diagnosed as probable IPA and possible IPA respectively. Both of them received antifungal treatment and their conditions improved. Of the two VOS-negative patients, one was diagnosed with diffuse large B-cell lymphoma involving the lung and the other one was considered to have possible pulmonary infiltration of leukemia. After receiving treatment for lymphoma and leukemia, respectively, two patients showed significant reduction in pulmonary lesions. Therefore, VOS detected by CTPA has certain characteristics, which can help improve diagnostic specificity and guide clinical treatment for patients with IPA.