Clinical Physiology, Department of Clinical Sciences Lund, Skåne University Hospital, Lund University, Lund, Sweden.
Department of Clinical Physiology, Karolinska University Hospital, and Karolinska Institutet, Stockholm, Sweden.
J Cardiovasc Magn Reson. 2021 Oct 28;23(1):123. doi: 10.1186/s12968-021-00809-1.
Increased pulmonary blood volume (PBV) is a measure of congestion and is associated with an increased risk of cardiovascular events. PBV can be quantified using cardiovascular magnetic resonance (CMR) imaging as the product of cardiac output and pulmonary transit time (PTT), the latter measured from the contrast time-intensity curves in the right and left side of the heart from first-pass perfusion (FPP). Several methods of estimating PTT exist, including pulmonary transit beats (PTB), peak-to-peak, and center of gravity (CoG). The aim of this study was to determine the accuracy and precision for these methods of quantifying the PBV, taking the left atrium volume (LAV) into consideration.
Fifty-eight participants (64 ± 11 years, 24 women) underwent 1.5 T CMR. PTT was quantified from (1) a basal left ventricular short-axis image (FPP), and (2) the reference method with a separate contrast administration using an image intersecting the pulmonary artery (PA) and the LA (CoG(PA-LA)).
Compared to the reference, PBV for (a) PTB(FPP) was 14 ± 17% larger, (b) peak-peak(FPP) was 17 ± 16% larger, and (c) CoG(FPP) was 18 ± 10% larger. Subtraction of the LAV (available for n = 50) decreased overall differences to - 1 ± 19%, 2 ± 18%, and 3 ± 12% for PTB(FPP), peak-peak(FPP), and CoG(FPP), respectively. Lowest interobserver variability was seen for CoG(FPP) (- 2 ± 7%).
CoG(PA-LA) and FPP methods measured the same PBV only when adjusting for the LAV, since FPP inherently quantifies a volume consisting of PBV + LAV. CoG(FPP) had the best precision and lowest interobserver variability among the FPP methods of measuring PBV.
肺血容量（PBV）增加是充血的一种衡量标准，与心血管事件风险增加相关。PBV 可以使用心血管磁共振（CMR）成像来量化，作为心输出量和肺通过时间（PTT）的乘积，后者是从右心和左心的首过灌注（FPP）对比时间-强度曲线测量得出的。存在几种估计 PTT 的方法，包括肺通过搏动（PTB）、峰峰和重心（CoG）。本研究的目的是确定这些量化 PBV 的方法的准确性和精密度，同时考虑左心房容积（LAV）。
58 名参与者（64±11 岁，24 名女性）接受了 1.5T CMR 检查。PTT 是从（1）基本的左心室短轴图像（FPP）和（2）使用穿过肺动脉（PA）和左心房（LA）的图像进行单独对比给药的参考方法（CoG（PA-LA））进行量化的。
与参考方法相比，（a）PTB（FPP）的 PBV 大 14±17%，（b）峰峰（FPP）的 PBV 大 17±16%，（c）CoG（FPP）的 PBV 大 18±10%。减去可用的左心房容积（n=50）后，总体差异分别减少至-1±19%、2±18%和 3±12%，用于 PTB（FPP）、峰峰（FPP）和 CoG（FPP）。CoG（PA-LA）的观察者间变异性最低（-2±7%）。
只有在调整 LAV 后，CoG（PA-LA）和 FPP 方法才能测量相同的 PBV，因为 FPP 本质上量化的是由 PBV+LAV 组成的体积。在测量 PBV 的 FPP 方法中，CoG（FPP）具有最佳的精度和最低的观察者间变异性。
