肝肿瘤的MRI诊断

THE MRI IN THE DIAGNOSIS OF HEPATIC TUMORS

本文对２０８例常见肝肿瘤（肝癌１００例，血管瘤６２例，肝囊肿４６例）的磁共振（ＭＲＩ）表现进行病变形态学和信号强度分析。Ｔ１Ｗ图象上，３种肿瘤多为偏低信号强度；Ｔ２Ｗ图象上表现为中高信号强度影。利用多回波序列扫描，观察到ＴＥ＝２０～４０ｍｓ时，肝囊肿的信号强度低于肝癌和肝血管瘤：ＴＥ＝８０ｍｓ以上时，肝癌的信号强度明显低于其它２种病变。Ｇｄ－ＤＴＰＡ增强后，各自也有不同的强化形式，为肝脏肿瘤提供了又一有效的影像方法。本研究认为常规扫描自旋回波Ｔ１Ｗ和含有２个回波的Ｔ２Ｗ序列基本上可满足肝脏病变的诊断要求。建议Ｔ２Ｗ的２个回波时间ＴＥ为３０ｍｓ，１２０ｍｓ。如常规扫描上述序列仍不能确定诊断，可作多回波序列、Ｔ２Ｗ脂肪压抑或Ｔ１增强等进一步检查。

he MRI analyses of 208 cases of hepatic tumor were made , including 100 cases of liver carcinoma, 62 cases of hemangioma , and 46 cases of hepatic cyst. In T1W imaging ,all tumors showed low intensity;and in T2W showed mid-high intensity. Using multi-echo sequence,the hepatic cysts showed lower intensity than the other two when was TE=20～40ms. when TE was higher then 80 ms , the liver carcinoma signal intensity decreased obviously as compared with the hepatic hemangioma and cyst. MRI is a sensitive imaging technique for differential diagnosis among the hepatic tumors. It is suggested that T1W and T2W with two echoes se- quences can be used for the routine examination for the liver MRI. In case the routine exami- nation for the liver MRI. In cases of uncertainty , the multi-echo , T2W with fat supression and Gd-DTPA enhanced T1W sequences should be used with respect to the patient's situa- tion.