APPLICATION OF MRI IN PREOPERATIVE DIAGNOSIS AND STAGING IN RECTAL CANCER

Objective To assess the value of magnetic resonance imaging(MRI) in preoperative diagnosis and clinical staging of rectal cancer. Methods A TN staging was undertaken by MRI in 48 patients with rectal cancer,the result was compared with pathology. Results The final diagnosis for rectal cancer by MRI was 100%.For T staging,39 cases were correct,and nine were wrong: in which,six cases with T1-T2 were reported as T3;three with T3 reported as T1-T2.The totally accurate rate of T staging was 81.3%(39/48),in which,the accuracy in T1-T2 staging was 86.3%(19/22),in T3 was 66.7%(12/18) and T4 was 100%(8/8).A statistic analysis indicated that preoperative MRI staging was better consistent with pathologic staging(Kappa=0.696,P0.01).For MRI lymph node staging,the accurate was 36 cases,error in 12;in which,overstaged and understaged was six,respectively.The accuracy of node staging was 75.0%(36/48),sensitivity was 68.4%(13/19),and specificity was 79.3%(23/29).MRI could make a relatively correct prediction for lymph node staging in cancer of the rectum(Kappa=0.573,P0.05). Conclusion Preoperative MRI staging can relatively make an exact evaluation of the depth of tumor infiltration and lymph node metastasis and TN staging in rectal cancer.