A comparative study of endoscopic ultrasonography and MRI in preoperative T staging of early rectal cancer

OBJECTIVE : To explore the diagnostic value of ultrasound endoscopy compared with MRI for preoperative T staging of early rectal cancer and to provide a theoretical basis for clinical choices. METHODS : The cases in this study were selected from January 2017 to December 2022, and both EUS and MRI were implemented and preoperative staging was performed before surgery to further clarify the clinical data of 51 patients with early rectal cancer. The sensitivity, specificity and accuracy of EUS and MRI were statistically analyzed to assess their diagnostic efficiency. The concordance between their pathological findings was assessed using Cohen's kappa evaluation method. RESULTS : The overall accuracy of EUS for early T staging was 84.3%, of which the accuracy of Tis and T1 stages was 37.5% and 93.0%, respectively, and the number of cases that did not match the diagnostic criteria was 8, all of which were overstaged. The accuracy of Tis stage with EUS was statistically significantly correlated with postoperative pathology ( c ² =11.029, p =0.001), and the diagnostic agreement with postoperative pathology was good (Kappa=0.580, p =0.000). T1 stage accuracy was statistically significantly correlated with postoperative pathology ( c ² =11.805, p =0.001), and the diagnostic agreement with postoperative pathology diagnosis was good (Kappa=0.555, p =0.000). The overall accuracy of MRI for early T stage was 35.3%, of which the accuracy rate of Tis and T1 stage was 12.5% and 39.5%, respectively, and the number of cases that did not match the diagnostic criteria was 33, all of which were overstaged; the accuracy of MRI for Tis and T1 stage was not statistically significantly correlated with postoperative pathological staging; the diagnostic agreement between T1 stage and postoperative pathological diagnosis was poor (Kappa= 0.009, p >0.05). CONCLUSION : The above results demonstrated the high diagnostic value of ultrasound endoscopy for preoperative staging of early rectal cancer.