Application of Diffusion Kurtosis Imaging and Histogram Analysis for Assessing Preoperative Stages of Rectal Cancer.

Objective: To explore the value of diffusion kurtosis imaging (DKI) and histogram analysis for assessing preoperative stages and heterogeneity in rectal cancer.

Methods: Fifty patients with pathologically confirmed rectal adenocarcinoma were enrolled. The value of DKI parameters and histogram metrics for assessing the preoperative stages and heterogeneity in rectal cancer was analyzed retrospectively.

Results: (1) ADC-10th percentile and ADC-25th percentile were significantly higher in T1-2 than in the T3-4 rectal cancer (the ADC values were 0.65 ± 0.08 × 10-3  mm2 /s versus 0.58 ± 0.11 × 10-3  mm2 /s and 0.73 ± 0.11 × 10-3  mm2 /s versus 0.65 ± 0.11 × 10-3  mm2 /s; p values were 0.035 and 0.024, resp.). (2) D -10th percentile and D -25th percentile were also significantly higher in T1-2 than in T3-4 rectal cancer (the D values were 0.96 ± 0.19 × 10-3  mm2 /s versus 0.84 ± 0.16 × 10-3  mm2 /s and 1.15 ± 0.27 × 10-3  mm2 /s versus 0.99 ± 0.18 × 10-3  mm2 /s; p values were 0.017 and 0.044, resp.). (3) K value and its histogram metrics showed no statistically significant difference between T1-2 and T3-4. (4) D -10th had the largest area under the curve (AUC 0.799) among all the parameters; the sensitivity and specificity were 84.2 and 61.3%, respectively. (5) DKI combined with traditional MRI had an accuracy of 68% while assessing the lymph node of rectal cancer.

Conclusion: DKI parameters and histogram metrics are rather valuable in assessing the preoperative stages of rectal cancer; D -10th percentile exhibits the highest diagnostic efficiency.