Turku PET Centre, PO BOX 52, 20521, Turku, Finland.
Eur J Nucl Med Mol Imaging. 2010 Mar;37(3):505-16. doi: 10.1007/s00259-009-1252-4. Epub 2009 Sep 30.
Both respiratory and cardiac motions reduce image quality in myocardial imaging. For accurate imaging of small structures such as vulnerable coronary plaques, simultaneous cardiac and respiratory gating is warranted. This study tests the feasibility of a recently developed robust method for cardiac-respiratory gating. List-mode data with triggers from respiratory and cardiac cycles are rearranged into dual-gated segments and reconstructed with standard algorithms of a commercial PET/CT scanner. Cardiac gates were defined as three fixed phases and one variable diastolic phase. Chest motion was measured with a respiratory gating device and post-processed to determine gates. Preservation of quantification in dual-gated images was tested with an IEC whole-body phantom.
Minipig and human studies were performed to evaluate the feasibility of the method. In minipig studies, a coronary catheter with radioactive tip was guided in coronary artery for in vivo and ex vivo acquisitions. Dual gating in humans with suspected cardiac disorders was performed using 18-F-FDG as a tracer.
The method was found feasible for in vivo imaging and the radioactive catheter tip was better resolved in gated images. In human studies, the dual gating was found feasible and easy for clinical routine. Maximal movement of myocardial surface in cranio-caudal direction was over 20 mm. The shape of myocardium was clearly different between the gates and papillary muscles become more visible in diastolic images.
The first clinical experiences using robust cardiac-respiratory dual gating are encouraging. Further testing in larger clinical populations using tracers designed especially for plaque imaging is warranted.
呼吸和心脏运动都会降低心肌成像的图像质量。为了准确成像小结构，如易损的冠状动脉斑块，有必要同时进行心脏和呼吸门控。本研究测试了一种新开发的稳健心脏-呼吸门控方法的可行性。使用来自呼吸和心脏周期的触发的列表模式数据被重新排列成双门控段，并使用商业 PET/CT 扫描仪的标准算法进行重建。心脏门被定义为三个固定相位和一个可变的舒张相位。胸部运动使用呼吸门控设备进行测量，并进行后处理以确定门。使用 IEC 全身体模测试了双门控图像中的定量保留。
进行了小型猪和人体研究，以评估该方法的可行性。在小型猪研究中，放射性尖端的冠状动脉导管被引导到冠状动脉中进行体内和体外采集。使用 18-F-FDG 作为示踪剂对怀疑有心脏疾病的人进行双门控。
该方法在体内成像中被发现是可行的，并且在门控图像中放射性导管尖端的分辨率更高。在人体研究中，双门控被发现是可行的，并且易于临床常规使用。心外膜表面在头脚方向上的最大运动超过 20 毫米。心肌的形状在门之间明显不同，舒张图像中乳头肌变得更加清晰。
使用稳健的心脏-呼吸双门控的首次临床经验令人鼓舞。需要使用专门设计用于斑块成像的示踪剂在更大的临床人群中进行进一步测试。
