Usefulness of tissue permeability factor in differentiating benign and malignant pulmonary lesions on dynamic contrast-enhanced MIRI

To evaluate the clinical usefulness of tissue permeability factor in differentiating benign and malignant pulmonary lesions on dynamic contrast-enhanced (DCE) MRI. 30 patients (14 women, 16 men; median age, 64 years; age range, 41-80 years) who had a pulmonary lesion underwent DCE MR imaging at 3.0 T. Fifteen patients had lung cancer and 15 patients had benign pulmonary nodules. To calculate the perfusion parameters of the pulmonary lesions, quantitative analysis was carried out on all 30 pulmonary nodules or masses: volume transfer constant (Ktrans), reflux constant (Kep), and extravascular extracellular space volume fraction (ve). A Mann-Whitney test was used to calculate the statistical significance of quantitative perfusion parameters between malignant and benign pulmonary lesions. Receiver operating characteristic curve analysis was also performed for evaluation of sensitivity and specificity of perfusion parameters to diagnose lung cancer. Malignant pulmonary lesions had higher Ktrans and ve values than benign pulmonary lesions (0.227 ± 0.065 vs. 0.133 ± 0.054; p = 0.001, 0.479 ± 0.156 vs. 0.357 ± 0.13; p = 0.038, respectively). However, the difference in Kep between the benign and malignant pulmonary lesion was not significant (0.648 ± 0.44 vs. 0.797 ± 0.93; p = 0.709). With a threshold of 0.202 (min-1), the sensitivity and specificity to diagnose malignant pulmonary lesions of the Ktrans value were 66.6% and 93.3%, respectively. Ktrans and ve value of perfusion parameters on DCE-MRI can help to discriminate between malignant and benign pulmonary nodules or masses.