扩散加权成像对肝局灶病变检出的多中心研究

Detection of Focal Liver Lesions with Diffusion Weighted Imaging: Results of A Multi-center Clinical Trial

目的评价扩散加权成像(DWI)在肝局灶性病变(FLL)检出中的价值。资料与方法选取205例FLL患者共310个病灶,均行T2WI、动态增强(DCE)及DWI检查,b值分别为100 s/mm2及600 s/mm2,2名评估者阅读每个病例所有序列图像,并对各序列对病灶的检出进行评分。分析2名评估者评估结果的一致性,比较各序列对病变检出的信心评分以及各序列对各类病变的检出率。结果对于T2WI、高b值DWI、低b值DWI、DCE序列的检出信心评分,2名评估者的一致性为一般或好(Kappa=0.71、0.85、0.82、0.64,P<0.05)。对FLL检出信心的平均评分,高b值DWI及低b值DWI均明显高于T2WI(P<0.01),但都低于DCE(P<0.01)。DWI对FLL的检出评分及检出率均明显高于T2WI(86.5%比70.3%,P<0.01),但低于DCE(91.6%,P<0.05);对直径≤2 cm的恶性小病灶,DWI的检出率显著高于T2WI(P<0.01),而与DCE相似(P>0.05),DWI+DCE的检出率明显高于DWI或DCE(P<0.01)。结论 DWI对肝局灶性病变的检出率高于T2WI,并可提高DCE对恶性小病灶的检出,应作为肝脏MRI检查的常规序列。

Purpose To investigate the role of diffusion weighted imaging（DWI） in the detection of focal liver lesions（FLL）. Materials and Methods T2 WI, dynamic contrast enhancement（DCE） and DWI（b=100 s/mm2 and 600 s/mm2 respectively） were performed in 205 patients with 310 FLLs. All images were read by two reviewers to determine the detection of FLLs and score the confidence. The consistency of the results given by the two reviewers was evaluated. The confidence scores between different sequences and the detection rate of different sequences were also compared. Results The consistency of the two reviewers was excellent or good in T2 WI, high b value DWI, low b value DWI, and DCE（Kappa=0.71, 0.85, 0.82 and 0.64, P〈0.05）. As to the confidence score of lesion detection, high b value DWI and low b value DWI were both significantly higher than T2WI（P〈0.01）, but both were lower than DCE（P〈0.01）. DWI yielded higher score and detection rate for detecting FLLs than T2WI（86.5% vs. 70.3%, P〈0.01）, but lower than DCE（91.6%, P〈0.05）. For small malignant lesions（ ≤ 2 cm in diameter）, DWI showed similar detection rate with DCE（P〈0.05）, but higher than T2WI（P〈0.01）. The combination of DWI and DCE detected more small malignant lesions than DWI or DCE alone（P〈0.01）. Conclusion DWI can detect more FLLs than T2 WI, and can help DCE detect small malignant FLLs. Therefore DWI is suggested to be included in the routine protocol of liver MRI examination.