CT能谱成像鉴别肝癌和肝脏局灶性结节增生的临床价值

目的探讨CT能谱成像在鉴别肝癌和肝局灶性结节增生（FNH）中的应用价值。方法回顾性分析46例肝脏占位性病变患者（肝癌32例，FNH14例）行64层CT双期能谱扫描结果。测量病灶、正常肝组织和腹主动脉的能谱参数，对比分析两种占位性病变间不同能量水平下病灶-肝脏对比噪声比（CNR）、标准化碘浓度（NIC）、病灶与正常肝组织碘浓度比值（LNR）及病灶动脉期和门静脉期碘浓度的差异（ICD）等。结果除部分能量点外，肝癌和FNH在不同能量水平下的CNR随着单光子能量的增加而减小。肝癌和FNH的动脉期最佳CNR分别为3.6±1.1和8.3±2.7，门静脉期最佳CNR分别为1.8±0.3和1.1±0.2；肝癌和FNH动脉期NIC分别为0.3±0.1和0.4±0.1，门静脉期NIC分别为0.5±0.1和0.9±0.2；动脉期LNR分别为3.0±0.5和6.2±1.0，门静脉期LNR分别为1.0±0.1和1.2±0.3；动脉期和门静脉期ICD值分别为0.4±0.1g/L和1.2±0.3g/L。肝癌动脉期和门静脉期的NIC、LNR和ICD值均低于FNH，差异均有统计学意义（NIC比较，t值分别为-3.196、-6.518；LNR比较，t值分别为-12.911、-3.260；ICD比较，t值为-2.754，P均＜0.05）。动脉期LNR鉴别肝癌和FNH的敏感度和特异度最高，均为100%。结论 CT能谱成像分析对肝癌和FNH的检出和鉴别诊断有一定的价值，能提高检出效能和诊断准确性。

Spectral CT imaging in differential diagnosis of hepatocellular carcinoma and focal nodular hyperplasia

Objective To assess the clinical value of spectral CT imaging in differential diagnosis of hepatocellular carcinoma（HCC）and focal nodular hyperplasia（FNH）. Methods Serial spectral images from forty-six patients with hepatic mass （32 with HCC and 14 with FNH）received dual-phase CT spectral imaging were analyzed retrospectively. The spectral parameters of the mass, the normal hepatic tissues and the aorta were obtained. The contrast-to-noise ratio （CNR）of mass-to-liver under different energy levels, the normalized iodine concentration （NIC）,the mass-to-liver iodine concentration ratio （LNR）and the iodine concentration difference （ICD）between the arterial phase and the portal vein phase were calculated. All the measurements were analyzed with two-sample t test and ROC curve. Results The CNR of HCC and FNH under different energy decreased with increased single photon energy except for some energy points. At the arterial phase,the optimal CNR was 3.6±1.1 for HCC and 8.3±2.7 for FNH,and in HCC, the NIC and LNR were 0.3±0.1 and 3.0±0.5,respectively, which were significantly lower than those in FNH（NIC was 0.4±0.1,t=-3.196;LNR was 6.2±1.0,t=-12.911,P〈0.05）;At the portal vein phase,the optimal CNR was 1.8±0.3 for HCC and 1.1±0.2 for FNH,and in HCC,the NIC and LNR were 0.5±0.1 and 1.0±0.1,respectively,which were also significantly lower than those in FNH （NIC was 0.9±0.2,t=-6.518;LNR was 1.2±0.3,t=-3.260,P〈0.05）;The ICD in HCC （0.4±0.1）was also lower than that in FNH （1.2±0.3g/L,t=-2.754,P〈0.05）;LNR in the arterial phase had the higher sensitivity（100%）and specificity（100%） in differentiating HCC from FNH. Conclusion Spectral CT imaging is useful in differentiating HCC from FNH with a good efficacy and accuracy.