Cardiovascular Imaging Research Center and Core Lab at Minneapolis Heart Institute Foundation, Minneapolis, MN, USA.
Allina Health Minneapolis Heart Institute at Abbott Northwestern Hospital, Minneapolis, MN, USA.
J Cardiovasc Comput Tomogr. 2023 May-Jun;17(3):222-225. doi: 10.1016/j.jcct.2023.02.007. Epub 2023 Mar 13.
Computed tomography angiography (CTA) assessment of myocardial extracellular volume fraction (CT-ECV) is feasible, although the protocols for imaging acquisition and post-processing methodology have varied. We aimed to identify a pragmatic protocol for CT-ECV assessment encompassing both imaging acquisition and post-processing methodologies to facilitate its clinical implementation.
We evaluated consecutive patients with severe aortic stenosis undergoing evaluation for transcatheter aortic valve replacement (TAVR). Pre-contrast and 3-min-delayed CTA were obtained in systole using either helical prospective-ECG-triggered (high-pitch) or axial sequential-ECG-gated acquisition, adding to standard TAVR CTA protocol. Using a dedicated software for co-registration of CTA datasets, three methodologies for ECV measurement were evaluated: (1) mid-septum region of interest (Septal ECV), (2) averaged-global ECV (Global ECV) encompassing 16-AHA segments, and (3) average of septal and lateral segments (Averaged ECVsep and Averaged ECVlat).
Among the 142 patients enrolled (median = 81 years, 44% females), 8 were excluded due to significant imaging artifacts precluding Global ECV assessment. High-pitch scan mode was performed in 68 patients (48%). Suboptimal image quality for Global ECV assessment was associated with high-pitch scan mode (odds ratio: OR = 2.26, p = 0.036), along with the presence of intracardiac leads (OR = 4.91, p = 0.002), and BMI≥35 kg/m (OR = 2.80, p = 0.026). Septal ECV [median = 29.4%] and Averaged ECVsep [29.0%] were similar (p = 0.108), while Averaged ECVlat [27.5%] was lower than Averaged ECVsep (p < 0.001), resulting in lower Global ECV [28.6%].
Myocardial CT-ECV assessment is feasible using a systolic sequential acquisition pre-contrast, and similar additional 3-min delayed scan. Septal ECV measurement provides similar values to Global ECV and is equally reproducible.
心肌细胞外容积分数（CT-ECV）的计算机断层血管造影（CTA）评估是可行的，尽管成像采集和后处理方法的协议有所不同。我们旨在确定一种实用的 CT-ECV 评估方案，包括成像采集和后处理方法，以促进其临床应用。
我们评估了连续接受经导管主动脉瓣置换术（TAVR）评估的严重主动脉瓣狭窄患者。在收缩期使用螺旋前瞻性心电图触发（高螺距）或轴向顺序心电图门控采集获得预对比和 3 分钟延迟 CTA，并添加到标准 TAVR CTA 方案中。使用专用软件对 CTA 数据集进行配准，评估了三种 ECV 测量方法：（1）中隔感兴趣区（Septal ECV），（2）包含 16 个 AHA 节段的平均全局 ECV（Global ECV），以及（3）中隔和外侧节段的平均值（Averaged ECVsep 和 Averaged ECVlat）。
在纳入的 142 例患者中（中位数为 81 岁，44%为女性），8 例因严重的成像伪影而排除在外，无法进行 Global ECV 评估。68 例患者（48%）进行了高螺距扫描模式。高螺距扫描模式与 Global ECV 评估的图像质量差相关（比值比：OR=2.26，p=0.036），同时伴有心内导联（OR=4.91，p=0.002）和 BMI≥35kg/m（OR=2.80，p=0.026）。中隔 ECV[中位数=29.4%]和 Averaged ECVsep[29.0%]相似（p=0.108），而 Averaged ECVlat[27.5%]低于 Averaged ECVsep（p<0.001），导致 Global ECV 较低[28.6%]。
使用对比前的收缩期顺序采集和类似的额外 3 分钟延迟扫描，可以进行心肌 CT-ECV 评估。中隔 ECV 测量提供了与 Global ECV 相似的值，且具有同等的可重复性。
