IEEE Trans Biomed Eng. 2024 Sep;71(9):2749-2758. doi: 10.1109/TBME.2024.3392333. Epub 2024 Aug 21.
Investigate the capacity of MRI to evaluate efficacy of radiofrequency (RF) ablations delivered to MRI-defined arrhythmogenic substrates.
Baseline MRI was performed at 3 T including 3D LGE in a swine model of chronic myocardial infarct (N = 8). MRI-derived maps of scar and heterogeneous tissue channels (HTCs) were generated using ADAS 3D. Animals underwent electroanatomic mapping and ablation of the left ventricle in CARTO3, guided by MRI-derived scar maps. Post-ablation MRI (in vivo at 3 T in 5/8 animals; ex vivo at 1.5 T in 3/8) included 3D native T1-weighted IR-SPGR (TI = 700-800 ms) to visualize RF lesions. T1-derived RF lesions were compared against excised tissue. The locations of T1-derived RF lesions were compared against CARTO ablation tags, and segment-wise sensitivity and specificity of lesion detection were calculated within the AHA 17-segment model.
RF lesions were clearly visualized in HTCs, scar, and myocardium. Ablation patterns delivered in CARTO matched T1-derived RF lesion patterns with high sensitivity (88.9%) and specificity (94.7%), and were closely matched in registered MR-EP data sets, with a displacement of 5.4 ±3.8 mm (N = 152 ablation tags).
Integrating MRI into ablative procedures for RF lesion assessment is feasible. Patterns of RF lesions created using a standard 3D EAM system are accurately reflected by MRI visualization in healthy myocardium, scar, and HTCs comprising the MRI-defined arrhythmia substrate.
MRI visualization of RF lesions can provide near-immediate ( 24 h) assessment of ablation, potentially indicating whether critical MRI-defined ventricular tachycardia substrates have been adequately ablated.
探究 MRI 评估射频（RF）消融治疗 MRI 定义的心律失常基质效果的能力。
在慢性心肌梗死猪模型中（N=8）进行 3T 基线 MRI 检查，包括 3D LGE。使用 ADAS 3D 生成疤痕和异质组织通道（HTCs）的 MRI 衍生图谱。动物在 CARTO3 中进行电解剖映射和左心室消融，由 MRI 衍生的疤痕图谱指导。消融后 MRI（5/8 只动物在体内 3T，3/8 只动物在体外 1.5T）包括 3D 原生 T1 加权 IR-SPGR（TI=700-800ms）以显示 RF 损伤。将 T1 衍生的 RF 损伤与切除组织进行比较。将 T1 衍生的 RF 损伤位置与 CARTO 消融标记进行比较，并在 AHA 17 节段模型内计算病变检测的分段敏感性和特异性。
RF 损伤在 HTCs、疤痕和心肌中清晰可见。在 CARTO 中传递的消融模式与 T1 衍生的 RF 损伤模式具有高度的敏感性（88.9%）和特异性（94.7%），并且在注册的 MR-EP 数据集之间非常匹配，具有 5.4±3.8mm 的位移（N=152 个消融标记）。
将 MRI 整合到 RF 损伤评估的消融程序中是可行的。使用标准的 3D EAM 系统创建的 RF 损伤模式在健康心肌、疤痕和构成 MRI 定义的心律失常基质的 HTCs 中，通过 MRI 可视化得到准确反映。
RF 损伤的 MRI 可视化可以提供近乎即时（24 小时）的消融评估，可能表明是否已充分消融关键的 MRI 定义的室性心动过速基质。
