Enhanced imaging with multi-pinhole single-photon emission computed tomography

多针孔单光子发射计算机断层扫描增强成像

• 批准号: RGPIN-2022-05080
• 负责人: Wells, Roger
• 金额: $ 3.64万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=757094
• 关键词: Enhanced; imaging; multi; pinhole; single

Single-photon emission computed tomography (SPECT) is a commonly used imaging modality. Cardiac-specific multi-pinhole cameras with solid-state detectors are now in use that have improved sensitivity and improved spatial, energy and temporal resolution allowing dynamic 3D imaging. However, pinhole collimators produce variable resolution, magnification, and sensitivity across the camera's field of view. These factors lead to image artifacts that may cause inaccurate interpretation and misdiagnosis. They also make it more difficult to correct for image degrading factors such as attenuation, scatter, patient motion, which is essential for accurate qualitative and quantitative evaluation. Multi-pinhole SPECT is currently interpreted without any of these corrections, reducing image quality and test accuracy. The long-term goal of my program is to improve the quantitative accuracy and precision of imaging with multi-pinhole cardiac SPECT(/CT). My short-term objectives are: Aim 1) Develop novel methods for co-registration of transmission and emission datasets using data consistency conditions for the purpose of attenuation correction. Aim 2) Use accurate scatter modeling to integrate the signal from lower energy windows and thereby increase the signal-to-noise ratio (SNR) of pinhole SPECT images. Aim 3) Develop novel methods of motion correction (MC) for dynamic SPECT imaging to improve the accuracy, precision and repeatability of MBF measurements. The general approach of my laboratory is to develop and validate advanced image reconstruction and analysis methods using analytic or Monte Carlo computer simulations, followed by evaluation using physical phantom experiments and datasets from real patient studies. Attenuation, scatter and motion depend strongly on body shape and size. Thus in selecting data sets for evaluation, we use a mixture of scans to ensure a diverse sampling of sexes, body shapes and sizes. Extra-cardiac signals violate the assumptions of the data consistency conditions, so Aim 1 will use cardiac contractile motion to separate the heart from static background signals. Aims 2 and 3 will use machine-learning (ML) to estimate scatter over a range of energies and to register images and estimate motion from dynamic imaging. The proposed work will exploit the energy-dimension and time-dimension of the acquired SPECT data to enhance and expand the information available for medical imaging. My lab provides a rich training environment for undergraduate and graduate student education. As part of the CAMPEP accredited Ottawa-Carleton joint program in medical physics, students interact with others engaged in a wide variety of medical physics projects. As part of the University of Ottawa Heart Institute, students are also exposed to the medical motivation that drives much of this field of research as well as to the broad multi-disciplinary nature of this field with exposure to research from microbiology to radiochemistry and tissue engineering.

单光子发射计算机断层扫描（SPECT）是一种常用的成像方式。现在正在使用具有固态检测器的心脏专用多针孔相机，其具有改进的灵敏度和改进的空间、能量和时间分辨率，允许动态3D成像。然而，针孔准直器在相机的视场内产生可变的分辨率、放大率和灵敏度。这些因素导致图像伪影，可能导致不准确的解释和误诊。它们还使得更难以校正图像退化因素，例如衰减、散射、患者运动，这对于准确的定性和定量评估至关重要。多针孔SPECT目前解释没有任何这些校正，降低图像质量和测试精度。我的项目的长期目标是提高多针孔心脏SPECT（/CT）成像的定量准确性和精确度。我的短期目标是：目标1）开发新的方法，使用数据一致性条件进行传输和发射数据集的配准，以进行衰减校正。目的2）利用精确的散射模型对低能量窗的信号进行积分，从而提高针孔SPECT图像的信噪比。目的3）发展新的运动校正（MC）方法，以提高SPECT动态显像MBF测量的准确性、精密度和可重复性。我实验室的一般方法是使用分析或蒙特卡罗计算机模拟开发和验证先进的图像重建和分析方法，然后使用物理体模实验和来自真实的患者研究的数据集进行评估。衰减、散射和运动强烈地依赖于身体的形状和大小。因此，在选择数据集进行评估时，我们使用混合扫描，以确保性别，体型和尺寸的多样性。心外信号违反数据一致性条件的假设，因此Aim 1将使用心脏收缩运动将心脏与静态背景信号分离。目标2和3将使用机器学习（ML）来估计能量范围内的散射，并配准图像和估计动态成像的运动。所提出的工作将利用所获得的SPECT数据的能量维度和时间维度来增强和扩展可用于医学成像的信息。我的实验室为本科生和研究生教育提供了丰富的培训环境。作为CAMPEP认可的渥太华-卡尔顿医学物理联合项目的一部分，学生与其他从事各种医学物理项目的人互动。作为渥太华大学心脏研究所的一部分，学生们还接触到推动这一研究领域的医学动机，以及这一领域广泛的多学科性质，接触到从微生物学到放射化学和组织工程的研究。