The reproducibility of late gadolinium enhancement cardiovascular magnetic resonance imaging of post-ablation atrial scar: a cross-over study
The reproducibility of late gadolinium enhancement cardiovascular magnetic resonance imaging of post-ablation atrial scar: a cross-over study
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DOI：
10.1186/s12968-018-0438-y
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发表时间：
2018-03-19
影响因子：
6.4
通讯作者：
Razavi, Reza
中科院分区：
文献类型：
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作者：
Chubb, Henry;Karim, Rashed;Razavi, Reza
背景资料：心血管磁共振（CMR）成像已用于可视化消融后心房瘢痕（PAAS），通常采用三维（3D）晚期钆增强（LGE）技术。然而，PAAS成像的再现性尚未确定。这项交叉研究是第一项研究该技术的可重复性的研究，这对未来的研究设计和临床实施至关重要。方法：四十名接受首次房颤（AF）消融的受试者对PAAS进行了详细的CMR评估。基线消融前扫描后，在消融后3个月进行两次扫描（间隔48小时）。每次扫描均包括钆基造影剂（GBCA）给药后10、20和30 min的3D LGE采集。在消融后第二次扫描时，将受试者分配至相同的成像参数（“Repro”，n = 10）、3 T扫描仪（“3 T”，n = 10）、半层厚度（“半层”，n = 10）或半GBCA剂量（“半gad”，n = 10）。将PAAS与基线瘢痕进行比较，然后评估阈值瘢痕的两个测量值（PAAS占据的左心房（LA）%（LA PAAS %）和肺静脉栓塞（PVE））的再现性，然后评估非阈值瘢痕的四个测量值（PAAS逐点评估，四种标准化方法）。根据手术结果（AF复发）评价PAAS的保留措施。结果：共采集了271次3D采集（最多280次，96.7%）。在20和30 min时，扫描间重现性良好至极好（20 min和30 min时的变异系数：“Repro”组的% LA PAAS分别为0.41和0.20; PVE分别为0.13和0.04）。成像参数的变化，特别是GBCA剂量降低，扫描间重现性降低，但大多数测量结果仍为良好至极好（30 min时% LA PAAS的ICC为0.454-0.825，PVE为0.618-0.809）。对于非阈值瘢痕，使用血池z评分标准化技术观察到最高的再现性：扫描间ICC 0.759（绝对一致性，“Repro”组）。PAAS指数与AF复发无显著相关性。结论：PAAS影像学检查具有重复性。应在GBCA注射后至少20分钟进行成像，并应考虑血池z评分用于信号强度的标准化。这些发现的临床意义仍有待建立在没有一个简单的相关性与心律失常的结果。
Background: Cardiovascular magnetic resonance (CMR) imaging has been used to visualise post-ablation atrial scar (PAAS), generally employing a three-dimensional (3D) late gadolinium enhancement (LGE) technique. However the reproducibility of PAAS imaging has not been determined. This cross-over study is the first to investigate the reproducibility of the technique, crucial for both future research design and clinical implementation.Methods: Forty subjects undergoing first time ablation for atrial fibrillation (AF) had detailed CMR assessment of PAAS. Following baseline pre-ablation scan, two scans (separated by 48 h) were performed at three months post-ablation. Each scan session included 3D LGE acquisition at 10, 20 and 30 min post administration of gadolinium-based contrast agent (GBCA). Subjects were allocated at second scan post-ablation to identical imaging parameters ('Repro', n = 10), 3 T scanner ('3 T', n = 10), half-slice thickness ('Half-slice', n = 10) or half GBCA dose ('Half-gad', n = 10). PAAS was compared to baseline scar and then reproducibility was assessed for two measures of thresholded scar (% left atrial (LA) occupied by PAAS (% LA PAAS) and Pulmonary Vein Encirclement (PVE)), and then four measures of non-thresholded scar (point-by-point assessment of PAAS, four normalisation methods). Thresholded measures of PAAS were evaluated against procedural outcome (AF recurrence).Results: A total of 271 3D acquisitions (out of maximum 280, 96.7%) were acquired. At 20 and 30 min, inter-scan reproducibility was good to excellent (coefficient of variation at 20 min and 30 min: % LA PAAS 0.41 and 0.20; PVE 0.13 and 0.04 respectively for 'Repro' group). Changes in imaging parameters, especially reduced GBCA dose, reduced inter-scan reproducibility, but for most measures remained good to excellent (ICC for % LA PAAS 0.454-0.825, PVE 0.618-0.809 at 30 min). For non-thresholded scar, highest reproducibility was observed using blood pool z-score normalisation technique: inter-scan ICC 0.759 (absolute agreement, 'Repro' group). There was no significant relationship between indices of PAAS and AF recurrence.Conclusion: PAAS imaging is a reproducible finding. Imaging should be performed at least 20 min post-GBCA injection, and a blood pool z-score should be considered for normalisation of signal intensities. The clinical implications of these findings remain to be established in the absence of a simple correlation with arrhythmia outcome.