目的利用磁共振扩散加权成像 (DWI)对局灶性肝脏病变进行定量分析， 探讨其在局灶性肝脏病变中的应用价值。 方法 应用SE-EPI DWI(b＝500s/mm2 )序 列，对局灶性肝脏病变111例(原发性肝 细胞癌35例，周围型胆管细胞癌7例，转 移瘤25例，局灶性结节增生3例，血管瘤 22例，囊肿19例)进行扫描，测量病变的 表观弥散系数(ADC)值，比较不同疾病ADC 值的差异。结果 b值选用500s/mm2 时， 正常肝脏的ADC值为(1.49±0.14)×10-3 mm2 /s，原发性肝细胞癌、胆管细胞癌、 转移瘤、局灶性结节增生、血管瘤和 囊肿的ADC值分别为(0.93±0.14)×10-3 m m 2 /s、(0.97±0.15)×10 - 3 m m 2 / s、(1.06±0.17)×10 - 3 m m 2 /s、 (1.53±0.29)×10 - 3 m m 2 /s、 (2.18±0.23)×10 - 3 m m 2 /s和 (3.15±0.21)×10-3mm2 /s。肝癌和转移瘤 的ADC值小于正常肝脏(P＜0.01),血管瘤 和囊肿的ADC值大于肝脏(P＜0.01)。局 灶性结节增生与肝脏的ADC值之间、肝癌 与转移瘤的ADC值之间无统计学差异(P＞ 0.05)。结论 磁共振弥散成像及ADC值测 定，能较准确的判断局灶性肝脏病变的性 质，对其诊断及鉴别诊断有一定价值。

Objective To evaluate the value of diffusion-weighted imaging (DWI)in the diagnosis of focal hepatic lesions by quantitative analysis. Methods A total of 111 patients with focal hepatic lesions(including 35 cases of hepatocellular carcinoma, 7 cases of peripheral cholangiocarcinoma,25 cases of hepatic metastatic tumors,3 cases of focal nodal hyperplasia,22 cases of hepatic hemangiomas and 19 cases of hepatic cysts)were examined by MRI SE-EPI and DWI(b=500/mm2 ) sequence, to measure and analyze the difference of apparent dispersion conficient(ADC) values. Results When b=500s/ mm2 ,the average ADC value of normal hepatic tissue was(1.49±0.14)×10-3mm2 /s， the average ADC values of hepatocellular carcinoma、metastatic tumor、focal nodal hyperplasia、hemangioma and cyst were (0.93±0.14)×10-3mm2 /s, (0.97±0.15)×10- 3 mm2 /s, (1.06±0.17)×10-3mm2 /s, (1.53±0.29)×10-3mm2 /s, (2.18±0.23)×10-3mm2 / s and (3.15±0.21)×10-3mm2 /s. The ADC value of hepatocellular carcinoma and metastatic tumor lower than that of normal hepatic tissue(P＜0.001).The ADC value of hemangioma and cyst higher than that of normal hepatic tissue(P＜0.001).The ADC value had no significant differences between focal nodal hyperplasia and normal hepatic tissue, hepatocellular carcinoma (P＞0.05). Conclusion According to DWI and ADC values, the quality of hepatic lesions can be exactly diagnosed, which has a certain value in the diagnosis and differential diagnosis of focal hepatic leions.