RESUMO
Objective To compare the value of transrectal ultrasonography(TRUS) and magnetic resonance(MR) in preoperative estimation of circumferential resection margin (CRM) of mid-low rectal cancer.Methods Both TRUS and MR were performed prior to surgery in 111 patients with mid-low rectal cancer.The CRM was evaluated and compared with the postoperative pathologic findings.Results The accuracy of TRUS and MR for CRM was 91.9％(102/111) and 85.6％(95/111),respectively,there was no statistical difference between them (P =0.137).Their specificities were 94.0％ (79/84)and 84.5％ (71/84),there was statistical difference between them(P =0.046).The consistency of the results between TRUS and pathology was better than that between MR and pathology(Kappa1 =0.783,Kappas =0.652).Conclusions TRUS is proved to have an important diagnostic value for CRM of mid-low rectal cancer.