Miller Christopher A, Naish Josephine H, Ainslie Mark P, Tonge Christine, Tout Deborah, Arumugam Parthiban, Banerji Anita, Egdell Robin M, Clark David, Weale Peter, Steadman Christopher D, McCann Gerry P, Ray Simon G, Parker Geoffrey J M, Schmitt Matthias
North West Heart Centre, University Hospital of South Manchester, Wythenshawe Hospital, Manchester, UK.
J Cardiovasc Magn Reson. 2014 Jan 24;16(1):11. doi: 10.1186/1532-429X-16-11.
Quantitative assessment of myocardial blood flow (MBF) from cardiovascular magnetic resonance (CMR) perfusion images appears to offer advantages over qualitative assessment. Currently however, clinical translation is lacking, at least in part due to considerable disparity in quantification methodology. The aim of this study was to evaluate the effect of common methodological differences in CMR voxel-wise measurement of MBF, using position emission tomography (PET) as external validation.
Eighteen subjects, including 9 with significant coronary artery disease (CAD) and 9 healthy volunteers prospectively underwent perfusion CMR. Comparison was made between MBF quantified using: 1. Calculated contrast agent concentration curves (to correct for signal saturation) versus raw signal intensity curves; 2. Mid-ventricular versus basal-ventricular short-axis arterial input function (AIF) extraction; 3. Three different deconvolution approaches; Fermi function parameterization, truncated singular value decomposition (TSVD) and first-order Tikhonov regularization with b-splines. CAD patients also prospectively underwent rubidium-82 PET (median interval 7 days).
MBF was significantly higher when calculated using signal intensity compared to contrast agent concentration curves, and when the AIF was extracted from mid- compared to basal-ventricular images. MBF did not differ significantly between Fermi and Tikhonov, or between Fermi and TVSD deconvolution methods although there was a small difference between TSVD and Tikhonov (0.06 mL/min/g). Agreement between all deconvolution methods was high. MBF derived using each CMR deconvolution method showed a significant linear relationship (p<0.001) with PET-derived MBF however each method underestimated MBF compared to PET (by 0.19 to 0.35 mL/min/g).
Variations in more complex methodological factors such as deconvolution method have no greater effect on estimated MBF than simple factors such as AIF location and observer variability. Standardization of the quantification process will aid comparison between studies and may help CMR MBF quantification enter clinical use.
心血管磁共振（CMR）灌注图像对心肌血流量（MBF）的定量评估似乎比定性评估更具优势。然而目前，临床应用尚缺乏，至少部分原因是量化方法存在显著差异。本研究的目的是使用正电子发射断层扫描（PET）作为外部验证，评估CMR体素水平测量MBF时常见方法差异的影响。
18名受试者，包括9名患有严重冠状动脉疾病（CAD）的患者和9名健康志愿者，前瞻性地接受了灌注CMR检查。比较了使用以下方法量化的MBF：1. 计算的造影剂浓度曲线（以校正信号饱和）与原始信号强度曲线；2. 心室中部与心室基部短轴动脉输入函数（AIF）提取；3. 三种不同的反卷积方法；费米函数参数化、截断奇异值分解（TSVD）和带b样条的一阶蒂霍诺夫正则化。CAD患者还前瞻性地接受了铷-82 PET检查（中位间隔7天）。
与使用造影剂浓度曲线计算相比，使用信号强度计算时MBF显著更高，并且从心室中部图像提取AIF时比从心室基部图像提取时MBF更高。费米和蒂霍诺夫方法之间，或费米和TVSD反卷积方法之间的MBF没有显著差异，尽管TSVD和蒂霍诺夫之间存在小差异（0.06 mL/分钟/克）。所有反卷积方法之间的一致性很高。然而，与PET相比，使用每种CMR反卷积方法得出的MBF均显示与PET得出的MBF有显著线性关系（p<0.001），但每种方法均低估了MBF（低估0.19至0.35 mL/分钟/克）。
诸如反卷积方法等更复杂方法因素的变化对估计的MBF的影响并不比诸如AIF位置和观察者变异性等简单因素更大。量化过程的标准化将有助于不同研究之间的比较，并可能有助于CMR的MBF定量进入临床应用。
