Absolute Quantitation of Cardiac 99mTc-Pyrophosphate Using Cadmium-Zinc-Telluride-Based SPECT/CT
Absolute Quantitation of Cardiac 99mTc-Pyrophosphate Using Cadmium-Zinc-Telluride-Based SPECT/CT
复制标题
DOI：
10.2967/jnumed.120.247312
复制
发表时间：
2021-05-01
影响因子：
9.3
通讯作者：
Di Carli, Marcelo F.
中科院分区：
文献类型：
--
作者：
Dorbala, Sharmila;Park, Mi-Ae;Di Carli, Marcelo F.
本研究的主要目的是确定绝对定量 Tc-99m-焦磷酸指标与心脏淀粉样蛋白负荷的传统测量之间的相关性，并测量定量指标的观察者内重复性。方法：我们研究了 72 名接受 Tc-99m-焦磷酸盐 SPECT/CT 的患者，使用新型通用碲化镉锌 SPECT/CT 系统。这些研究的临床标准是视觉分级（0、1、2 和 3 级分别表示心肌摄取缺失、低于肋骨摄取、等于肋骨摄取或大于肋骨摄取）。 2 或以上的视觉等级被认为是积极的。计算 72 名患者的 SUVmax、SUVmean、心脏淀粉样蛋白活性（CAA；即 SUVmean x 左心室 [LV] 体积）和注射剂量百分比 (%ID)，并进行视觉分级。确定 4 个定量指标或视觉等级与 LV 质量指数 (LVMI)（以超声心动图上的体表面积为索引，67 名患者）之间的相关性。对于 11 名患者的子集，确定了视觉或定量指标与心脏 MRI 上的细胞外体积 (ECV) 之间的相关性。使用正态线性回归来比较 4 个定量指标中每一个指标与 LVMI 的标准化关联，作为淀粉样蛋白负荷的替代指标。接受者操作特征曲线分析用于确定定量指标的诊断准确性，并使用视觉分级作为参考标准。还确定了生成定量指标的观察者内可重复性。结果：所有 4 个定量指标均高度准确，用于诊断转甲状腺素蛋白心脏淀粉样变性的受试者工作特征曲线下面积均超过 0.96。 SUVmax、SUVmean、CAA、%ID 和视觉等级与 LVMI 呈中度正相关（%ID 的 r = 0.485），并且与 ECV 呈强正相关（尽管是在一个小队列中）（r = 0.873，SUVmax）。观察者内的重复性非常好，SUVmax、%ID 和 CAA 的变异系数小于 2%，SUVmean 的变异系数小于 3.8%。所有 4 个定量指标对 LVMI 的标准化影响均超过 0.324； %ID 的最大标准化效应为 0.485。结论：在这项首次（据我们所知）使用新型碲化镉锌 SPECT/CT 扫描仪对 Tc-99m-焦磷酸盐心脏成像进行的研究中，通过 Tc-99m-焦磷酸盐绝对定量测量的 SUVmax、SUVmean、CAA 和 %ID 与 LVMI 中度相关，并且与 ECV 强相关（尽管是在一个小队列中）。生成定量指标的观察者内部可重复性非常好。
The primary aims of this study were to determine the correlation between absolute quantitative Tc-99m-pyrophosphate metrics and traditional measures of cardiac amyloid burden and to measure the intraobserver repeatability of the quantitative metrics. Methods: We studied 72 patients who underwent Tc-99m-pyrophosphate SPECT/CT using a novel general-purpose cadmium-zinc-telluride-based SPECT/CT system. The clinical standard for these studies is visual grading (with grades of 0, 1, 2, and 3 indicating myocardial uptake absent, less than rib uptake, equal to rib uptake, or more than rib uptake, respectively). A visual grade of 2 or more was considered positive. For 72 patients, SUVmax, SUVmean, cardiac amyloid activity (CAA; i.e., SUVmean x left ventricular [LV] volume), and percentage injected dose (%ID) were calculated, and visual grading was performed. The correlation was determined between the 4 quantitative metrics or visual grades and the LV mass index (LVMI) (indexed to body surface area on echocardiography, 67 patients). For a subset of 11 patients, the correlation was determined between the visual or quantitative metrics and the extracellular volume (ECV) on cardiac MRI. Normal linear regression was used to compare the standardized association of each of the 4 quantitative metrics with LVMI, as a surrogate for amyloid burden. Receiver-operatingcharacteristic curve analysis was used to determine the diagnostic accuracy of quantitative metrics, using visual grading as the reference standard. The intraobserver repeatability of generating quantitative metrics was also determined. Results: All 4 quantitative metrics were highly accurate, with an area under the receiver-operatingcharacteristic curve of more than 0.96 for diagnosis of transthyretin cardiac amyloidosis. SUVmax, SUVmean, CAA, %ID, and visual grade were moderately positively correlated with LVMI (r = 0.485 for %ID) and strongly positively correlated, albeit in a small cohort, with ECV (r = 0.873, SUVmax). Intraobserver repeatability was excellent, with less than a 2% coefficient of variation for SUVmax, %ID, and CAA and 3.8% for SUVmean. All 4 quantitative metrics had a standardized effect of more than 0.324 on LVMI; the largest standardized effect was 0.485, for %ID. Conclusion: In this first (to our knowledge) study of Tc-99m-pyrophosphate cardiac imaging using a novel cadmiumzinc-telluride SPECT/CT scanner, SUVmax, SUVmean, CAA, and %ID measured by absolute quantitation of Tc-99m-pyrophosphate were moderately correlated with LVMI and strongly correlated, albeit in a small cohort, with ECV. The intraobserver repeatability of generating the quantitative metrics was excellent.