Diffusion kurtosis imaging and dynamic contrast-enhanced MRI for the differentiation of parotid gland tumors.

OBJECTIVE

To assess the usefulness of combined diffusion kurtosis imaging (DKI) and dynamic contrast-enhanced MRI (DCE-MRI) in the differentiation of parotid gland tumors.

METHODS

Seventy patients with 80 parotid gland tumors who underwent DKI and DCE-MRI were retrospectively enrolled and divided into four groups: pleomorphic adenomas (PAs), Warthin tumors (WTs), other benign tumors (OBTs), and malignant tumors (MTs). DCE-MRI and DKI quantitative parameters were measured. The Kruskal-Wallis H test and post hoc test with Bonferroni correction and ROC curve were used for statistical analysis.

RESULTS

WTs demonstrated the highest K value (median 1.89, interquartile range [1.46-2.31] min) but lowest V value (0.20, [0.15-0.25]) compared with PAs (K, 0.34 [0.21-0.55] min; V, 0.36 [0.24-0.43]), OBTs (K, 1.22 [0.27-1.67] min; V, 0.28 [0.25-0.41]), and MTs (K, 0.71 [0.50-1.23] min; V, 0.35 [0.26-0.45]) (all p < .05). MTs had the lower D value (1.10, [0.88-1.29] × 10 mm/s) compared with PAs (1.81, [1.60-2.20] × 10 mm/s) and OBTs (1.57, [1.32-1.89] × 10 mm/s) (both p < .05). PAs had the lower K value (0.12, [0.07-0.18] min) compared with OBTs (0.28, [0.11-0.50] min) (p < .05). The cutoff values of combined K and V, D, and K to distinguish WTs, MTs, and PAs sequentially were 1.06 min, 0.28, 1.46 × 10 mm/s, and 0.21 min, respectively (accuracy, 89% [71/80], 91% [73/80], 78% [62/80], respectively).

CONCLUSION

The combined use of DKI and DCE-MRI may help differentiate parotid gland tumors.

KEY POINTS

• The combined use of DKI and DCE-MRI could facilitate the understanding of the pathophysiological characteristics of parotid gland tumors. • A stepwise diagnostic diagram based on the combined use of DCE-MRI parameters and the diffusion coefficient is helpful for accurate preoperative diagnosis in parotid gland tumors and may further facilitate the clinical management of patients.