Comparison of Lung Masses Perfusion Characteristics by Dynamic Contrast Enhanced CT with Histopathology: A Cross-sectional Study

Introduction: The management of lung masses depends upon the nature of the mass i.e., being benign or malignant. The use of contrast based Computed Tomography (CT) scan helps in ascertaining the malignant nature of the lesion. In previous studies, computed tomographic evaluations are done to evaluate pulmonary nodules, but only few studies characterised the lung masses into benign and malignant lesions. Aim: To evaluate the diagnostic accuracy of a non invasive modality (dynamic contrast enhanced perfusion CT), in the characterisation of lung masses by comparing with histopathology. Materials and Methods: A cross-sectional observational study was conducted at a tertiary care centre, Lucknow, Uttar Pradesh, India from January 2018 to November 2019 where 62 patients between age group 20-80 years of both sexes with lung masses and no contraindications to the administration of iodinated contrast material were enrolled in the study. Dynamic Contrast Enhanced CT (DCE-CT) perfusion was done which included parameters like Blood Flow (BF) in mL/100 g/min, Blood Volume (BV) in mL/100 g, Mean Transit Time (MTT) in seconds, and Flow Extraction Product (FEP) in mL/100 mL/min. The DCE-CT features were compared with histopathology to determine the sensitivity, specificity, Positive Predictive Value (PPV), and Negative Predictive Value (NPV). Results: Among the 62 lung mass cases included in the study, 30 were histopathologically found to be benign lesions and 32 were malignant lesions. On contrast enhancement, the values of the CT perfusion parameters among the malignant masses were significantly higher as compared to benign (p<0.001). DCE- CT was able to correctly diagnose 31/32 cases of malignant and 26/30 cases of benign lung masses in concordance with histopathology. Thus, the overall, sensitivity, specificity, PPV, NPV, and diagnostic accuracy was 96.90%, 86.70%, 88.60%, 96.30%, and 91.90%, respectively. Conclusion: The DCE-CT has a high diagnostic value in differentiation of malignant from benign lung masses and thus can be promoted for its use as a non invasive methods for lung masses characterisation.