Features of Computed Tomography Perfusion of Mediastinal Lymphadenopathies: a Pathology-based Retrospective Study

Objective To explore the features of various mediastinal lymphadenopathies using computed tomography perfusion (CTP). Methods CTP parameters (CTPs) of the selected mediastinal nodes from 59 patients with pathology-proven malignant lymph nodes and of those from 29 patients with clinically diagnosed or pathology-proven inflammatory lymphadenopathies were collected. Patients were divided into subgroups by etiology and phase of primary disease, including different pathological malignant nodes and diverse inflammatory nodes. CTPs were defined as blood flow (BF), blood volume (BV), mean transit time (MTT), permeability (PMB), and time to peak (TTP). Differences of CTPs were compared between malignant and benign nodes, and among subgroups, respectively. Results In the mediastinum, no significant differences of CTPs were found between malignant and benign groups (all P>0.05), the same for subgroups of malignant nodes (all P>0.05). Acute lymphadenitis had higher BF and BV than chronic inflammatory, lymphoid tuberculosis, sarcoidosis and malignant nodes. The BF of malignant nodes was markedly slower than that of acute lymphadenitis (P=0.01), but faster than chronic inflammatory nodes (P=0.04) and sarcoidosis (P=0.03), with no significant difference compared with lymphoid tuberculosis. Pneumonia-complicated lymphoid tuberculosis showed the longest MTT while sarcoidosis displayed the shortest MTT, and inflammatory nodes, lymphoid tuberculosis without complicated pneumonia and malignant nodes had moderate MTT. Conclusion CTPs show promising potential in distinguishing various lymphadenopathies in the mediastinum, but more studies are needed to improve their specificity.