Résumé
Objective To evaluate the value of 3T magnetic resonance imaging (MRI) in the preoperative T staging of potentially resectable esophageal cancer(EC), compared with endoscopic ultrasonography (EUS). Methods Patients with resectable EC pathologically confirmed by biopsy from March 2015 to September 2016 were prospectively enrolled. All patients underwent MRI (including T2-TSE-BLADE,DWI and radial-VIBE)and EUS one week after the biopsy,and MRI were performed prior to EUS, both MRI and EUS were acquired within one week before surgery. Two readers with more than 5 years experiences in the MRI diagnosis evaluated the MR image quality using a 5-point score independently. T staging was assigned on MRI and EUS by the two MRI readers using double-blind method and one endoscopist in accordance with the 7th edition of AJCC TNM Classification for EC, and any disagreement between two MRI readers was resolved by consensus with discussion to the third senior MRI doctor. The inter-observer agreement between two MRI readers were calculated using Kappa test for image quality scores and T staging results. Considering postoperative pathological T staging results as the gold standard, the performances of MRI and EUS were evaluated based on the accuracy rate and analyzed by χ2 test. Results A total of 70 patients were enrolled in the study, the good image quality cases (≥ 3 scores) were 66 in reader 1 and 68 in reader 2. The inter-observer agreement of the image quality scores by two readers was excellent (Kappa=0.824, P<0.05). The pathological results revealed 16 cases of T1 stage, 18 cases of T2 stage, 30 cases of T3 stage, and 6 cases of T4a stage. The inter-observer agreement of the preoperative T staging of EC by two readers was excellent (Kappa=0.809, P<0.05). The accuracy rates of MRI and EUS for preoperative T staging of EC were 92.9% (65/70) and 67.1% (47/70), respectively, and the difference in accuracy rates of two techniques was statistically significant (χ2=14.5, P<0.05). Conclusions The accuracy rate of MRI for preoperative T staging of EC is significantly higher than that of EUS. MRI can be used as a noninvasive method for preoperative T staging of EC.