弥散加权成像在肝脏占位性病变中的应用价值

1、弥散加权成像在肝脏占位性病变中的应用价值            弥散加权成像在肝脏占位性病变中的应用价值    2008-5-9 12:14:59                        

2、60;                                     作者：强永乾，郭佑民，孙兴旺，张月浪      【关键词】  弥散加权成像；表观弥散系数；癌,肝细胞；血管瘤；

3、肝囊肿    Clinical application value of diffusionweighted imaging in the diagnosis of focal spaceoccupying lesions in liver    【Abstract】 AIM: To study the diagnosis and differential diagnosis value of diffusionweighted imaging (DWI) and apparent diffusion coeffi

4、cient（ADC）in hepatocellular carcinoma(HCC), hepatic hemangiomas and hepatic cysts. METHODS: DWI was performed in 104 cases with focal spaceoccupying lesions in liver (including 35 HCC, 36 hepatic hemangiomas and 33 hepatic cysts). All ADC values were measured by using Philips soft package on the ADC

5、 imaging at the different b values. RESULTS: Most of HCC showed complex signals on DWI. The parenchyma part of HCC showed high signals, but the necrotic part showed low signals. The edge of tumors was clearly showed. The signals of the lesions were lessened when b value was increased. The hepatic cy

6、st showed the homogenous low signals on DWI, and the signals were obviously decreased or vanished when b value was increased. Hemangiomas  showed homogenous high signal on DWI, and the signal intensity was between HCC and hepatic cysts. The signal intensity on ADC was totally opposite to that o

7、n DWI. When the b value were 300, 1000 and 1500 s/mm2, the ADC values (1×10-3 mm2/s) of HCC, hemangioma and hepatic cyst were 1.163±0.206, 0.898±0.155, 0.803±0.140; 2.207±0.463, 1.723±0.303, 1.565±0.236; 3.522±0.340, 2.885±0.289, 2.332±0.237, respect

8、ively. There were significant differences among them （P<0.01）. The ADC value in the same lesion showed significant differences at different b values. When the b values was 1000 s/mm2, the ADC threshold between malignant and benign lesions was 1.274×10-3 mm2/s, the sensitivity and the specifi

9、city were 96.99% and 97.10%, respectively .The decreasing degree of the ADC value was different in different lesions. CONCLUSION: The hepatic spaceoccupying lesion can be easily diagnosed and distinguished according to DWI, ADC value and their changing characteristics. So, DWI has an important clini

10、cal value in the diagnosis of hepatic focal spaceoccupying lesion.    【Keywords】  diffusion weighted imaging (DWI); apparent diffusion coefficient (ADC); carcinoma, hepatocellular; hemangioma; hepatic Cyst    【摘要】 目的： 探讨弥散加权成像(diffusionweighted imaging, D

11、WI)及表观弥散系数（apparent diffusion coefficient, ADC）值在原发性肝癌、肝血管瘤及肝囊肿中的诊断与鉴别诊断价值. 方法： 对104例肝脏占位性病变（其中包括35例原发性肝癌、36例肝血管瘤、33例肝囊肿）进行磁共振DWI，在ADC图上利用Philips公司数据测量软件包直接测量不同值时肝脏占位性病变的ADC值. 结果： 原发性肝癌在DWI上大多数表现为混杂信号，实质部分为高信号，坏死囊变部分为低信号，边界非常清楚，随着b值的增加病灶信号稍有下降；肝囊肿在DWI表现为均匀的低信号，随着b值的增加病灶的信号明显下降甚至消失；肝血管瘤在DWI上信号大多数表现为均

12、匀的稍高或等信号，随着b值的增加信号强度降低介于肝癌与肝囊肿之间. ADC图上信号强度表现与DWI图正好相反. b值为300, 1000和1500 s/mm2时，原发性肝癌、肝血管瘤、肝囊肿ADC值分别为（单位×10-3 mm2/s）1.163±0.206, 2.207±0.463, 3.522±0.340;  0.898±0.155, 1.723±0.303, 2.885±0.289和0.802±0.140, 1.321±0.149, 2.332±0.237. 经统计学处理原发性肝癌

13、、肝血管瘤、肝囊肿的ADC值差异有统计学意义（P<0.01）；不同b值下同一种病变的ADC值存在明显差异. b值为1000 s/mm2时，良恶性病变的分界值为1.274×10-3 mm2/s，敏感度96.99%，特异度97.10%；随着b值的增大，病变的ADC值下降，不同病变其ADC值下降的程度不同. 结论： 依据磁共振弥散成像的DWI图像、ADC值及其变化规律，能比较准确的判断肝脏占位病变的性质，对肝脏占位性病变的诊断及鉴别诊断有一定价值. 【关键词】  弥散加权成像；表观弥散系数；癌，肝细胞；血管瘤；肝囊肿    0引言    弥散加权成像(diffusion weighted imaging, DWI)是一种新的MR功能成像技术，其在中枢神经系统的应用比较成熟，对超急性期脑梗塞的诊断价值已经得到肯定1-2，然而DWI在腹部的应用尚处于探索阶段. 1994年Muller等认为活体测量腹部脏器的表观弥散系数（apparent diffusion coefficient, ADC）值有利于疾病的鉴别诊断. 随后，国