Novel acquisition strategies for cardiovascular functional and molecular imaging

描述（由申请人提供）：心肌灌注成像与单光子发射断层扫描（SPECT）仍然是诊断和评估冠状动脉疾病（CAD）至关重要。区分正常心肌区域与缺血或梗死心肌区域的能力对于患者管理和确定患者预后至关重要。目前，心脏SPECT成像至少需要两次成像才能获得应激和休息条件下的灌注图像，每次成像持续15 - 20分钟。此外，第二代SPECT/CT成像仪现在可以将心肌灌注成像与计算机断层扫描的心脏解剖评估相结合；因此，SPECT/CT有潜力提供一个完整的灌注研究，结合CT评估心脏力学（射血分数，卒中容量，心肌增厚），冠状动脉通畅，冠状动脉钙化状态在一个单一的双模成像会议。然而，SPECT/CT联合心肌方案将花费长达60分钟的时间，几乎所有的时间都需要SPECT，并且会使这种昂贵的设备在临床中的利用率低下，因此可能成本过高。因此，在本研究中，研究人员提出开发多针孔SPECT成像技术，其目标是在保持或提高空间分辨率的同时，将检测效率提高20倍。此外，研究人员假设，由于多针孔方法的信噪比提高，该方法将允许同时进行双同位素成像，这进一步减少了研究时间。本研究的具体目标如下：(1)开发并构建一套适合临床心肌灌注成像的20针孔准直成像系统。(2)我们将进行实验，以确定多针孔准直器的最小视图数，以最小化心脏的角度采样伪影。我们将通过SPECT获得拟人化幻体的心肌灌注图像，这些图像与CT的高分辨率解剖图像相关，我们将使用先验结构信息来校正SPECT图像的衰减。(3)我们将评估多针孔准直器同时双同位素心肌灌注成像。在本研究中，我们将证明，与使用平行孔准直器获得的投影数据相比，使用多针孔准直器获得的201TI/99mTc同时成像的串扰校正可以显着提高。总的来说，多针孔SPECT/CT的成功开发有望大大提高心肌状态和心功能综合评估的可行性和成本效益，从而促进冠状动脉疾病患者的改善护理和管理。

DESCRIPTION (provided by applicant): Myocardial perfusion imaging with single photon emission tomography (SPECT) remains critically important for diagnosing and assessing coronary artery disease (CAD). The ability to differentiate normal myocardial regions from those that are ischemic or infarcted is essential for patient management and for determining patient prognosis. Currently, cardiac SPECT imaging requires at least two imaging sessions to obtain perfusion images under stress and under rest conditions, with each imaging session lasting 15 to 20 min. Furthermore, second generation SPECT/CT imagers now are available that can combine myocardial perfusion imaging with anatomical assessment of the heart with computed tomography; SPECT/CT therefore has the potential to provide a complete perfusion study combined with CT assessment of cardiac mechanics (ejection fraction, stroke volume, myocardial thickening), coronary patency, and status of coronary calcification in a single dual-modality imaging session. However, a combined SPECT/CT myocardial protocol would take up to 60 min, with virtually all of this time needed for SPECT, and would make poor utilization of this expen- sive equipment in the clinic and therefore may be cost prohibitive. Therefore, in this study the investigators propose to develop multipinhole SPECT imaging techniques with the goal of improving detection efficiency by 20-fold while maintaining or improving the spatial resolution in comparison to current SPECT imaging techniques. In addition, the investigators hypothesize that this method will allow simultaneous dual isotope imaging due to an improved signal to noise ratio of the multipinhole approach, which represents a further reduction in study time. The study encompasses the following specific aims: (1) We will develop and build a 20-pinhole collimator imaging system optimized for clinical myocardial perfusion imaging. (2) We will perform experiments to determine the minimal number of views of a multipinhole collimator sufficient to minimize angular sampling artifacts of the heart. We will obtain myocardial perfusion images of an anthropomorphic phantom with SPECT that are correlated with high-resolution anatomical images with CT and we will implement methods of correcting the SPECT image for attenuation using a priori structural information. (3) We will evaluate simultaneous dual-isotope imaging of myocardial perfusion with a multipinhole collimator. In this study, we will demonstrate that cross-talk correction of simultaneous 201TI/99mTc imaging can be improved significantly in the projection data acquired with a multipinhole collimator versus that obtained with a parallel hole collimator. Overall, successful development of multipinhole SPECT/CT promises to substantially increase the feasibility and cost-effectiveness of a comprehensive assessment of myocardial status and cardiac function in a way that will promote improved care and management of patients with coronary artery disease. '