Abstract:

Objective　To explore the application value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) combined with diffusion weighted imaging (DWI) in evaluating the postoperative efficacy of interventional therapy for liver cancer. Methods　The case data of 120 patients with liver cancer who underwent interventional therapy at Hubei No.3 People's Hospital, Jianghan University between February 2019 and March 2020 were collected for case control study. According to the therapeutic efficacies, the patients were divided into an effective group (71 cases) and an ineffective group (49 cases). There were 52 males and 19 females in the effective group, and they were (53.16±8.47) years old. There were 31 males and 18 females in the ineffective group, and they were (53.21±8.69) years old. The liver cancer conventional magnetic resonance imaging (MRI), DCE-MRI, and DWI were performed before interventional therapy for liver cancer and 3 weeks after the treatment in the two groups. The apparent diffusion coefficient (ADC) value, transfer constant (K^trans), volume fraction of extracellular extravascular space (Ve), rate constant (Kep), and tumor volume were measured. The differences in ADC, K^trans, Ve, K_ep, and tumor volume were compared between before and after the treatment and between the two groups by independent-sample t test and paired t test. Pearson correlation analysis was adopted to analyze the correlation of liver cancer volume difference with ADC, K^trans, Ve, and Kep differences. Receiver operator characteristic curve (ROC) was drawn to evaluate the value of ADC, K^trans, Ve, and Kep in evaluating the efficacy of interventional therapy for liver cancer. Results　Compared with those before the interventional therapy, the ADC value of patients with liver cancer after intervention was increased to (1.23±0.14) × 10^-3 mm²/s (t=10.970, P<0.05), the K^trans was decreased to (0.18±0.07) min^-1 (t= 9.090, P<0.05), the Kep was reduced to (0.31±0.06) min^-1 (t=11.829, P<0.05), the Ve value was declined to (0.40±0.05) (t=6.252, P<0.05), and the tumor volume was reduced to (10.67±2.48) cm³ (t=26.683, P<0.05). The differences of ADC, K^trans, Kep, and Ve and the tumor volume difference were (0.35±0.08) × 10^-3 mm²/s, (0.24±0.06) min^-1, (0.47±0.12) min^-1, (0.46±0.13), and (10.57±2.34) cm³ in the effective group, which were higher than those in the ineffective group (t=17.525, 12.355, 16.285, 13.835, and 22.747, all P<0.05). The differences of ADC, K^trans, Kep, and Ve were positively correlated with the tumor volume difference (r=0.474, 0.495, 0.375, and 0.365; all P<0.001); and the correlations between the differences of ADC and K^trans and the tumor volume difference were the highest. When the ADC difference was greater than 0.380 × 10^-3mm²/s, the area under the ROC (AUC) was 0.953, the 95% confidence interval (CI) was 0.898-0.983 (P<0.001), and the sensitivity and specificity of predicting the efficacy of interventional therapy for liver cancer were 91.84% and 91.55%. When the K^trans difference was greater than 0.250 min^-1, the AUC, sensitivity, and specificity were 0.933 (95%CI 0.872-0.970, P<0.001), 89.80%, and 88.73%. The differences of ADC and K^trans were more effective in predicting the postoperative efficacy of interventional surgery for liver cancer (both P<0.05). Conclusions　DCE-MRI combined with DWI has important clinical value in evaluating the treatment response of patients with liver cancer after interventional therapy. The parameter changes before and after interventional therapy can more intuitively reflect the efficacy, provide objective imaging data for the efficacy evaluation, and effectively guide the formulation of further treatment regimen for liver cancer.

Key words: Liver cancer, Dynamic contrast-enhanced magnetic resonance imaging, Diffusion weighted imaging, Interventional therapy, Application value

摘要： 目的　探讨动态增强磁共振成像（DCE-MRI）结合扩散加权成像（DWI）评估肝癌介入术后疗效的应用价值。方法　收集江汉大学附属湖北省第三人民医院2019年2月至2020年3月行介入治疗的120例肝癌患者的病例资料进行病例对照研究，按治疗疗效不同分为有效组71例与无效组49例，其中有效组男性52例，女性19例，年龄（53.16±8.47）岁；无效组男性31例，女性18例，年龄（53.21±8.69）岁。两组患者于肝癌介入治疗前、治疗3周后分别行肝脏常规磁共振成像（MRI）、DCE-MRI、DWI检查，测量表观扩散系数（ADC）值、转运常数（K^trans）、细胞外血管外空间的体积分数（Ve）、速率常数（Kep）、肿瘤体积。采用独立样本t检验和配对t检验比较治疗前后不同疗效组的ADC、K^trans、Ve、Kep肿瘤体积的差异，采用Pearson相关性分析ADC差值、K^trans差值、Ve差值、Kep差值与肝癌肿瘤体积差值的相关性，绘制受试者工作特征曲线（ROC）评价ADC、K^trans、Ve、Kep评估肝癌介入治疗疗效的价值。结果　与介入术前相比，介入术后肝癌患者ADC值升高为（1.23±0.14）×10^-3 mm²/s（t=10.970，P<0.05），K^trans降低为（0.18±0.07）min^-1（t=9.090，P<0.05），Kep降低为（0.31±0.06）min^-1（t=11.829，P<0.05），Ve值降低为（0.40±0.05）（t=6.252，P<0.05），肿瘤体积降低为（10.67±2.48）cm³（t=26.683，P<0.05）。治疗有效组ADC差值、K^trans差值、Kep差值、Ve差值、肿瘤体积差值分别为（0.35±0.08）×10^-3mm²/s、（0.24±0.06）min^-1、（0.47±0.12）min^-1、（0.46±0.13）、（10.57±2.34）cm³，均比无效组更高（t=17.525、12.355、16.285、13.835、22.747，均P<0.05）。ADC差值、K^trans差值、Kep差值、Ve差值与肿瘤体积差值呈正相关（r=0.474、0.495、0.375、0.365，均P<0.001），ADC差值、K^trans差值与肿瘤体积差值相关性最高。ADC差值>0.380×10^-3mm²/s时，ROC下面积（AUC）为0.953，95%置信区间（CI）为0.898～0.983（P<0.001），预测肝癌介入治疗疗效灵敏度为91.84%、特异度为91.55%；K^trans差值>0.250 min^-1时，AUC为0.933，95%CI为0.872～0.970，（P<0.001），预测灵敏度为89.80%、特异度为88.73%；ADC、K^trans差值预测肝癌介入术后疗效的效能均较高（均P<0.05）。结论　DCE-MRI联合DWI对肝癌介入术后患者治疗反应的评价有重要临床价值，介入术前后的参数变化值可较直观地反映疗效，为疗效评估提供客观的影像学数据，可有效指导肝癌患者进一步治疗方案的制定。

关键词: 肝癌, 增强磁共振, 扩散加权成像, 介入治疗, 应用价值