背景:这项研究的目的是前瞻性地研究使用整合的切片特异性动态匀场(iShim)技术对原发性食管鳞状细胞癌(ESCC)分期和预测ESCC淋巴结转移的诊断表现。
方法:2016年4月至2019年4月前瞻性纳入63例ESCC患者。术前在3.0TMRI系统上使用iSim技术(b=0、25、50、75、100、200、400、600、800s/mm2)进行MR和IVIM。原发性肿瘤表观扩散系数(ADC)和IVIM参数,包括真实扩散系数(D),伪扩散系数(D*),假扩散分数(f)由两个独立的放射科医生测量。D的差异,D*,评估不同T和N阶段的f和ADC值。计算了组内相关系数(ICC),以评估两个读者之间的观察者之间的一致性。D的诊断性能,D*,使用受试者工作特征(ROC)曲线分析确定ESCC原发肿瘤分期和淋巴结转移预测中的f和ADC值。
结果:对于IVIM参数和ADC,观察者间的共识非常好(D:ICC=0.922;D*:ICC=0.892;f:ICC=0.948;ADC:ICC=0.958)。ADC,D,T1+T2组的D*和f值明显高于T3+T4a组[ADC:(2.55±0.43)×10-3mm2/svs.(2.27±0.40)×10-3mm2/s,t=2.670,P=0.010;D:(1.82±0.39)×10-3mm2/svs.(1.53±0.33)×10-3mm2/s,t=3.189,P=0.002;D*:46.45(30.30,55.53)×10-3mm2/svs.32.30(18.60,40.95)×10-3mm2/s,z=-2.408,P=0.016;f:0.45±0.12vs.0.37±0.12,t=2.538,P=0.014]。ADC,淋巴结阳性(N+)组的D值和f值明显低于淋巴结阴性(N0)组[ADC:(2.10±0.33)×10-3mm2/svs.(2.55±0.40)×10-3mm2/s,t=-4.564,P<0.001;D:(1.44±0.30)×10-3mm2/svs.(1.78±0.37)×10-3mm2/s,t=-3.726,P<0.001;f:0.32±0.10vs.0.45±0.11,t=-4.524,P<0.001]。D的组合,在区分组T1+T2和组T3+T4a时,D*和f产生最高的曲线下面积(AUC)(0.814)。D结合f在鉴定ESCC的N+组和N0组时提供了最高的诊断性能(AUC=0.849)。
结论:IVIM可以作为一种有效的功能成像技术来评估原发肿瘤的术前分期和预测ESCC淋巴结转移的存在。
BACKGROUND: The aim of this research is to prospectively investigate the diagnostic performance of intravoxel incoherent motion (IVIM) using the integrated slice-specific dynamic shimming (iShim) technique in staging primary esophageal squamous cell carcinoma (ESCC) and predicting presence of lymph node metastases from ESCC.
METHODS: Sixty-three patients with ESCC were prospectively enrolled from April 2016 to April 2019. MR and IVIM using iShim technique (b = 0, 25, 50, 75, 100, 200, 400, 600, 800 s/mm2) were performed on 3.0T MRI system before operation. Primary tumour apparent diffusion coefficient (ADC) and IVIM parameters, including true diffusion coefficient (D), pseudodiffusion coefficient (D*), pseudodiffusion fraction (f) were measured by two independent radiologists. The differences in D, D*, f and ADC values of different T and N stages were assessed. Intraclass correlation coefficients (ICCs) were calculated to evaluate the interobserver agreement between two readers. The diagnostic performances of D, D*, f and ADC values in primary tumour staging and prediction of lymph node metastasis of ESCC were determined using receiver operating characteristic (ROC) curve analysis.
RESULTS: The inter-observer consensus was excellent for IVIM parameters and ADC (D: ICC = 0.922; D*: ICC = 0.892; f: ICC = 0.948; ADC: ICC = 0.958). The ADC, D, D* and f values of group T1 + T2 were significantly higher than those of group T3 + T4a [ADC: (2.55 ± 0.43) ×10- 3 mm2/s vs. (2.27 ± 0.40) ×10- 3 mm2/s, t = 2.670, P = 0.010; D: (1.82 ± 0.39) ×10- 3 mm2/s vs. (1.53 ± 0.33) ×10- 3 mm2/s, t = 3.189, P = 0.002; D*: 46.45 (30.30,55.53) ×10- 3 mm2/s vs. 32.30 (18.60,40.95) ×10- 3 mm2/s, z=-2.408, P = 0.016; f: 0.45 ± 0.12 vs. 0.37 ± 0.12, t = 2.538, P = 0.014]. The ADC, D and f values of the lymph nodes-positive (N+) group were significantly lower than those of lymph nodes-negative (N0) group [ADC: (2.10 ± 0.33) ×10- 3 mm2/s vs. (2.55 ± 0.40) ×10- 3 mm2/s, t=-4.564, P < 0.001; D: (1.44 ± 0.30) ×10- 3 mm2/s vs. (1.78 ± 0.37) ×10- 3 mm2/s, t=-3.726, P < 0.001; f: 0.32 ± 0.10 vs. 0.45 ± 0.11, t=-4.524, P < 0.001]. The combination of D, D* and f yielded the highest area under the curve (AUC) (0.814) in distinguishing group T1 + T2 from group T3 + T4a. D combined with f provided the highest diagnostic performance (AUC = 0.849) in identifying group N + and group N0 of ESCC.
CONCLUSIONS: IVIM may be used as an effective functional imaging technique to evaluate preoperative stage of primary tumour and predict presence of lymph node metastases from ESCC.