Value of IVIM-DWI and DCE-MRI in the assessment of benign and malignant mesorectal lymph nodes in rectal cancer / 实用放射学杂志

ABSTRACT

Objective To investigate the diagnostic value of intravoxel incoherent motion diffusion weighted imaging (IVIM-DWI) and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI)in differentiating non-metastatic from metastatic mesorectal lymph nodes in rectal cancer.Methods IVIM-DWI and DCE-MRI were performed preoperatively in 38 patients with histologically proven rectal carcinoma.The short axis diameter,short-to-long axis diameter ratio,four IVIM-based parameters (ADC,D,D? and f) and six DEC-MRI semi-quantitative parameters (Slope,Maxslope,CER,Washout,TTP,iAUC90 and iAUC180 )were compared between the metastatic (n=28)and non-metastatic (n=27)lymph nodes.Results There were significant statistical significances between the metastatic and non-metastatic lymph nodes in mean short axis diameter (8.87 mm±2.829 mm vs 6.83 mm±1.075 mm),D value[(0.824±0.1 13)× 10 -3 mm2/s vs (1.033±0.244)× 10 -3 mm2/s],CER(1.588 ±0.664 vs 1.054 ±0.41 9),iAUC90 (22.89 ± 9.83 vs 13.59 ± 5.34)and iAUC1 80 (49.38±20.1 9 vs 30.31 ± 1 1.67)(P ≤0.001).The short-to-long axis diameter ratio,ADC,D? ,f,Slope,Maxslope,Washout and TTP values did not show significant differences between the two groups(P >0.05).The respectively optimal cut-off value (area under the curve,sensitivity and specificity)for distinguishing metastatic from non-metastatic lymph nodes were as followsshort axis diameter=7.1 mm(0.744,64.2%,85.1%),D=0.906×10 -3 mm2/s (0.821,81.5%,75.0%),CER=1.05(0.749,85.7%,62.9%), iAUC90 =13.42(0.780,85.7%,62.9%),iAUC180 =49.65 (0.770, 50.0%,100%)respecyively.Conclusion Both IVIM-DWI and DCE-MRI are useful for differentiating non-metastatic from metastatic mesorectal lymph nodes in rectal cancer.