动态对比增强磁共振成像Ktrans与HPI纹理分析对肝细胞癌及结直肠癌肝转移瘤的鉴别价值

目的探讨经动态对比增强磁共振成像（DCE-MRI）获取的渗透性参数容积转运常数（Ktrans）和灌注性参数动脉灌注指数（HPI）的纹理分析对肝细胞癌和结直肠癌肝转移瘤的鉴别诊断能力。 方法选取2015年12月至2017年1月于大连医科大学附属第一医院行肝脏动态增强磁共振（DCE-MRI）患者28例，经手术病理证实的肝细胞癌（HCC）15例16个病灶，手术证实结直肠癌且影像随诊证实为肝转移瘤（HM）13例19个病灶。扫描序列包括双回波T1WI、T2WI、4个肝脏快速容积成像（LAVA）非注射药物预扫描序列（偏转角3°、6°、9°、12°）及动态增强LAVA采用3D序列，TR/TE：3.1 ms/1.3 ms、偏转角12°，共采集30期，每期扫描6 s间隔1 s，扫描时间3.14 min。使用Omni-Kinetics软件的exchange模型计算Ktrans值及HPI的灰度共生矩阵参数包括：能量（energy）、熵（entropy）、惯性矩（inertia）、相关性（correlation）、逆差矩（IDM）、聚类萌（cluster shade）、聚类突（cluster promince）。由2位观察者进行数据测量，使用组内相关系数（ICC）法检验2位观察者测量数据的一致性。采用t检验或Wilcoxon秩和检验比较两者间各参数差异。 结果HCC的Ktrans均值高于HM，P=0.02；HCC和HM间HPI的均值无差异；灰度共生矩阵参数Ktrans值：HCC的聚类萌低于HM，而能量、熵、惯性矩、相关性、逆差矩、聚类突在2组病变间差异无统计学意义；HPI值：HCC的惯性矩低于HM，HCC的相关性高于HM，而能量、熵、逆差矩、聚类萌、聚类突间差异无统计学意义。 结论Ktrans和HPI的纹理参数对于肝细胞癌和结直肠癌肝转移瘤的鉴别具有重要的指导作用。

Differential diagnosis of hepatocellular carcinoma and hepatic metastases from colorectal cancer using texture features derived from DCE-MRI

ObjectiveTo investigate the value of Ktrans (the volume transfer constant from plasma to the extracellular extravascular space), HPI (hepatic arterial perfusion index), and their texture features derived from dynamic contrast-enhanced MRI (DCE-MRI) in the differentiation of hepatocellular carcinoma (HCC) and hepatic metastases from colorectal cancer (HM). MethodsTwenty-eight patients with HCC or HM who underwent DCE-MRI between December 2015 and January 2017 at the First Affiliated Hospital of Dalian Medical University were included. Among them, 15 patients had HCC (16 lesions) and 13 had HM (19 lesions), which were confirmed by imaging follow-up or by surgery and pathology. DCE-MRI images were acquired using the liver acquisition with volume acceleration (LAVA) sequence which consisted of multi-flip angle (FA) contrast free image acquisition (FA=3°, 6°, 9°, and 12°) for T1 mapping, and a continuous multiphase acquisition (FA=12°) to capture contrast medium wash-in and wash-out. The flip and dynamic images were acquired using the same parameters but different FA: TR/TE, 3.1/1.3 ms; with 30 phases, 6 seconds each phase and a total of 3.14 min. The t-test or the Wilcoxon test was used to compare the differences of the texture features. ResultsMean value of K_trans of HCC was significantly higher than that of HM (P=0.020). Mean values of HPI had no statistical difference between the two groups. The cluster shade from Ktrans and inertia from HPI of HCC were lower than that of HM. The inertia from HPI of HCC were lower than that of HM. The correlation from HPI of HCC was statistically significantly higher than that of HM. There were no differences between HCC and HM regarding other texture features. ConclusionTexture features of Ktrans and HPI can provided an important guiding role in clinical work.