purpose: to identify quantitative dynamic contrast-enhanced (dce)-mri perfusion parameters indicating tumor response of hepatocellular carcinoma (hcc) to transarterial chemoembolization (tace).
materials and methods: this prospective pilot study was approved by our institutional review board; written and informed consent was obtained for each participant. patients underwent dce-mri examinations before and after tace. a variable flip-angle unenhanced 3d mdixon sequence was performed for t1 mapping. a dynamic 4d mdixon sequence was performed after contrast injection for assessing dynamic signal enhancement. nonparametric analysis was conducted on the time-intensity curves. parametric analysis was performed on the time-concentration curves using a dual-input single-compartment model. treatment response according to liver reporting and data system (li-rads) v2018 was used as the reference standard. the comparisons within groups (before vs. after treatment) and between groups (nonviable vs. equivocal or viable tumor) were performed using nonparametric bootstrap taking into account the clustering effect of lesions in patients.
材料和方法：本项前瞻性试点研究经机构审查委员会批准；每位受试者都均签署了书面知情同意书。tace前后均行dce-mri检查。采用可变翻转角结合3d非增强mdixon序列进行t1映射。注射对比剂后使用动态4d mdixon序列评估动态信号增强。对时间-强度曲线进行非参数分析。采用双输入单室模型对时间-浓度曲线进行参数分析。治疗反应以肝脏影像报告和数据系统(li-rads) 2018版为参考标准。考虑到患者病变的聚集效应，采用非参数引导进行组内比较(治疗前 vs. 治疗后)和组间比较(肿瘤坏死组 vs. 不确定组或肿瘤存活组)。
results: twenty-eight patients with 52 hccs (size: 10-104mm) were evaluated. for nonviable tumors (n=27), time to peak increased from 62.5±18.2s before to 83.3±12.8s after treatment (p<0.01). for equivocal or viable tumors (n=25), time to peak and mean transit time significantly increased (from 54.4±24.1s to 69.5±18.9s, p<0.01 and from 14.2±11.8s to 33.9±36.8s, p=0.01, respectively) and the transfer constant from the extracellular and extravascular space to the central vein significantly decreased from 14.8±14.1 to 8.1±9.1s-1 after treatment (p=0.01).
结果：共评估了28例肝细胞癌(52个肿瘤，大小:10-104mm)患者。对于坏死肿瘤(n = 27)，峰值到达时间从治疗前的62.5±18.2s增加到治疗后的83.3±12.8 s (p< 0.01)。结果不确定组或肿瘤存活组(n = 25)峰值到达时间和平均通过时间显著增加(分别为：从54.4±24.1s增加至69.5±18.9s, p<0.01 ；从14.2±11.8s 增加至 33.9±36.8s, p=0.01)，细胞外和血管外空间向中央静脉的转移常数明显降低，从14.8±14.1至治疗后的 8.1±9.1s-1 (p=0.01)。
conclusion: this prospective pilot dce-mri study showed that time to peak significantly changed after tace treatment for both groups (nonviable tumors and equivocal or viable tumors). in our cohort, several perfusion parameters may provide an objective marker for differentiation of treatment response after tace in hcc patients.