Quantitative analyses of the correlation between dynamic contrast-enhanced MRI and intravoxel incoherent motion DWI...

This study investigated the correlation between dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and intravoxel incoherent motion diffusion-weighted imaging (IVIM DWI) to differentiate thyroid nodules. Quantitative DCE-MRI parameters, including the transfer constant (K ^trans), rate constant (K _ep) and volume fraction of the extracellular extravascular space (V _e), were calculated. The diffusion coefficient (D), pseudo-diffusion coefficient (D ), and perfusion fraction (f) were derived from biexponential fitting of IVIM DWI. A total of 38 nodules, including 22 malignant and 16 benign nodules, were analyzed. The K ^trans, K _ep and V _e for benign lesions were 1.32 ± 0.76 min^-1, 6.44 ± 1.44 min^-1, and 2.02 ± 0.89 min^-1, respectively, and for malignant lesions, the values were 0.84 ± 0.30 min^-1, 5.43 ± 1.38 min^-1, and 1.71 ± 0.83 min^-1, respectively (P = 0.027, 0.036, and 0.257, respectively). The D, f, and D for benign lesions were 1.51 ± 0.52 mm²/s, 26.63 ± 8.75%, and 15.84 ± 8.71 mm²/s, respectively, and for malignant lesions, the values were 0.68 ± 0.17 mm²/s, 31.63 ± 10.72%, and 11.10 ± 4.21 mm²/s, respectively (P [< 0.0001, 0.135, 0.058], respectively). No significant correlations were found between IVIM DWI and DCE-MRI quantitative parameters (all P > 0.05). In benign nodules, a moderate inverse correlation was found between D and K _ep (r = -0.54, P = 0.031). IVIM DWI shows no significant correlation with perfusion parameters derived from DCE-MRI; however, IVIM DWI combined with quantitative DCE-MRI may be a useful imaging tool for the assessment of thyroid nodules in clinical studies.