患者移动对双探头心肌灌注断层采集的影响

Effect of patient motion on dual head tomographic myocardial perfusion

目的探讨双探头ＳＰＥＣＴ仪心肌灌注断层采集中患者身体移动产生的影响。方法２只探头置成９０°夹角，双探头采集９０°，单探头采集１８０°（关闭１只探头）。心肌灌注断层采集中移动心肌模型模拟患者移动，Ｘ和Ｙ分别移动１个、２个和３个像素。采用移动探测软件对原始图像进行移动测试，图像重建后进行靶心图分析。结果在双探头采集中，Ｙ方向模型的１次移动相当于出现３次移动；Ｘ方向的１次移动同样会导致多次移动，但程度与探头平面和Ｘ轴的夹角有关。在Ｙ方向，单探头２个像素的移动、双探头１个像素的移动导致靶心图出现心尖计数下降。Ｘ方向移动的影响与探头平面和Ｘ轴的夹角有明显关系。在实验的２个移动位置中，３１５°位置１个像素的移动使单探头靶心图的心壁、双探头的心壁和心尖出现计数下降，单探头在２７０°位置的移动影响较小。结论双探头心肌灌注采集过程中患者移动的影响比用单探头时显著。

Objective To evaluate the effect of patient motion on dual head tomography and the difference between the effects on single and dual head tomography Methods By setting two heads in 90° orientation, a 90° tomographic myocardial perfusion imaging was performed on dual head and a 180° was performed on single head (the other one was closed) During imaging, a myocardial phantom was moved along the X and Y axial direction sequentially at one time, and covered 1 Pixel, 2 Pixels and 3 Pixels, respectively Raw images were analysed with a motion detection software and reconstructed images were analysed with polar map Results ①Motion detection: in dual head imaging, three motions were detected on one motion along Y direction and multi motions were also detected on one motion along X direction but the motion extent was related to the angle θ between the detector plane and the X direction ②Polar map analysis: in Y direction, 2 pixel motion in single head imaging and 1 pixel motion in dual head imaging could cause count decrease in apex In X direction, the effect extent related to θ One pixel motion at 315° could result in count decrease in wall in single head imaging and in apex and wall in dual head imaging But at 270° motion the effect was slight on single head imaging Conclusions The effect of patient motion on dual head tomographic myocardial perfusion is more striking than that on single head imaging