Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, 22 South Greene St., Baltimore, MD, 21201, USA.
Siemens Healthineers, Knoxville, TN, USA.
J Nucl Cardiol. 2018 Oct;25(5):1521-1545. doi: 10.1007/s12350-018-1311-y. Epub 2018 Jun 15.
The effect of time-of-flight (TOF) and point spread function (PSF) modeling in image reconstruction has not been well studied for cardiac PET. This study assesses their separate and combined influence on Rb myocardial perfusion imaging in obese patients.
Thirty-six obese patients underwent rest-stress Rb cardiac PET. Images were reconstructed with and without TOF and PSF modeling. Perfusion was quantitatively compared using the AHA 17-segment model for patients grouped by BMI, cross-sectional body area in the scanner field of view, gender, and left ventricular myocardial volume. Summed rest scores (SRS), summed stress scores (SSS), and summed difference scores (SDS) were compared.
TOF improved polar map visual uniformity and increased septal wall perfusion by up to 10%. This increase was greater for larger patients, more evident for patients grouped by cross-sectional area than by BMI, and more prominent for females. PSF modeling increased perfusion by about 1.5% in all cardiac segments. TOF modeling generally decreased SRS and SSS with significant decreases between 2.4 and 3.0 (P < .05), which could affect risk stratification; SDS remained about the same. With PSF modeling, SRS, SSS, and SDS were largely unchanged.
TOF and PSF modeling affect regional and global perfusion, SRS, and SSS. Clinicians should consider these effects and gender-dependent differences when interpreting Rb perfusion studies.
在心脏 PET 中，尚未对飞行时间（TOF）和点扩散函数（PSF）建模在图像重建中的影响进行很好的研究。本研究评估了它们对肥胖患者铷心肌灌注成像的单独和联合影响。
36 名肥胖患者接受静息-应激铷心脏 PET 检查。图像分别进行了 TOF 和 PSF 建模和未建模的重建。根据 BMI、扫描视野中的横截面积、性别和左心室心肌体积对患者进行分组，使用 AHA 17 节段模型对灌注进行定量比较。比较了总和静息评分（SRS）、总和应激评分（SSS）和总和差评分（SDS）。
TOF 改善了极地图的视觉均匀性，并将间隔壁灌注提高了多达 10%。对于较大的患者，这种增加更为明显，按横截面积分组的患者比按 BMI 分组的患者更为明显，女性更为明显。PSF 建模使所有心脏节段的灌注增加了约 1.5%。TOF 建模通常会降低 SRS 和 SSS，差异在 2.4 到 3.0 之间具有统计学意义（P <.05），这可能会影响风险分层；SDS 基本保持不变。进行 PSF 建模后，SRS、SSS 和 SDS 基本保持不变。
TOF 和 PSF 建模会影响局部和整体灌注、SRS 和 SSS。临床医生在解释铷灌注研究时应考虑这些影响和性别依赖性差异。
