透视触发3D LAVA技术在肝实质病变及血管成像中的应用

Application of Fluoro-Trigger 3D LAVA technique for imaging hepatic lesions and blood vessels

目的探讨透视触发3DLAVA技术对肝实质病变及血管的显示情况。方法21例经手术病理或治疗后确诊的肝实质内病变的患者选入本次研究。应用1.5T扫描仪（GE Excite HD Twinspeed1.5T）。动脉期应用透视触发技术,以确保肝脏动脉早期的成功显示。对所有时相的主动脉、门脉、肝实质及病灶绘制信号强度-时间曲线,同时对动脉相及门脉相采用最大密度投影（MIP）,观察肝动脉及门脉的显示情况。结果21例病人均获得高质量6~8个时相的全肝图像。信号强度-时间曲线显示所有病例的门脉及肝实质均在第三个时相达到峰值,而不同病灶的信号强度-时间曲线各有特点,对诊断能够提供更多的帮助。MIP结合原图能清楚显示肝固有动脉的3~4级分支,对门脉系统的显示率达到100%。结论透视触发3DLAVA技术能够清楚显示肝实质病变的动态增强特点,能够清楚显示肝动脉、门脉的分支及其与病灶的关系。

Objective To investigate the efficacy of fluoro-trigger 3D LAVA technique for imaging hepatic lesions and vessels. Methods Twenty-one patients with hepatic lesions confirmed by pathologic results or after treatment were included in this study. 3D LAVA multi-phase （6-8 phase） dynamic MR imaging was performed with 1.5T MR imaging systems （GE Excite HD Twinspeed 1.5T）. To successfully display the early-arterial phase, the arterial-phase was monitored by fluoro-trigger technique. Signal intensity-time curves were derived from aorta, portal vein, hepatic parenchyma and hepatic lesions for all patients. To evaluate the ability for depicting the arterial and the portal-vein, the arterial and portal phase were reconstructed using 3D maximum intensity projection （MIP）. Results High quality imaging of whole liver with 6-8 phases was obtained in all of 21 patients. The signal intensity-time curves showed the peak enhancement of hepatic parenchyma was at third phase in all of 21 patients, there were different features of signal intensity-time curves for the various hepatic lesions, this may be more helpful to diagnosis. When combine the MIP and source images together, the 3-4 order branches of proper hepatic artery were well defined in all of 21 patients, concomitant branches portal venous system were shown by 100%. Conclusion Fluoro-trigger 3D LAVA technique could define the features of the dynamic enhancement of the hepatic lesions clearly, and could also depict hepatic vessels and the relationship between hepatic lesions, hepatic artery and portal veins very well.