Diagnostic Accuracy of Dynamic Contrast Enhanced Magnetic Resonance Imaging in Characterizing Lung Masses

Background: Imaging plays a critical role not only in the detection, but also in the characterization of lung masses as benign or malignant. Objectives: To determine the diagnostic accuracy of dynamic magnetic resonance imaging (MRI) in the dierential diagnosis of benign and malignant lung masses. PatientsandMethods: Ninety-four masses were included in this prospective study. Five dynamic series of T1-weighted spoiled gra- dient echo (FFE) images were obtained, followed by a T1-weighted FFE sequence in the late phase (5th minutes). Contrast enhance- ment patterns in the early (25th second) and late (5th minute) phase images were evaluated. For the quantitative evaluation, signal intensity (SI)-time curves were obtained and the maximum relative enhancement, wash-in rate, and time-to-peak enhancement of masses in both groups were calculated. Results: The early phase contrast enhancement patterns were homogeneous in 78.2% of the benign masses, while heterogeneous in 74.4% of the malignant tumors. On the late phase images, 70.8% of the benign masses showed homogeneous enhancement, while most of the malignant masses showed heterogeneous enhancement (82.4%). During the first pass, the maximum relative enhancement and wash-in rate values of malignant masses were significantly higher than those of the benign masses (P = 0.03 and 0.04, respectively). The cuto value at 15% yielded a sensitivity of 85.4%, specificity of 61.2%, and positive predictive value of 68.7% for the maximum relative enhancement. Conclusion: Contrast enhancement patterns and SI-time curve analysis of MRI are helpful in the dierential diagnosis of benign