3.0T磁共振动态增强扫描对富血供肝肿瘤的诊断价值

目的      探讨3.0 T磁共振动态增强扫描对富血供肝肿瘤的鉴别诊断价值。方法      对40例富血供肝肿瘤（肝细胞癌26例,海绵状血管瘤12例,富血供转移瘤2例）相继进行MR平扫及3D FAME序列多期动态增强扫描,包括肝动脉期、门静脉期、平衡期及延迟期,观察病灶各期的强化特征。并利用动态强化自动分析软件及时间-信号强度曲线分析各种病变的曲线类型。结果      富血供肝细胞癌的时间-信号强度曲线分为两种类型：Ⅰ型（速升速降）、Ⅱ型(速升缓降)。26例肝细胞癌中69%（18/26)表现为Ⅰ型曲线类型, 31%（8/26）表现Ⅱ型曲线类型。肝血管瘤的动态增强曲线分为两种类型：Ⅰ型（缓升平坦型）、Ⅱ型（速升平坦型）。12例血管瘤中67%（8/12）表现为Ⅰ型曲线类型,33%(4/12)表现Ⅱ型曲线类型。2例富血供转移瘤表现为早期周边环状强化。结论      3.0 T磁共振动态增强扫描有助于富血供肝肿瘤的诊断及鉴别诊断。

Application of dynamic contrast-enhanced MRI in the diagnosis of hyper-vascular neoplasms of the liver

Objective     To evaluate the usefulness of  three-dimensional fast acquisition  plus multiphase enhanced fast GRE(3D FAME) sequence at 3.0T MR in diagnosing hyper vascular neoplasms of the liver. Methods     MR imaging was performed on 40 patients with hepatic neoplasms, including 26 hepatocellular carcinoma, 12  hemangioma  and  2 metastases. The imaging protocol consisted of a conventional plain scan and 3D FAME multi-phase dynamic scan (hepatic arterial,portal venous, equilibrium and delayed phases).Enhancement patterns were observed and  the time-signal intensity curve(TIC) was analyzed. Results      There were characteristic enhancement  patterns  identified among various types of hyper-vascular liver masses. The time-signal intensity curve reflected the hemodynamic changes of  the lesions. TIC of hepatocellular carcinoma was classified as: a) type Ⅰ: sharp incline and decline, which was seen in 69%（18/26) of cases; and b) type Ⅱ : sharp incline with flat decline, which was seen in 31%（8/26）of cases. TIC of hemangioma was classified as: a) type Ⅰ: flat incline  and plateau, which was seen in 67%（8/12）of cases; b)  type Ⅱ : sharp incline and plateau, which was seen in 33%(4/12) of cases. Two hyper-vascular metastases cases showed early peripheral-rim enhancement. Conclusion     3.0 T dynamic contrast enhanced MRI is very helpful in diagnosing different  hyper-vascular neoplasms of the liver.