Intravoxel incoherent motion diffusion-weighted MR imaging in differentiation of lung cancer from obstructive lung consolidation: comparison and correlation with pharmacokinetic analysis from dynamic contrast-enhanced MR imaging.

Abstract

To test whether parameters derived from intravoxel incoherent motion (IVIM) can be used to distinguish lung cancer from obstructive pulmonary consolidation by comparing them with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI)-derived parameters and to evaluate the correlation between these quantitative parameters. A total of 31 lung cancer patients, confirmed by pathology and obstructive consolidations confirmed by positron emission tomography/computed tomography (PET-CT), were recruited. All of them were assessed with structural MRI and IVIM and 17 of them underwent additional DCE-MRI examinations. Parameters derived from IVIM and DCE-MRI in the tumour and consolidation were analysed, and the optimal cut-off values in differential diagnosis were obtained. ADC(total), D and f values were lower (P < 0.05), while IAUC60 was higher in lung cancers (P = 0.013) compared with obstructive pulmonary consolidations. According to the ROC curve, ADC(total) outperformed other perfusion and diffusion parameters with the optimal cut-off value of 1.409 × 10(-3) mm(2)/s (AUC = 0.95). Poor correlations were found between parameters derived from IVIM and DCE-MRI. IVIM-MRI is potentially useful in the differentiation of lung cancer and obstructive pulmonary consolidation. ADC(total), D and f may be reliable independent discriminating markers, but D* is variable with low diagnostic accuracy. • Lung cancer and consolidation differentiation is essential for treatment decision-making. • Perfusion and diffusion characteristics of lesions could help differential diagnosis. • IVIM can separate reflection of tissue diffusivity and microcapillary perfusion. • The relationship between perfusion quantified by IVIM and DCE-MRI is controversial.