Prakken Niek Hendrik Jan, Vonken Evert-Jan P A, Velthuis Birgitta K, Doevendans Pieter A F M, Cramer Maarten-Jan M
Department of Radiology, University Medical Centre, Utrecht, The Netherlands.
Int J Cardiovasc Imaging. 2006 Jun-Aug;22(3-4):477-87. doi: 10.1007/s10554-005-9053-8. Epub 2006 Mar 15.
Current clinical full MR angiography with multiple breathhold multiple thin slab acquisition (MTS) is difficult and arduous. This study describes the optimisation of the whole heart free - breathing balanced turbo field echo (B-TFE) protocol. A high-resolution image of the whole heart is produced in less or comparable time to MTS acquisition and allows for reconstruction afterwards to visualise the individual coronary arteries. The scan is easily performed because the volume has to be targeted only once.
Eighteen healthy adults without a history of cardiovascular disease underwent free-breathing 3D MR angiography with the B-TFE protocol. The whole-heart data set was reformatted in identical orientations in all subjects to visualise the major coronary arteries.
Vessel length, signal and contrast to noise ratio were determined and compared for each vessel.
Mean visible vessel lengths were 116 mm for the right, 102 mm for the left main and left descending and 76 mm for the left circumflex coronary artery. The average signal to noise ratio was 7.5 and contrast to noise ratio was 4.9. Because of the need for synchronised cardiac and respiratory triggering the coronaries could not be judged in 25% of the subjects.
The optimised B-TFE protocol had equal judgeability and vessels could be judged over longer contiguous distances compared to earlier implementations of the B-TFE protocol. We conclude whole heart free breathing navigator-gated and slice-tracked 3D coronary MR angiography with use of the adjusted B-TFE protocol is possible, but still suboptimal for clinical use.
当前采用多次屏气多薄层采集（MTS）的临床全磁共振血管造影术操作困难且艰巨。本研究描述了全心自由呼吸平衡式涡轮场回波（B-TFE）协议的优化。与MTS采集相比，在更短或相当的时间内生成了全心的高分辨率图像，并允许随后进行重建以可视化各条冠状动脉。该扫描操作简便，因为只需对感兴趣容积进行一次定位。
18名无心血管疾病史的健康成年人接受了采用B-TFE协议的自由呼吸三维磁共振血管造影检查。对所有受试者的全心数据集进行相同方向的重新格式化，以可视化主要冠状动脉。
测定并比较每条血管的血管长度、信号及对比噪声比。
右冠状动脉平均可见长度为116毫米，左主干和左前降支为102毫米，左旋支冠状动脉为76毫米。平均信噪比为7.5，对比噪声比为4.9。由于需要心脏和呼吸同步触发，25%的受试者无法对冠状动脉进行评估。
优化后的B-TFE协议具有相同的可评估性，与早期的B-TFE协议相比，血管可在更长的连续距离上进行评估。我们得出结论，使用调整后的B-TFE协议进行全心自由呼吸导航门控和层面跟踪三维冠状动脉磁共振血管造影是可行的，但仍不适合临床应用。
