呼吸导航回波触发心脏MRI黑血对比序列的应用

目的 评价呼吸导航同波触发心脏黑血对比快速sE(FSE)序列的应用优势.方法 将呼吸导航回波触发技术与黑血对比FSE序列(NAV-FSE)结合,11名志愿者和5例患者在自由呼吸状态下完成扫描,同时使用相同参数的屏气黑血对比序列(BH-FSE)作为对比,使用t检验比较两者在采样效率、图像锐利度的差别.结果 NAV-FSE能对所有受检者完成全部检查,1名志愿者和3例患者不能屏气配合完成BH-FSE检查;当回波链长度(ETL)分别为24、16、8时,NAV-FSE的成像效率分别为(42.95±11.50)%、(56.14±11.40)%、(55.25±14.70)%.图像锐利度在ETL=16和24时,NAV-FSE(分别为0.43±0.02、0.36±0.02)和BH.FSE(分别为0.36±0.03、0.35±0.02)的差异有统计学意义(t值分别为4.26、5.53,P值均<0.05).NAV.FSE还可以设置更短的ETL而尤需考虑屏气的限制.结论 NAV-FSE可以回避心脏MR检查的屏气限制,并可以通过改变参数达到提高图像质量的目的 .

Clinical application of respiratory navigator echo triggered black blood contrast cardiac MRI

Objective To investigate the application of respiratory navigator echo triggered black blood contrast FSE in cardiac MRI. Methods The respiratory navigator echo trigger technique combining with black blood FSE (NAV-FSE) was tested on 11 volunteers and 5 patients in free breathing,using breath-hold FSE (BH-FSE) with the same imaging protocals as control. The imaging efficiency and the image sharpness were compared between NAV-FSE and BH-FSE and t-test was used for the statistics. Results All NAV-FSE acquisitions were completed in sixteen subjects while 4 BH-FSE acquisitions failed because of poor breath holding. The efficiencies of NAV-FSE were (42. 95±11.50)%, (56. 14±11.40)% and (55.25± 14. 70)% when echo train length (ETL) were 24, 16 and 8, respectively. When ETL were 16 and 24, the sharpness of NAV-FSE ( 0. 43±0. 02 vs 0. 36±0. 02 ) and BH-FSE ( 0. 36±0. 03 vs 0. 35±0. 02 ) were statistically different (t =4. 26, 5. 53 ,respectively; P <0. 05). NAV-FSE could have a shorter ETL setting without consideration of breath holding. Conclusion The navigator echo trigger technique could be compatible with black blood contrast FSE to image the heart without the restriction of breath holding and it allows to optimize the parameters to improve the image quality.