中文摘要：

目的探讨CT能谱成像在鉴别小肝癌和小血管瘤中的应用价值。方法60例肝脏占位病变患者，其中小肝癌（ small hepatocellular carcinoma, SHCC）30例，肝小血管瘤（small hepatic hemangioma,SHH）30例，均行宝石CT双能量扫描，获得动脉期（arterial phase，AP）和门脉期（portal venous phase，PP）的能谱系列图像。测量病灶、正常肝组织和腹主动脉的能谱参数，并计算不同能量水平下病灶一肝脏对比噪声比（contrast to noise ratio,CNR），标准化碘浓度（normalized iodine concentration, NIC）和病灶与正常肝组织碘浓度比值（1esion-to—normal hepatic tissue ratio，LNR），对上述结果进行独立样本t检验。结果小肝癌和小血管瘤的动脉期最佳单能量均为50keV，门脉期最佳单能量分别为70keV、50keV；动脉期最佳CNR分别为3．58±2．12、10．03±2．72，门脉期最佳CNR分别为1．79±0．92、3．08±2．38；动脉期NIC分别为（O．25士0．08）mg／mL，（0．46土0．18）mg／mL，门脉期N1C分别为（0．52±0．15）mg／mL和（0．87±0．25）mg／mL；动脉期LNR值分别为2．97±0．50，6．01±2．29，门脉期LNR值分别为0．98±0．18，1．58土0．38。小肝癌的动脉期和门脉期NIC和LNR值均低于小血管瘤。两者2期的NIC、LNR、钙（脂肪）浓度和脂肪（钙）浓度均有统计学差异（P〈0．05），但其水（碘）浓度在2期中均无统计学差异（P〉0．05）。结论CT能谱成像的单能量图像、碘基图像和碘物质定量分析对小肝癌和小血管瘤的检出和鉴别诊断有价值。

英文摘要：

Objective To explore the value of spectral CT imaging in the differential diagnosis of small hepatocellular carcinoma and small hepatic hemangioma. Methods 60 patients with hepatic lesions, including 30 small hepatocellular carcinoma and 30 small hepatic hemangioma, underwent dual energy scans to obtain spectral serial images for the arterial phase and portal venous phase. The spectral parameters of lesions, normal hepatic tissue and the aorta were measured. Then, the lesion-liver contrast to noise ratio in the different energy levels, normalized iodine concentration and the lesion-normal hepatic tissue iodine concentration ratio were calculated. The results were analyzed with independent samples t test. Results The optimal monochromatic energy of small hepatocellular carcinoma and small hepatic hemangioma both were 50 keV during the AP and 70 keV and 50 keV, respectively, during the PP. The optimal CNR were 3.58±2.12 and 10.03±2.72, respectively, during the AP and 1.79±0.92 and 3.08±2.38, respec tively, during the PP. The NIC were （0.25±0.08）mg/mL and （ 0.46±0.18 ）mg/mL , respectively , during the AP and （0.52±0.15）mg/mL and （0.87±0.25）mg/mL, respectively, during the PP. The LNR were 2.97±0.50 and 6.01±2.29, respectively, during the AP and 0. 98±0.18 and 1.58±0.38, respectively, during the PP. The NIC and LNR for SHCC were smaller than those of SHH. There were significant differences in NIC, LNR, calcium（fat） and fat（calcium） concentration during the AP and PP betweenSHCC and SHH（P〈0.05）. There were no significant differences in the water （iodine） concentration during the AP and PP（P〉0.05）. Conclusion The use of spectral CT with monochromatic images , iodine-based material decomposition images and the quantitative analysis of iodine concentrations are useful for the detection and differential diagnosis of SHCC and SHH.