真实稳态进动快速成像T_2加权序列在肝脏的应用价值

Evaluation of true FISP T_2 weighted MR imaging in the liver

目的 评价true FISP(真实稳态进动快速成像 )T2 WI序列在肝脏病变中的应用。方法45 2例临床拟诊肝胆疾患病人行横断面、冠状面或 (和 )矢状面true FISPT2 WI,对其中临床证实的 6 8例 (16 3个病灶 )进行评价 ,包括肝脏局灶病变的检出率、对比信噪比、肝内静脉的显示、周围脏器的显示及伪影等 ,并与TSE(快速自旋回波 )T2 WI进行比较。结果 对肝海绵状血管瘤和肝囊肿的检出率 ,true FISP与TSE相近 ;true FISP对肝脏恶性结节的检出率略低于TSE(P >0 0 5 ) ;true FISP的病灶对比信噪比低于TSE(P <0 0 5 ) ;对肝内静脉的显示 ,true FISP明显优于TSE(P <0 0 1) ;对解剖结构的显示 ,true FISP优于TSE(P <0 0 1)。结论 true FISPT2 WI用于肝胆病变的优点 :(1)有较高的空间分辨率和信噪比 ;(2 )肝内静脉显示清晰 ;(3)解剖结构的显示优于常规TSE序列。缺点 :(1)T2 对比较差 ,易遗漏肝脏实性结节 ;(2 )近膈面及胆囊区易出现磁敏感伪影 。

Objective To evaluate the application of true FISP T 2 weighted imaging in focal liver lesions. Methods True FISP T 2 weighted imaging were measured in 452 patients with a 1.5 T MRI scanner. Of which 68 cases with 163 proven hepatic lesions were evaluated for signal noise ratio (SNR), liver spleen contrast noise ratio (L S CNR), lesion detection, and definition of intrahepatic veins and artifacts. The results were compared with those from Turbo SE T 2 weighted imaging. Results True FISP and TSE showed similar ability in detecting cystic lesions. For detecting solid lesion, TSE was little better than true FISP ( P >0.05). True FISP T 2 *WI had fewer moving artifacts than TSE ( P <0.05). True FISP T 2 *WI showed intrahepatic veins much more clearly than TSE ( P <0.01). Conclusion While showing a lower L S CNR and detecting fewer solid lesions than TSE T 2WI, true FISP T 2 *WI has good SNR, little artifact and excellent demonstration of intrahepatic veins.