DePuey E Gordon
Icahn School of Medicine, Mt. Sinai St. Luke's and Mt. Sinai West Hospitals, New York, NY, USA.
J Nucl Cardiol. 2016 Aug;23(4):795-802. doi: 10.1007/s12350-016-0460-0. Epub 2016 Apr 12.
Although the new solid-state dedicated cardiac cameras provide excellent spatial and energy resolution and allow for markedly reduced SPECT acquisition times and/or injected radiopharmaceutical activity, they have some distinct disadvantages compared to traditional sodium iodide SPECT cameras. They are expensive. Attenuation correction is not available. Cardio-focused collimation, advantageous to increase depth-dependent resolution and myocardial count density, accentuates diaphragmatic attenuation and scatter from subdiaphragmatic structures. Although supplemental prone imaging is therefore routinely advised, many patients cannot tolerate it. Moreover, very large patients cannot be accommodated in the solid-state camera gantries. Since data are acquired simultaneously with an arc of solid-state detectors around the chest, no temporally dependent "rotating" projection images are obtained. Therefore, patient motion can be neither detected nor corrected. In contrast, traditional sodium iodide SPECT cameras provide rotating projection images to allow technologists and physicians to detect and correct patient motion and to accurately detect the position of soft tissue attenuators and to anticipate associated artifacts. Very large patients are easily accommodated. Low-dose x-ray attenuation correction is widely available. Also, relatively inexpensive low-count density software is provided by many vendors, allowing shorter SPECT acquisition times and reduced injected activity approaching that achievable with solid-state cameras.
尽管新型固态专用心脏相机具有出色的空间和能量分辨率,能够显著缩短单光子发射计算机断层扫描(SPECT)采集时间和/或减少注射的放射性药物活性,但与传统的碘化钠SPECT相机相比,它们存在一些明显的缺点。它们价格昂贵。无法进行衰减校正。心脏聚焦准直有利于提高深度依赖性分辨率和心肌计数密度,但会加剧膈肌衰减和来自膈下结构的散射。因此,尽管常规建议进行补充俯卧位成像,但许多患者无法耐受。此外,非常肥胖的患者无法进入固态相机的扫描架。由于数据是通过围绕胸部的固态探测器弧同时采集的,因此无法获得与时间相关的“旋转”投影图像。因此,既无法检测也无法校正患者的运动。相比之下,传统的碘化钠SPECT相机提供旋转投影图像,使技术人员和医生能够检测和校正患者的运动,准确检测软组织衰减器的位置,并预测相关伪影。非常肥胖的患者也能轻松容纳。低剂量X射线衰减校正广泛可用。此外,许多供应商提供相对便宜的低计数密度软件,允许缩短SPECT采集时间并减少注射活性,接近固态相机所能达到的水平。