Comparison Of Magnetic Resonance Imaging And Endorectal Ultrasound In Preoperative Local Staging Of Rectal Cancer

Objective: To compare the value of magnetic resonance imaging(MRI)and endorectal ultrasound (ERUS) in preoperative local staging of rectalcancer.Method: To analyze31cases of patients with primary rectal cancer whowere treated in the Fourth Affiliated Hospital of Hebei Medical University, theSecond General Surgery from August2013to March2014and performedpreoperative staging by MRI and ERUS examination,including17males and14females,with the mean age of57.6±10.6years old。All the results werecompared with postoperative staging to determine the accuracy, sensitivity andspecificity of MRI and ERUS for rectal cancer depth of invasion (T stage) andregional lymph node metastasis (N stage).Results：1Forty cases of rectal cancer which performed T and N stage by MRIand ERUS were compared with postoperative pathological staging,in whichfour cases can not be obtained due to referral staging, five cases of invasivelesions were stricture disease or high lesions, ultrasound probe can not pass orreach, therefore a total9case was removed due to inability to perform T, Nstaging.There are31cases of rectal cancer ultimately enrolled in the study.2Overall accuracy of MRI and ERUS preoperative T staging of rectalcancer were66.7%(21/31) and64.5%(20/31), the difference was notstatistically significant (P>0.05). Diagnostic accuracy of Tis, T1, T2, T3, T4period by MRI and ERUS were96.8%(30/31) and96.8%(30/31),90.3%(28/31) and96.9%(28/31),74.2%(23/31) and77.4%(24/31),77.4%(24/31)and67.7%(21/31),96.8%(30/31) and90.3%(28/31), the difference were notstatistically significant (P>0.05); the sensitivity were0(0/1) and0(0/1)0(0/1) and100%(1/1),0(0/4) and50.0%(2/4),85.7%(18/21) and76.2% (16/21),75.0%(3/4) and25.0%(1/4); the specificity was100%(30/30) and100%(30/30),93.3%(28/31) and96.7%(30/31),85.2%(23/27) and81.5%(22/27),60.0%(6/10) and50.0%(5/10),100%(27/27) and100%(27/27).3Diagnostic accuracy of N staging of rectal cancer by MRI and ERUSwere58.1%(18/31) and51.6%(16/31), the sensitivity was77.8%(14/18)and47.1%(8/17), the specificity was30.8%(4/13) and57.1%(8/14),the difference was not statistically significant (P>0.05).Conclusion:1There was no statistical difference in assessing the overall accuracy ofpreoperative T staging of rectal cancer by MRI and ERUS. MRI and ERUSwas fair in assessment of Tis staging of rectal cancer; Compared withERUS,MRI has much poor accuracy and sensitivity in assessment ofpreoperative locally early(T1and T2staging) rectal cancer,may be associatedwith good judgment on adjacent tissues of ERUS; When it came to the locallyadvanced (T3ang T4staging)rectal cancer, MRI had much higher accuracy,sensitivity than ERUS in T staging, may be associated with broad perspectiveof MRI.2There was no difference statistically in assessing the overall accuracyof preoperative N staging of rectal cancer by MRI and ERUS. The accuracyand sensitivity of MRI was superior to ERUS, but the specificity was inferiorto ERUS In the evaluation of N staging, may be associated with high spatialand temporal resolution, relatively low SNR of MRI.