Lee Benjamin C, Moody Jonathan B, Weinberg Richard L, Corbett James R, Ficaro Edward P, Murthy Venkatesh L
INVIA Medical Imaging Solutions, 3025 Boardwalk St., Suite 200, Ann Arbor, MI, USA.
Division of Cardiovascular Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA.
J Nucl Cardiol. 2017 Oct;24(5):1517-1529. doi: 10.1007/s12350-017-0899-7. Epub 2017 May 15.
Suboptimal temporal sampling of left ventricular (LV) blood pool and tissue time-activity curves (TACs) may introduce bias and increased variability in estimates of myocardial blood flow (MBF) and flow reserve (MFR) from dynamic PET myocardial perfusion images. We aimed to optimize temporal sampling for estimation of MBF and MFR.
Twenty-four normal volunteers and 32 patients underwent dynamic stress/rest rubidium-82 chloride (Rb) PET imaging. Fine temporal sampling was used to estimate the full width at half maximum (FWHM) of the LV blood pool TAC. Fourier analysis was used to determine the longest sampling interval, T , as a function of FWHM, which preserved the information content of the blood phase. Dynamic datasets were reconstructed with frame durations varying from 2 to 20 seconds over the first 2 minutes for the blood phase and 30 to 120 seconds for the tissue phase. The LV blood pool and tissue TACs were sampled using regions of interest (ROI) and fit to a compartment model for quantification of MBF and MFR. The effects of temporal sampling on MBF and MFR were evaluated using clinical data and simulations.
T increased linearly with input function FWHM (R = 0.93). Increasing the blood phase frame duration from 5 to 15 seconds resulted in MBF and MFR biases of 6-12% and increased variability of 14-24%. Frame durations <5 seconds had biases of less than 5% for both MBF and MFR values. Increasing the tissue phase frame durations from 30 to 120 seconds resulted in <5% biases.
A two-phase framing of dynamic Rb PET images with frame durations of 5 seconds (blood phase) and 120 seconds (tissue phase) optimally samples the blood pool TAC for modern 3D PET systems.
左心室血池和组织时间-活性曲线（TAC）的时间采样不理想，可能会在通过动态PET心肌灌注图像估计心肌血流量（MBF）和血流储备（MFR）时引入偏差并增加变异性。我们旨在优化用于估计MBF和MFR的时间采样。
24名正常志愿者和32名患者接受了动态负荷/静息氯化铷（Rb）PET成像。采用精细时间采样来估计左心室血池TAC的半高宽（FWHM）。使用傅里叶分析来确定最长采样间隔T，它是FWHM的函数，可保留血池期的信息内容。动态数据集重建时，血池期在前2分钟内的帧持续时间从2秒变化到20秒，组织期的帧持续时间从30秒变化到120秒。使用感兴趣区（ROI）对左心室血池和组织TAC进行采样，并拟合到房室模型以量化MBF和MFR。使用临床数据和模拟评估时间采样对MBF和MFR的影响。
T随输入函数FWHM呈线性增加（R = 0.93）。将血池期帧持续时间从5秒增加到15秒会导致MBF和MFR偏差为6 - 12%，变异性增加14 - 24%。帧持续时间<5秒时，MBF和MFR值的偏差均小于5%。将组织期帧持续时间从30秒增加到120秒导致偏差<5%。
对于现代3D PET系统，动态Rb PET图像采用5秒（血池期）和120秒（组织期）的两阶段成帧可对血池TAC进行最佳采样。
