Analysis of the predictive value of IVIM-DWI combined with MRI-DKI for postoperative recurrence in rectal cancer patients undergoing total mesorectal excision
JIANG Dan
QU Xianli
LIU Xiaoliang
YUAN Mei
Abstract：Objective To analyze the predictive value of intravoxel incoherent motion diffusion-weighted imaging(IVIM-DWI)combined with diffusion kurtosis imaging(DKI)in magnetic resonance imaging(MRI)for postoperative recurrence in rectal cancer patients after total mesorectal excision.Methods A total of 120 rectal cancer patients who underwent total mesorectal excision at Nanjing Tianyinshan Hospital from February 2021 to February 2023 were included.All patients underwent IVIM-DWI and MRI-DKI examinations 7 days after surgery and were followed up for 12 months.Based on postoperative recurrence status,they were divided into a recurrence group(62 cases)and a non-recurrence group(58 cases).The IVIM-DWI parameters[apparent diffusion coefficient(ADC),perfusion fraction(f),pseudo-diffusion coefficient(D*),true diffusion coefficient(D)]and MRI-DKI parameters[mean kurtosis(MK),mean diffusivity(MD)]were compared between the two groups.Logistic multivariate regression was used to analyze risk factors for recurrence after total mesorectal excision.A nomogram prediction model was constructed using R software and internally validated by the Bootstrap method.The Hosmer-Lemeshow test was applied to evaluate the goodness of fit.Receiver operating characteristic(ROC)curves were plotted to assess the predictive performance of individual parameters and their combination for recurrence.Results Compared with the non-recurrence group,the recurrence group showed significantly lower ADC,D*,D,and MD values(P＜0.05),and significantly higher f values(P＜0.05).There was no statistically significant difference in MK values between the two groups(P＞0.05).Logistic multivariate regression analysis indicated that lymph node metastasis,differentiation,ADC,D*,D,f,postoperative chemoradiotherapy,and MD were independent risk factors for recurrence after total mesorectal excision(P＜0.05).The Hosmer-Lemeshow goodness-of-fit test indicated good agreement between the predicted values of the nomogram model and the actual observations(x2=7.826,P=0.449),with a concordance index(C-index)of 0.914 and an area under the curve(AUC)of 0.914(95％CI:0.844-0.947),indicating excellent discriminative ability.The combined prediction using IVIM-DWI and MRI-DKI parameters yielded an AUC of 0.847(95％CI:0.784-0.910),which was significantly higher than that of any single parameter(all P＜0.05).Conclusion Recurrence after total mesorectal excision in rectal cancer patients is closely associated with decreased ADC,D*,D,and MD values and increased f values.Combined detection of these imaging parameters can improve the sensitivity of postoperative recurrence prediction and holds important clinical reference value.
Keywords：rectal cancerincoherent motion within voxelsdiffusion-weighted imagingdiffuse kurtosis imagingtotal mesorectal excisionrecrudescence
Publication Date：2026-02-28
Online Publishing Date：2026-04-01(First online date of this platform, not the publication date of the document)
Pages：6( 187-192 )