Kliner Dustin, Wang Li, Winger Daniel, Follansbee William P, Soman Prem
Division of Cardiology, University of Pittsburgh Medical Center, A-429, Scaife Hall, 200 Lothrop Street, Pittsburgh, PA, 15238, USA.
Clinical and Translational Science Institute (CTSI), University of Pittsburgh, Pittsburgh, PA, USA.
J Nucl Cardiol. 2015 Dec;22(6):1237-43. doi: 10.1007/s12350-015-0071-1. Epub 2015 Feb 20.
Gated single-photon emission computed tomography (SPECT) is widely used for myocardial perfusion imaging and provides an automated assessment of left ventricular ejection fraction (LVEF). We prospectively tested the repeatability of serial SPECT-derived LVEF. This information is essential in order to inform the interpretation of a change in LV function on serial testing.
Consenting patients (n = 50) from among those referred for clinically indicated gated myocardial perfusion SPECT (MPs) were recruited. Following the clinical rest-stress study, patients were repositioned on the camera table for a second acquisition using identical parameters. Patient positioning, image acquisition and processing for the second scan were independently performed by a technologist blinded to the clinical scan. Quantitative LVEF was generated by Quantitative Gated SPECT and recorded as EF1 and EF2, respectively. Repeatability of serial results was assessed using the Bland-Altman method. The limits of repeatability and repeatability coefficients were generated to determine the maximum variation in LVEF that can be expected to result from test variability. Repeatability was tested across a broad range of LV systolic function and myocardial perfusion.
The mean difference between EF1 and EF2 was 1.6% (EF units), with 95% limits of repeatability of +9.1% to -6.0% (repeatability coefficient 7.5%). Correlation between serial EF measurements was excellent (r = 0.9809). Similar results were obtained in subgroups based on normal or abnormal EF and myocardial perfusion. The largest repeatability coefficient of 8.1% was seen in patients with abnormal LV systolic function.
When test protocol and acquisition parameters are kept constant, a difference of >8% EF units on serial MPs is indicative of a true change 95% of the time.
门控单光子发射计算机断层扫描（SPECT）广泛用于心肌灌注成像，并能自动评估左心室射血分数（LVEF）。我们前瞻性地测试了连续SPECT得出的LVEF的可重复性。这些信息对于解读连续检测时左心室功能的变化至关重要。
招募了因临床需要而行门控心肌灌注SPECT（MPS）检查的患者中的50名同意参与研究的患者。在进行临床静息-负荷试验后，患者重新在检查台上定位，使用相同参数进行第二次采集。第二次扫描的患者定位、图像采集和处理由对临床扫描结果不知情的技术人员独立完成。通过定量门控SPECT生成定量LVEF，并分别记录为EF1和EF2。使用Bland-Altman方法评估连续结果的可重复性。生成可重复性限度和可重复性系数，以确定因检测变异性导致的LVEF的最大变化。在广泛的左心室收缩功能和心肌灌注范围内测试可重复性。
EF1和EF2之间的平均差异为1.6%（EF单位），可重复性的95%限度为+9.1%至-6.0%（可重复性系数7.5%）。连续EF测量之间的相关性极佳（r = 0.9809）。在基于正常或异常EF及心肌灌注的亚组中也获得了类似结果。左心室收缩功能异常的患者中观察到的最大可重复性系数为8.1%。
当检测方案和采集参数保持恒定时，连续MPS上EF单位差异>8%表明95%的情况下存在真正的变化。
