ObjectiveTo explore the application value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) quantitative parameters and apparent diffusion coefficient (ADC) value in evaluating the differentiation degrees and T stages of rectal cancer.MethodsThe patients with rectal cancer from November 2017 to November 2019 in the Sichuan Provincial People’s Hospital were collected. The volume transfer constant (Ktrans), flux rate constant (Kep), and extravascular extracellular volume fraction (Ve), and ADC values of the tumors were measured and compared in the patients with the different differentiation degrees and T stages. The receiver operating characteristic (ROC) curve analysis was performed.ResultsAll of 53 eligible patients were included, including 13 cases of high differentiation, 30 cases of medium differentiation, and 10 cases of low differentiation; 5 cases of T1 stage, 8 cases of T2 stage, 24 cases of T3 stage, and 16 cases of T4 stage. ① There were statistical differences in the Ktrans and ADC values among the different differentiation degrees of rectal cancer (P=0.004, P<0.001), and no statistical differences in the Kep and Ve values (P>0.050) among them. The Ktrans value was increased with decreased differentiation degree (P<0.050), the ADC value was decreased with decreased differentiation degrees (P<0.050). ② There were statistical differences in the Ktrans and ADC values among the different T stages of rectal cancer (P=0.002; P=0.007), and no statistical differences in the Kep and Ve values (P>0.050) among them. The Ktrans and ADC values were statistically different between the T2 and T3 stages of rectal cancer (P=0.009, P=0.013). ③ The Ktrans and ADC values could distinguish the high and medium differentiation degrees of rectal cancer, its area under ROC curve (AUC) values were 0.677 and 0.763, respectively, and the corresponding best thresholds were 0.180/min and 1.179 mm2/s; The Ktrans and ADC values could distinguish the medium and low differentiation degrees of rectal cancer, its AUC values were 0.693 and 0.967, and the corresponding best thresholds were 0.281/min and 0.906 mm2/s; The Ktrans and ADC values could distinguish the T2 and T3 stages of rectal cancer, its AUC values were 0.862 and 0.742, and the corresponding best thresholds were 0.204/min and 1.579 mm2/s.ConclusionDCE-MRI quantitative parameters and ADC value before surgery to determine the different differentiation degrees and T stages of rectal cancer have certain reference value, the best Ktrans and ADC thresholds to distinguish different differentiation degrees and T2 to T3 stages can be obtained through statistical analysis.