Diffusion kurtosis imaging in assessment of gastric cancer aggressiveness

Background: Diffusion kurtosis imaging (DKI) has been utilized in various tumors. The potential associations between parameters derived from DKI and the aggressiveness of gastric cancers are still unclear. Methods: Forty-nine patients with gastric cancers were enrolled in this prospective study. All patients underwent magnetic resonance (MR) examination before surgery. All MR images were reviewed by two radiologists using software IDL 6.3 and an oval region of interest (ROI) was manually drawn on the specific slice showing the largest area of tumor. Three parameters were calculated automatically: apparent diffusion coefficient (ADC), corrected diffusion coefficient (diffusivity) and excess diffusion kurtosis coefficient (kurtosis). Results: Poorly/moderate-poorly differentiated gastric cancers showed significantly lower ADC and higher kurtosis compared with moderately/well differentiated tumors (P = 0.039, 0.002, respectively). Kurtosis was also significantly different in different Lauren classifications (P = 0.010). ADC and diffusivity were significantly lower while kurtosis was significantly higher in gastric cancers with T3-T4 stages than in those with T1-T2 stages (P = 0.004, 0.021, 0.009, respectively). Lower ADC and diffusivity were also observed in gastric cancers with N1-N3 stages (P = 0.010, 0.023, respectively). No significant differences were found for ADC, diffusivity and kurtosis among different status of vascular invasion and perineural invasion. Conclusions: DKI derived parameters might be helpful in preoperative assessment of gastric cancer's aggressiveness, especially in identifying poorly/moderate-poorly differentiated or diffuse type gastric cancers, and in predicting the status of lymph nodes metastasis.