肺静脉心电图和呼吸门控、钆增强磁共振血管造影的可行性研究及心率和节律对研究质量的影响。

Feasibility study of electrocardiographic and respiratory gated, gadolinium enhanced magnetic resonance angiography of pulmonary veins and the impact of heart rate and rhythm on study quality.

机构信息

Cardiovascular Imaging Program, Cardiovascular Division, Department of Medicine and Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.

出版信息

J Cardiovasc Magn Reson. 2014 Jun 19;16(1):43. doi: 10.1186/1532-429X-16-43.

BACKGROUND

We aimed to assess the feasibility of 3 dimensional (3D) respiratory and ECG gated, gadolinium enhanced magnetic resonance angiography (MRA) on a 3 Tesla (3 T) scanner for imaging pulmonary veins (PV) and left atrium (LA). The impact of heart rate (HR) and rhythm irregularity associated with atrial fibrillation (AF) on image and segmentation qualities were also assessed.

METHODS

101 consecutive patients underwent respiratory and ECG gated (ventricular end systolic window) MRA for pre AF ablation imaging. Image quality (assessed by PV delineation) was scored as 1 = not visualized, 2 = poor, 3 = good and 4 = excellent. Segmentation quality was scored on a similar 4 point scale. Signal to noise ratios (SNRs) were calculated for the LA, LA appendage (LAA), and PV. Contrast to noise ratios (CNRs) were calculated between myocardium and LA, LAA and PV, respectively. Associations between HR/rhythm and quality metrics were assessed.

RESULTS

35 of 101 (34.7%) patients were in AF at time of MRA. 100 (99%) patients had diagnostic studies, and 91 (90.1%) were of good or excellent quality. Overall, mean ± standard deviation (SD) image quality score was 3.40 ± 0.69. Inter observer agreement for image quality scores was substantial, (kappa = 0.68; 95% confidence interval (CI): 0.46, 0.90). Neither HR adjusting for rhythm [odds ratio (OR) = 1.03, 95% CI = 0.98,1.09; p = 0.22] nor rhythm adjusting for HR [OR = 1.25, 95% CI = 0.20, 7.69; p = 0.81] demonstrated association with image quality. Similarly, SNRs and CNRs were largely independent of HR after adjusting for rhythm. Segmentation quality scores were good or excellent for 77.3% of patients: mean ± SD score = 2.91 ± 0.63, and scores did not significantly differ by baseline rhythm (p = 0.78).

CONCLUSIONS

3D respiratory and ECG gated, gadolinium enhanced MRA of the PVs and LA on a 3 T system is feasible during ventricular end systole, achieving high image quality and high quality image segmentation when imported into electroanatomic mapping systems. Quality is independent of HR and heart rhythm for this free breathing, radiation free, alternative strategy to current MRA or CT based approaches, for pre AF ablation imaging of PVs and LA.

背景

我们旨在评估在 3 特斯拉（3T）扫描仪上进行三维（3D）呼吸和心电图门控、钆增强磁共振血管造影（MRA）以成像肺静脉（PV）和左心房（LA）的可行性。还评估了与心房颤动（AF）相关的心率（HR）和节律不规则对图像和分割质量的影响。

方法

101 例连续患者在 AF 消融前进行呼吸和心电图门控（心室收缩末期窗）MRA。通过 PV 描绘评估图像质量（评分 1=不可见，2=差，3=好，4=优）。分割质量也按类似的 4 分制评分。计算 LA、LA 附件（LAA）和 PV 的信噪比（SNR）。计算心肌与 LA、LAA 与 PV 之间的对比噪声比（CNR）。评估 HR/节律与质量指标之间的关系。

结果

101 例患者中有 35 例（34.7%）在 MRA 时处于 AF 中。100 例（99%）患者进行了诊断性研究，91 例（90.1%）质量良好或优秀。总体而言，平均±标准偏差（SD）图像质量评分 3.40±0.69。图像质量评分的观察者间一致性较高（kappa=0.68；95%置信区间（CI）：0.46，0.90）。既不调整 HR（比值比（OR）=1.03，95%CI=0.98，1.09；p=0.22），也不调整节律（OR=1.25，95%CI=0.20，7.69；p=0.81）来调整心率，均与图像质量无关联。同样，在调整节律后，SNR 和 CNR 在很大程度上与 HR 无关。77.3%的患者分割质量评分良好或优秀：平均±SD 评分 2.91±0.63，基线节律无显著差异（p=0.78）。

结论

在 3T 系统上进行 3D 呼吸和心电图门控、钆增强 PV 和 LA MRA 在心室收缩末期是可行的，当导入电生理映射系统时，可获得高质量的图像和高质量的图像分割。对于 AF 消融前的 PV 和 LA 成像，这种自由呼吸、无辐射的替代策略与当前的 MRA 或 CT 方法相比，质量独立于 HR 和心率。