Quan Xian-Yue, Sun Xi-Jie, Yu Zhi-Jian, Tang Ming
Imaging Center, Affiliated Zhujiang Hospital of Southern Medical University, Guangzhou 510282, China.
Hepatobiliary Pancreat Dis Int. 2005 Aug;4(3):406-9.
Diffusion-weighted imaging (DWI) as a new technique of magnetic resonance imaging (MRI) is used to detect focal hepatic lesions. This study was designed to evaluate the significance of DWI to differentiate focal hepatic lesions less than 3 cm in diameter by the quantitation of apparent diffusion coefficient (ADC) values.
DWI using 1.5T MRI scanner unit was performed with a spin-echo single-shot echo planar imaging (EPI) in 56 cases of small focal hepatic lesions, including hepatocellular carcinoma (11), hepatic metastatic tumor (15), hepatic cavernous hemangioma (14), and hepatic cyst (16). The ADC values of these lesions were calculated respectively. The ratios of the ADC values of lesion/liver in hepatocellular carcinomas and hepatic metastatic tumors were also estimated.
The mean ADC values (mm2/s) were (0.93+/-0.06) x 10(-3) in hepatocellular carcinomas, (1.09+/-0.18) x 10(-3) in hepatic metastatic tumors, (1.95+/-0.38) x 10(-3) in hepatic cavernous hemangiomas, and (3.18+/-0.33) x 10(-3) in hepatic cysts. The ratios of ADC values of lesion/liver were 0.90+/-0.06 and 1.15+/-0.14 in hepatocellular carcinoma and hepatic metastatic tumors respectively, which were significantly different (P < 0.05).
The measurement of ADC values and the ratios of ADC values of lesion/liver are helpful in MR diagnosis and differentiation of focal hepatic lesions.
扩散加权成像（DWI）作为磁共振成像（MRI）的一项新技术，用于检测肝脏局灶性病变。本研究旨在通过表观扩散系数（ADC）值的定量分析，评估DWI对鉴别直径小于3 cm的肝脏局灶性病变的意义。
采用1.5T MRI扫描仪，对56例肝脏小局灶性病变患者行自旋回波单次激发回波平面成像（EPI）序列的DWI检查，其中包括肝细胞癌11例、肝转移瘤15例、肝海绵状血管瘤14例、肝囊肿16例。分别计算这些病变的ADC值，并估算肝细胞癌和肝转移瘤的病变/肝脏ADC值之比。
肝细胞癌的平均ADC值（mm2/s）为（0.93±0.06）×10-3，肝转移瘤为（1.09±0.18）×10-3，肝海绵状血管瘤为（1.95±0.38）×10-3，肝囊肿为（3.18±0.33）×10-3。肝细胞癌和肝转移瘤的病变/肝脏ADC值之比分别为0.90±0.06和1.15±0.14，两者差异有统计学意义（P<0.05）。
测量ADC值及病变/肝脏ADC值之比有助于肝脏局灶性病变的磁共振诊断及鉴别诊断。
