Division of Cardiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA.
J Nucl Med. 2012 Jun;53(6):894-901. doi: 10.2967/jnumed.111.094904. Epub 2012 May 10.
The integration of myocardial scar models in 3-dimensional (3D) mapping systems may provide a novel way of helping to guide ventricular tachycardia (VT) ablations. This study assessed the value of (201)Tl SPECT perfusion imaging to define ventricular myocardial scar areas and to characterize electrophysiology voltage-derived myocardial substrate categories of scar, border zone (BZ), and normal myocardium regions. Scar and BZ regions have been implicated in the genesis of ventricular arrhythmias.
Ten patients scheduled for VT ablation underwent (201)Tl SPECT before the ablation procedure. 3D left ventricular (LV) scar models were created from the SPECT images. These scar models were registered with the LV voltage maps and analyzed with a 17-segment cardiac model. Scar location and scar burden were compared between the SPECT scar models and voltage maps. In addition, (201)Tl SPECT uptake was quantified using a 68-segment cardiac model and compared among voltage-defined scar, BZ, and normal segments.
3D models of LV myocardium and scar were successfully created from (201)Tl SPECT images and integrated in a clinical mapping system. The surface registration error with the electrophysiology voltage map was 4.4 ± 1.0 mm. The 3D scar location from SPECT matched in 72% of the segments with the voltage map findings. All successful ablation sites were located within the SPECT-defined scar or within 1 cm of its border, with 73% of the successful ablation sites within 1 cm of the scar border. Voltage measurements in SPECT-defined scar and normal areas were 1.2 ± 1.7 and 3.4 ± 2.8 mV, respectively (P < 0.001). The fractional SPECT scar burden area (18.8% ± 5.2%) agreed better with the abnormal (scar plus BZ) voltage area (20.8% ± 15.7%) than with the scar voltage area (5.8% ± 5.8%). Mean normalized (201)Tl uptake was 55% ± 21% in the voltage-defined scar, 63% ± 20% in BZ, and 79% ± 17% in normal myocardial segments (P < 0.05 for scar or BZ vs. normal).
3D SPECT surface models of LV scar were accurately integrated into a clinical mapping system and predicted endocardial voltage-defined scar. These preliminary data support the possible use of widely available (201)Tl SPECT to facilitate substrate-guided VT ablations.
评估放射性核素 201 铊（201Tl）单光子发射计算机断层扫描（SPECT）灌注成像在定义心室心肌瘢痕区域和对瘢痕、边界区（BZ）和正常心肌区域的电生理电压衍生心肌底物分类中的价值。瘢痕和 BZ 区域与室性心律失常的发生有关。
10 例行室性心动过速（VT）消融的患者在消融前进行 201Tl SPECT。从 SPECT 图像中创建左心室（LV）瘢痕的 3D 模型。这些瘢痕模型与 LV 电压图进行了注册，并使用 17 节段心脏模型进行了分析。比较 SPECT 瘢痕模型和电压图之间的瘢痕位置和瘢痕负荷。此外，使用 68 节段心脏模型量化 201Tl SPECT 摄取量，并比较电压定义的瘢痕、BZ 和正常节段之间的摄取量。
成功地从 201Tl SPECT 图像中创建了 LV 心肌和瘢痕的 3D 模型，并将其整合到临床映射系统中。与电生理电压图的表面注册误差为 4.4 ± 1.0mm。SPECT 定位的 3D 瘢痕位置与电压图发现的匹配率为 72%。所有成功的消融部位均位于 SPECT 定义的瘢痕内或其边界 1cm 范围内，73%的成功消融部位位于瘢痕边界 1cm 范围内。SPECT 定义的瘢痕和正常区域的电压测量值分别为 1.2 ± 1.7mV 和 3.4 ± 2.8mV（P < 0.001）。分数 SPECT 瘢痕负荷面积（18.8% ± 5.2%）与异常（瘢痕加 BZ）电压面积（20.8% ± 15.7%）的一致性优于瘢痕电压面积（5.8% ± 5.8%）。电压定义的瘢痕中归一化（201）Tl 摄取率为 55% ± 21%，BZ 中为 63% ± 20%，正常心肌节段中为 79% ± 17%（瘢痕或 BZ 与正常相比，P < 0.05）。
LV 瘢痕的 3D SPECT 表面模型被准确地整合到临床映射系统中，并预测了心内膜电压定义的瘢痕。这些初步数据支持使用广泛可用的 201Tl SPECT 来促进底物引导的 VT 消融。
