Reproducibility of in-vivo diffusion tensor cardiovascular magnetic resonance in hypertrophic cardiomyopathy.
Reproducibility of in-vivo diffusion tensor cardiovascular magnetic resonance in hypertrophic cardiomyopathy.
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DOI：
10.1186/1532-429x-14-86
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发表时间：
2012-12-24
期刊：
影响因子：
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通讯作者：
Pennell DJ
中科院分区：
文献类型：
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作者：
McGill LA;Ismail TF;Nielles-Vallespin S;Ferreira P;Scott AD;Roughton M;Kilner PJ;Ho SY;McCarthy KP;Gatehouse PD;de Silva R;Speier P;Feiweier T;Mekkaoui C;Sosnovik DE;Prasad SK;Firmin DN;Pennell DJ
心肌紊乱是肥厚型心肌病（HCM）的一个重要组织学特征，已被研究死后，但其在体内的患病率和程度是未知的。心脏弥散张量成像（cDTI）提供了关于平均体素内心肌细胞方向和潜在心肌紊乱的信息。最近的技术进步改善了体内cDTI，本研究的目的是评估HCM患者体内定量cDTI的研究间重现性。一个刺激回波单激发EPI序列与区域激发和并行成像。10例HCM患者分别在2个不同的日期进行扫描。对于每次扫描，在收缩末期用cDTI采集3个短轴心室中段切片。使用内部开发的cDTI后处理平台创建分数各向异性（FA）、平均扩散率（MD）和螺旋角（HA）图。总体FA的平均值± SD为0.613 ± 0.044，MD为0.750 ± 0.154 × 10-3 mm 2/s，HA为心外膜−34.3 ± 7.6°、系膜3.5 ± 6.9°和心内膜38.9 ± 8.1°。初始和重复研究的比较显示FA（SD = ± 0.045，变异系数（CoV）= 7.2%）、MD（SD = ± 0.135 × 10-3 mm 2/s，CoV = 18.6%）和HA（心外膜SD = ± 4.8°;中膜SD = ± 3.4°;内膜SD = ± 2.9°）的总体研究间重现性。FA的重现性上级MD（p = 0.003）。间隔的总体MD显著高于参考侧壁（0.784 ± 0.188 vs 0.750 ± 0.154 x10-3 mm 2/s，p < 0.001）。在所有3个透壁层中，间隔HA显著低于参考侧壁（从−8.3°到−10.4°，所有p < 0.001）。据我们所知，这是第一项评估DTI在人体HCM心脏体内研究间重现性的研究，也是迄今为止HCM中最大的cDTI研究。我们的结果显示FA、MD和HA具有良好的重现性，这表明当前技术产生了具有潜在临床价值的稳健的体内测量。对中隔区域差异的解释需要进一步研究。
Myocardial disarray is an important histological feature of hypertrophic cardiomyopathy (HCM) which has been studied post-mortem, but its in-vivo prevalence and extent is unknown. Cardiac Diffusion Tensor Imaging (cDTI) provides information on mean intravoxel myocyte orientation and potentially myocardial disarray. Recent technical advances have improved in-vivo cDTI, and the aim of this study was to assess the interstudy reproducibility of quantitative in-vivo cDTI in patients with HCM. A stimulated-echo single-shot-EPI sequence with zonal excitation and parallel imaging was implemented. Ten patients with HCM were each scanned on 2 different days. For each scan 3 short axis mid-ventricular slices were acquired with cDTI at end systole. Fractional anisotropy (FA), mean diffusivity (MD), and helix angle (HA) maps were created using a cDTI post-processing platform developed in-house. The mean ± SD global FA was 0.613 ± 0.044, MD was 0.750 ± 0.154 × 10-3 mm2/s and HA was epicardium −34.3 ± 7.6°, mesocardium 3.5 ± 6.9° and endocardium 38.9 ± 8.1°. Comparison of initial and repeat studies showed global interstudy reproducibility for FA (SD = ± 0.045, Coefficient of Variation (CoV) = 7.2%), MD (SD = ± 0.135 × 10-3 mm2/s, CoV = 18.6%) and HA (epicardium SD = ± 4.8°; mesocardium SD = ± 3.4°; endocardium SD = ± 2.9°). Reproducibility of FA was superior to MD (p = 0.003). Global MD was significantly higher in the septum than the reference lateral wall (0.784 ± 0.188 vs 0.750 ± 0.154 x10-3 mm2/s, p < 0.001). Septal HA was significantly lower than the reference lateral wall in all 3 transmural layers (from −8.3° to −10.4°, all p < 0.001). To the best of our knowledge, this is the first study to assess the interstudy reproducibility of DTI in the human HCM heart in-vivo and the largest cDTI study in HCM to date. Our results show good reproducibility of FA, MD and HA which indicates that current technology yields robust in-vivo measurements that have potential clinical value. The interpretation of regional differences in the septum requires further investigation.