体素内不相干运动成像用于直肠腺癌术前评估的价值

Intravoxel incoherent motion in preoperative evaluation of rectal adenocarcinoma

目的探讨体素内不相干运动成像(IVIM)用于直肠腺癌术前评估的价值。方法收集2017年12月至2018年12月中国医科大学附属盛京医院结直肠外科术后病理证实为原发直肠腺癌的54例患者的磁共振成像图像(包括IVIM序列)及相关临床资料。根据肿瘤是否突破固有肌层将肿瘤分为未突破固有肌层组(T1、T2期,15例)和突破固有肌层组(T3、T4期,39例)。根据术后病理结果将肿瘤分为高、中、低分化3组(15、32、7例)。测量直肠腺癌组织的IVIM相关参数,包括标准表观扩散系数(ADC)、单纯扩散系数(D)、灌注相关扩散系数(D^*)和灌注分数(f);比较不同T分期及分化程度肿瘤间各参数的差异。结果未突破固有肌层组的ADC、f值分别为(1.03±0.07)×10^-3mm^2/s、(0.36±0.04),突破固有肌层组的ADC、f值为(0.96±0.11)×10^-3mm^2/s、(0.28±0.03);2组间ADC、f值差异有统计学意义(P=0.034、P<0.001)。2组间的D、D^*值差异无统计学意义(P>0.05)。低、中、高分化组的ADC值分别为(0.799±0.105)×10^-3mm^2/s、(0.978±0.066)×10^-3mm^2/s、(1.063±0.059)×1010^-3mm^2/s,D值分别为(0.797±0.074)×10^-3mm^2/s、(0.890±0.076)×10^-3mm^2/s、(1.050±0.081)×10^-3mm^2/s;ADC、D值随着肿瘤分化程度的增加而逐渐升高,组间两两比较差异均有统计学意义(均P<0.001)。ADC、D值与肿瘤分化程度呈高度正相关(r=0.676、0.722,均P<0.05)。3组间的D^*、f值差异无统计学意义(P>0.05)。结论ADC、f值有助于鉴别突破固有肌层与未突破固有肌层的直肠腺癌;ADC、D值与直肠腺癌分化程度呈高度正相关,有助于术前评估肿瘤的分化程度。

Objective To investigate the value of intravoxel incoherent motion(IVIM)in preoperative evaluation of rectal adenocarcinoma.Methods Nuclear magnetic resonance images(including IVIM sequences)and general clinical data were collected from 54 patients with rectal adenocarcinoma admitted to Shengjing Hospital of China Medical University from December 2017 to December 2018.According to whether the tumor broke through muscularis propria,the patients were divided into non-breaking group(phase T1 and T2,15 cases)and breakthrough group(phase T3 and T4,39 cases).According to postoperative pathological results,the patients were divided into high,medium and low differentiation groups(respectively 15,32,7 cases).IVIM parameters including apparent diffusion coefficient(ADC),diffusion coefficient(D),perfusion-related diffusion coefficient(D^*)and perfusion fraction(f)were measured and analyzed among tumors with different T phases and differentiation degrees.Results ADC and f values were(1.03±0.07)×10^-3mm^2/s,(0.36±0.04)in the non-breaking group and(0.96±0.11)×10^-3mm^2/s,(0.28±0.03)in the broke through group,with statistically significant differences between the two groups(P=0.034,P<0.001).No significant differences were noticed regarding D and D^*values between groups(P>0.05).Higher ADC and D values were observed with higher tumor differentiation degree[ADC(0.799±0.105),(0.978±0.066),(1.063±0.059)×10^-3mm^2/s and D(0.797±0.074),(0.890±0.076),(1.050±0.081)×10^-3mm^2/s for the low,medium and high differentiation groups](all P<0.001).ADC and D values were positively correlated with tumor differentiation degree(r=0.676,0.722,both P<0.05).There were no significant differences in D^*and f values among the three groups(P>0.05).Conclusions ADC and f values can help identify rectal adenocarcinoma that breaks through muscularis propria or not.ADC and D values are positively correlated with the differentiation degree of rectal adenocarcinoma.