Do Jeffrey, Ruddy Terrence D, Wells R Glenn
Division of Cardiology, University of Ottawa Heart Institute, 40 Ruskin St, Ottawa, Canada.
J Nucl Cardiol. 2021 Dec;28(6):2518-2529. doi: 10.1007/s12350-020-02048-w. Epub 2020 Feb 5.
Measurement of myocardial blood flow (MBF) is feasible using SPECT imaging but the acquisition requires more time than usual. Our study assessed the impact of reducing acquisition times on the accuracy and repeatability of the uptake rate constant (K1).
Twenty-nine patients underwent two rest/stress studies with Tc-99m-tetrofosmin 18 ± 13 days apart, using a one-day rest/stress dynamic SPECT imaging protocol with a solid-state cardiac camera. A 5-minute static image was acquired prior to tracer injection for subtraction of residual activity, followed immediately by 11-minute of list-mode data collection. Static image acquisition times of 0.5, 1, and 3 minutes and dynamic imaging times of 5, 7, and 9 minutes were simulated by truncating list-mode data. Images were reconstructed with/without attenuation correction and with/without motion correction. Kinetic parameters were calculated using a 1-tissue-compartment model.
K1 increased with reduced dynamic but not static imaging time (P < 0.001). The increase in K1 for a 9-minute scan was small (4.7 ± 5.3%) compared with full-length studies. The repeatability of K1 did not change significantly (13 ± 12%, P > 0.17).
A shortened imaging protocol of 3-minute (rest) or 30-second (stress) static image acquisition and 9 minutes of dynamic image acquisition altered K1 by less than 5% compared to a previously validated 11-minute acquisition.
使用单光子发射计算机断层扫描（SPECT）成像测量心肌血流量（MBF）是可行的，但采集时间比平时更长。我们的研究评估了缩短采集时间对摄取速率常数（K1）准确性和可重复性的影响。
29例患者在间隔18±13天的时间内接受了两次静息/负荷研究，使用Tc-99m-替曲膦，采用一日静息/负荷动态SPECT成像方案及固态心脏相机。在注射示踪剂前采集5分钟静态图像以减去残留活性，随后立即进行11分钟的列表模式数据采集。通过截断列表模式数据模拟0.5分钟、1分钟和3分钟的静态图像采集时间以及5分钟、7分钟和9分钟的动态成像时间。图像在有/无衰减校正和有/无运动校正的情况下进行重建。使用单组织室模型计算动力学参数。
K1随动态成像时间缩短而增加，但不随静态成像时间缩短而增加（P<0.001）。与全长研究相比，9分钟扫描时K1的增加幅度较小（4.7±5.3%）。K1的可重复性没有显著变化（13±12%，P>0.17）。
与先前验证的11分钟采集相比，缩短的成像方案（3分钟（静息）或30秒（负荷）静态图像采集和9分钟动态图像采集）使K1的变化小于5%。
