Diagnosis of solitary pulmonary lesions with intravoxel incoherent motion diffusion-weighted MRI and semi-quantitative dynamic contrast-enhanced MRI

AIM: To evaluate the diagnostic value of intravoxel incoherent motion (IVIM) diffusion-weighted (DWI) magnetic resonance imaging (MRI) and semi-quantitative dynamic contrast-enhanced MRI (DCE-MRI) to help diagnose indeterminate solitary pulmonary lesions (SPLs) and the subgroups of lung cancer (LC), and to explore the relationship between IVIM and DCE-MRI. MATERIALS AND METHODS: Sixty-four consecutive patients (44 male, 20 female; age, 52.77 +/- 10.46 years) from February 2014 to September 2016 with SPLs, were involved in this prospective study. Total apparent diffusion coefficient (ADCtotal), tissue diffusivity (D), pseudo-diffusion coefficient (D*), perfusion fraction (F), maximum enhancement ratio (MER), Tmax, slope, and washout were compared between the lung cancer (LC) and benign group and among the subtypes of LC. Time-intensity curves (TICS) were drawn. Receiver operating characteristic (ROC) curves were constructed to estimate the diagnostic performance. The correlation of both tools was assessed. RESULTS: ADCtotal, D, and Tmax were significantly higher for benignity than for LC (p=0.005, p=0.002 and p<0.001 respectively). D* and slope were significantly higher in LC than benignity (p=0.005 and p=0.011, respectively). D and Tmax had the highest sensitivity and accuracy, respectively. A combination of D and Tmax improved the sensitivity to 90.5%, the specificity to 86.4%, and the accuracy to 89.1%. Poor correlations were found between parameters derived from IVIM and DCE-MRI. ADCtotal values of SCC and SCLC were found to be significantly lower compared with that in adenocarcinoma. CONCLUSION: Both IVIM-DWI and DCE-MRI were useful for discriminating benignity from LC. ADCtotal was helpful for distinguishing adenocarcinoma and non-adenocarcinoma. A combination of DCE-MRI and IVIM could provide a robust method to determine the microstructural characteristics of SPLs. (C) 2019 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.