Discrimination between Benign and Malignant Lung Lesions using Volumetric Quantitative Dynamic Contrast-enhanced MRI

Abstract

Background: Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is considered a promising method in lung lesion assessment. Methods: Sixty-four patients with single pulmonary lesions (SPLs) received DCE-MRI at 3.0 T. Of them, 49 cases were diagnosed with lung cancer, and 15 with benign pulmonary nodules (8 inflammatory nodules, 5 tuberculosis, and 2 abscesses). SPLs were quantitatively analyzed to determine the pulmonary lesions-related perfusion parameters, including reflux constant (Kep), volume transfer constant (Ktrans), the maximum slope of increase (MaxSlope), extravascular extracellular space volume fraction (Ve), apparent diffusion coefficient (ADC), the initial area in the signal intensity-time curve (IAUGC), and contrast-enhancement ratio (CER). In addition, a Student’s t-test was conducted to calculate statistical significance regarding the quantitatively analyzed perfusion parameters in benign SPLs compared to malignant SPLs. The area under (AUC) the receiver operating characteristic (ROC) curve was studied to investigate the performance of perfusion parameters in diagnosing lung cancer. Results: Values of Ktrans, Kep, Ve, MaxSlope, and IAUGC increased within malignant nodules relative to benign nodules (Ktrans: 0.21 ±0.08 vs. 0.73 ±0.40, P = 0.0001; Kep: 1.21 ±0.66 vs. 1.83 ±0.90, P = 0.0163; Ve: 0.24 ±0.08 vs. 0.47 ±0.18, P < 0.0001; MaxSlope: 0.09 ±0.14 vs. 0.28 ±0.29, P = 0.0166; IAUGC: 0.18 ±0.09 vs. 0.55 ±0.34, P = 0.0001). Meanwhile, malignant nodules presented higher ADC than benign nodules (0.0016 ±0.0006 vs. 0.0012 ±0.0003, P = 0.0019). Ktrans and IAUGC showed the best diagnostic performance with AUCs [1.0, 95%CI (0.99–1.0); 0.93, 95%CI(0.85–1.0), respectively]. Conclusion: Malignant pulmonary lesions had higher values of Ktrans, Ve, Kep, MaxSlope, and IAUGC compared to benign pulmonary lesions. Overall, perfusion parameters of DCE-MRI facilitate discrimination between benign from malignant pulmonary nodules.