常规MRI与弥散加权成像测量的肿瘤容积对直肠癌TN分期的诊断价值

目的探讨常规MRI与弥散加权成像(DWI)测量的肿瘤容积对直肠癌TN分期的诊断价值。材料与方法对经肠镜确诊的74例直肠癌患者行盆腔3.0 T MRI检査。分析MRI对直肠癌术前TN分期的准确性,用检验评价MRI术前TN分期与病理分期的一致性。用单因素方差分析评价DWI(b=10000 s/mm~2)测量的肿瘤容积与病理TN分期的相关性。结果MRI诊断直肠癌T、N分期的准确率分别为87.8%(66/74)、66.2%(49/74);病理学和MRI对T分期诊断有较好的一致性(Kappa=0.78,P=0.000)、对N分期诊断一致性较差(Kappa=0.33,F=0.000)。在DWI上测量肿瘤容积≤T2期、T3期、T4期分别为(4145.13±718,00)mm~3、(14939.73±3591.38)mm~3、(22714.76±4251.71)mm~3;N0期、N1期、N2期分别为(14367.15±6425.83)mm~3,(17967.69±5259.88)mm~3、(19464.00±3588.77)DWI测肿瘤容积越大直肠癌T分期越高,差异有统计学意义(F=75.189,P=0.000);肿瘤容积与直肠癌不同N分期间差异有统计学意义(F=3.545,P=0.034)。结论MRI评价直肠癌T分期准确率较高,对N分期也有一定诊断价值。MR肿瘤容积测量对直肠癌TN分期有重要参考价值。

Value of magnetic resonance imaging combined with diffusion-weighted MR tumor volumetry in the diagnosis of TN staging for rectal cancer

Objective:To investigate the value of magnetic resonance imaging (MRI) in the diagnosis of preoperative TN staging for rectal cancer and the correlation between diffusion-weighted MR tumor volumetry and TN staging.Materials and Methods:Between September 2014 and February 2016, 74 patients with histologically proven rectal cancer by the colonoscopic biopsy in our hospital was performed by pelvic 3.0 T MRI. We analyzed the preoperative MRI TN staging of rectal cancer diagnosis accuracy. Concordance between MRI TN staging of tumor and pathologic reporting was assessed by means of theKappa statistic. The correlation between diffusion-weighted MR tumor volumetry and TN staging was analyzed byone-way analysis of variance.Results:The accurate rate for T-staging of rectal cancer using MRI was 87.8% (66/74). There was a good correlation between pathologic and MRI tumor staging (Kappa=0.78,P=0.000). The accurate rate for N-staging of rectal cancer using MRI was 66.2% (49/74). There was a poor correlation between pathologic and MRI tumor staging (Kappa=0.33,P=0.000). The tumor volume of rectal cancer at DWI in≤T2, T3and T4 staging rectal cancer was (4145.13±718.00) mm3, (14939.73±3591.38) mm3 and (22714.76±4251.71) mm3. The tumor volume of rectal cancer at DWI in N0, N1 and N2 staging was (14367.15±6425.83) mm3,(17967.69±5259.88) mm3 and (19464.00±3588.77) mm3. The greater of the tumor volume, the higher of the T-staging of rectal cancer, and the discrepancies were statistically different (F=75.189,P=0.000). The discrepancies between tumor volume and N-stagings of rectal cancer were statistically different (F=3.545,P=0.034).Conclusions:MRI has a good concordance with pathologic T-staging of rectal cancer, and has a certain clinical value in the N-staging. DWI tumor volumetry contributes a lot to diagnosis of TN-staging of rectal cancer.