表观扩散系数和MRI体素内不相干运动参数值在肝外胆管癌病理分级中的价值

Application value of MRI apparent diffusion coefficient and intravoxel incoherent motion in grading of extrahepatic cholangiocarcinoma

目的探讨DWI的ADC值及体素内不相干运动（IVIM）相关参数值在肝外胆管癌（EHCC）病理分级中的价值。方法回顾性分析经手术病理证实为EHCC，术前行上腹部常规MRI平扫和DWI检查，且病灶最小直径〉5mm的38例患者资料。将扫描原始图像导入IVIM图像后处理软件，每例患者各放置3次ROI，3次时间间隔均为1周，在病灶最大层面实性部分同一位置选取尽可能大面积的ROI,测量病灶ADC、血流量（BF）、体素内真性水分子扩散（D）、体素内微循环灌注（D^＊）、灌注分数（f）值，取3次的平均值。对手术标本按照消化系统肿瘤WHO分类分级法，分为Ⅰ、Ⅱ、Ⅲ级。采用Spearman相关分析评价ADC值及IVIM参数与EHCC病理分级的相关性，采用ROC曲线分析ADC、BF、D、D^＊、f值诊断EHCC病理分级的效能。结果38例EHCC中，Ⅰ、Ⅱ、Ⅲ级分别为11、15、12例。Ⅰ、Ⅱ、Ⅲ级EHCC的ADC值分别为（1．33±0．22）×10^-3、（1．21±0．18）×10^-3、（0．98±0．10）×10^-3mm／s^2，BF值分别为（2．40±1．01）×10^-3、（2．37±1．19）×10^-3、（1．64±0．46）×10^-3mm／s^2，D值分别为（1．30±0．13）×10^-3、（1．15±0．13）×10^-3、（0．87±0．11）×10^-3mm/s^2，D^2值分别为（5．67±0．70）×10^-3、（6．58±1．82）×10^-3、（5．43±2．82）×10^-3mm／s^2，f值分别为（38．03±10．02）％、（31．36±8．34）％、（22．04±7．93）％。ADC、D、f值和病理分级具有相关性（r值分别为0．624、0．809和0．580，P值均〈0．01）；BF、D^＊值和病理分级间无相关性（r值分别为0．27l、0．017，P值分别为0．099、0．920）。ADC、BF、D、D^＊、f值诊断EHCC病理分级的ROC曲线下面积分别为0．785、0．603、0．889、0．421、0．781。结论随着EHCC分化程度的降低，ADC、D、f值均降低。f值与病理分化程度相关性较低，ADC、D值相关性好，D值的相关性最高。

Objective To evaluate the value of DWI parameter ADC and intravoxel incoherent motion（IVIM） derived parameters in grading extrahepatic cholangioearcinoma（EHCC）. Methods Thirty-eight consecutive patients with surgically resected and pathologically confirmed EHCC while the minimum diameter of the lesions large than 5 mm were included in this retrospective study. Patients underwent upper abdomen 3.0 T MR（including conventional MRI and DWI seansequences）. Importing original images into the IVIM post-processing software, each patient were set three times of ROIs and each time interval was one week. ROI were selected in the same position of the maximum solid part of lesions area, the average value of ADC, blood flow（BF）, pure molecular diffusion（D）, perfusion-based molecular diffusion（D^＊）, perfusion fraction（f） were measured. According to WHO digestive tumor specimens grading method, divided these cases into [ , lI, m grade group. Evaluate the association by Spearman correlation analysis and compare the diagnostic potential of parameters ADC, BF, D, D^＊, f by using ROC analysis. Results Thirty eight eases of EHCC include： grade Ⅰ 11 cases, grade Ⅱ 15 cases and grade Ⅲ 12 cases. ADC values of these three groups were （ 1.33 ±0.22）×10^-3, （ 1.21± 0.18） ×10^-3, （0.98 ±0.10）×10^-3mm^2/s, respectively. B F values were （2.40 ± 1.01 ） ×10^-3, （2.37± 1.19 ）×10^-3, （ 1.64 ± 0.46 ） ×10^-3mm^2/s. D values were （1.30±0.13） ×10^-3, （1.15±0.13）×10^-3, （0.87±0.11 ） ×10^-3mm^2/s. D^＊ values were （5.67±0.70）×10^-3, （6.58± 1.82 ） ×10^-3, （ 5.43 ± 2.82 ）×10^-3mm^2/s. And f values were （ 38.03 ± 10.02 ） %, （ 31.36 ± 8.34 ） %, （ 22.04 ± 7.93 ） %. ADC, D, and f values were significantly correlated with histologie grade（r=0.624,0.809,0.580; P〈0.01, respectively）. BF and D^＊ were both not signifieantly correlated（r=0.271,0.017; P=0.099,0.920, respectively）. Areas under the ROC curve for the five parameters ADC,BF, D,D^＊,f were 0.785,0,603,0.889,0.421,0.781, respectively. Conclusions With the reduction of histological differentiation degree, ADC,D,f values decreased. Correlation between f value and pathological differentiation degree is poor whie the correlation of D and ADC were excellent, and the correlation of D is the highest.