Objective:To explore the added value of reduced field of view(rFOV)image recon-struction using image-space sampling function(IRIS)DWI(rFOV IRIS-DWI)sequence combined with T2WI sequence in evaluating T staging of rectal cancer.Methods:All patients who underwent rec-tal MRI examination in our institution between June 2022 and August 2022 were retrospectively ana-lyzed.All patients were performed MR scan at a 3.0T MR scanner(Ingenia Elition,Philips,Nether-lands).The rFOV IRIS-DWI sequence and high-resolution oblique axial T2WI sequence were scanned for analysis.All images were evaluated by a senior radiologist specialized with more than 20 years of experience in rectal cancer research by two rounds.First,the mrT staging were evaluated based on high-resolution oblique axial T2WI images.Second,conducted one week later,the mrT staging were re-evaluated based on rFOV IRIS-DWI combined with high-resolution oblique axial T2WI images.The twice mrT staging results were recorded respectively.MedCalc statistical software(version 18.2.1)was used for data analysis.The accuracy of two diagnosis methods for pT staging were compared by Fisher's precision probability test.Receiver operating characteristic(ROC)curve was used to evaluate the diagnostic performance of two methods for pT staging.Paired sample t test was used to diagnose the confidence difference value(D-value)between the two methods if D-value was normal distribution and paired Wilcoxon S rank sum test was used if the D-value was non-normal distribution.P＜0.05 in-dicated the difference was statistically significant.Results:Twenty-seven rectal cancer patients were en-rolled in this retrospectively study.The median age of all patients was 69 years(ranged from 53 to 81 years).According to the rFOV IRIS-DWI combined with high-resolution oblique axial T2WI sequence,11 patients(91.7％)were accurately diagnosed in all 12 pT1-T2 staging patients,and 14 patients(93.3％)were accurately diagnosed in all 15 pT3 staging patients.One(6.7％)pT3 patient was under-staged as mrT1-2 staging,and one(8.3％)pT1-2 staging patient was over-staged as mrT3 staging,respectively.The difference was statistically significant(P＜0.0001).The sensitivity,specifity and area under the curve(AUC)based on rFOV IRIS-DWI combined with T2WI sequence and T2WI sequence were 0.928,93.3％,91.7％ and 0.658,73.3％,58.3％,respectively.The difference of AUC between two methods was statistically significant(P=0.002).For all patients enrolled,the diagnosis confidence based on rFOV IRIS-DWI combining T2WI sequence was higher than single T2WI sequence(2.9 vs.2.37,with P=0.0002).Conclusion:rFOV IRIS-DWI combining T2WI sequence may significantly im-prove the diagnosis efficiency and confidence for rectal cancer T staging.
关键词
直肠癌/T分期/小视野/扩散加权成像/诊断效能
Key words
Rectal cancer/T staging/Reduced field of view/Diffusion weighted imaging/Di-agnosis efficiency
维普
万方数据