Variability in Heart-to-Mediastinum Ratio from Planar 123I-MIBG Images of a Thorax Phantom for 6 Common γ-Camera Models
Variability in Heart-to-Mediastinum Ratio from Planar 123I-MIBG Images of a Thorax Phantom for 6 Common γ-Camera Models
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DOI：
10.2967/jnmt.117.196055
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发表时间：
2017-12-01
影响因子：
1.3
通讯作者：
Cella, Patrick
中科院分区：
文献类型：
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作者：
Owenius, Rikard;Zanette, Michelle;Cella, Patrick
I-123-碘苯胍（I-123-MIBG）平面图像上心脏与纵隔（H/M）比值≥ 1.6时，心力衰竭患者发生不良心脏事件的风险较低。这项4期研究使用标准化体模评估了使用市售双头I-123-MIBG平面心脏成像的H/M比测定中的相机间、相机内和头间变异性。相机方法：研制可填充式胸腔体模，模拟I-123-MIBG的典型摄取。体模在参考相机上的标称H/M比为1.6。研究中使用的商业相机是双头的，能够进行90度心脏成像。目标样本量为每种相机型号8件装置（示例）。两名成像技术人员独立分析了来自胸部体模的模拟I-123-MIBG摄取的平面图像。H/M是心脏和纵隔感兴趣区域的每像素平均计数的比率。通过与参考摄像机上的H/M比进行比较，确定每个摄像机型号的主要终点，即来自头部1的H/M比的摄像机间变异性。主要分析仅包括至少测试了8个单元的摄像机（n >= 8）。还评价了H/M比值的摄像机内和头间变异性。结果：研究了9种相机模型。平均H/M比值范围为1.342 - 1.677。使用混合模型、重复测量分析的主要分析（6种相机型号）显示，任何相机型号与参考相机之间的H/M比均无显著差异。在8个或更多单位的相机型号中，H/M比的相机内变异性（头部1）较高，SD范围为0.0455至0.1193。头间变异性较低（头间差异的SD为0.017-0.074）。结论：常用。照相机从模拟的I-123-MIBG体模图像产生的H/M比与参考照相机上的H/M比没有显著差异。这一发现表明，先前涉及许多不同临床地点和相机型号的I-123-MIBG临床试验的结果是有效的。鼓励在I-123-MIBG成像的H/M结果用于对心力衰竭患者的风险进行分类之前，使用I-123平面体模评估给定相机单元的性能。
A heart-to-mediastinum (H/M) ratio of 1.6 or greater on planar I-123-iobenguane (I-123-MIBG) images identifies heart failure patients at low risk of experiencing an adverse cardiac event. This phase-4 study used standardized phantoms to assess the intercamera, intracamera, and interhead variability in H/M ratio determinations from planar cardiac I-123-MIBG imaging using commercially available, dual-head.-cameras. Methods: A fillable thorax phantom was developed to simulate the typical uptake of I-123-MIBG. The phantom had a nominal H/M ratio of 1.6 on the reference camera. Commercial cameras used in the study were dual-head and capable of 90 degrees configuration for cardiac imaging. The target sample size was 8 units (examples) per camera model. Two imaging technologists independently analyzed planar images of simulated I-123-MIBG uptake from the thorax phantom. H/M was the ratio of the average counts per pixel of the heart and mediastinum regions of interest. The primary endpoint, intercamera variability in H/M ratio from head 1, was determined for each camera model via comparison with the H/M ratio on the reference camera. Only cameras with at least 8 units tested (n >= 8) were included in the primary analysis. Intracamera and interhead variability in the H/M ratio were also evaluated. Results: Nine camera models were studied. The mean H/M ratio ranged from 1.342 to 1.677. The primary analysis (6 camera models) using a mixed-model, repeated-measures analysis showed no significant difference in H/M ratio between any camera model and the reference camera. Intracamera variability (head 1) in the H/M ratio among camera models with 8 units or more was high, with SDs ranging from 0.0455 to 0.1193. Interhead variability was low (SDs of the interhead difference, 0.017-0.074). Conclusion: Commonly used.-cameras produced H/M ratios from simulated I-123-MIBG phantom images that were not significantly different from those on the reference camera. This finding indicates that the results of previous clinical trials of I-123-MIBG, involving many different clinical sites and camera models, are valid. The assessment of the performance of a given camera unit using an I-123 planar phantom before H/M results from I-123-MIBG imaging are used for classifying risk in heart failure patients is encouraged.