Influence of collimator choice and simulated clinical conditions on 123I-MIBG heart/mediastinum ratios:: a phantom study
Influence of collimator choice and simulated clinical conditions on 123I-MIBG heart/mediastinum ratios:: a phantom study
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DOI：
10.1007/s00259-005-1810-3
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发表时间：
2005-09-01
影响因子：
9.1
通讯作者：
Sokole, EB
中科院分区：
文献类型：
--
作者：
Verberne, HJ;Feenstra, C;Sokole, EB
目的：I-123由于高能光子发射而出现成像问题。我们研究了准直器对I-123-MIBG心脏/纵隔比率(H/M比率)的影响。其次，我们模拟临床条件，评估了不同活性浓度对H/M比的影响。方法：玛瑙心模按三种顺序分别填充I-123：A，心脏和纵隔活动；B，添加肺活动；C，添加肝脏活动(方案I)。在方案II中，心肌和肝脏充满了从低到高的不同活性。对于每种情况，在西门子e.cam(SI)和通用电气Millennium VG(GE)系统上进行静态前平面和单光子发射计算机断层扫描研究，方案I使用低能量高分辨率和中能量(ME)准直器，方案II仅使用ME准直器。对于SI相机，应用了三能窗(Tew)散射校正。结果：由于肝脏活动的增加，散射和间隔穿透影响了平面H/M比率。对于ME准直器，这些影响不那么明显。虽然Tew散射校正增加了总体比率，但Tew修正并没有改善比率之间的相对差异。结论：对于半定量I-123-MIBG心肌研究的直接实施，我们建议使用无散射校正的ME准直仪。
Purpose: I-123 presents imaging problems owing to high-energy photon emission. We investigated the influence of collimators on I-123-MIBG heart/mediastinum ratios (H/M ratios). Secondly, we assessed the influence on H/M ratios of different activity concentrations, simulating clinical conditions. Thirdly, the value of scatter correction was assessed.Methods: The AGATE cardiac phantom was filled with I-123 in three sequential conditions: A, heart and mediastinal activity; B, adding lung activity; and C, adding liver activity (protocol I). In protocol II, myocardium and liver were filled with different activities ranging from low to high. For each condition, static anterior planar and single-photon emission computed tomography studies were acquired on a Siemens e.cam (SI) and a General Electric Millennium VG (GE) system, using low-energy high-resolution and medium-energy (ME) collimators for protocol I and only ME collimators for protocol II . For the SI camera, a triple energy window (TEW) scatter correction was applied.Results: Planar H/M ratios were influenced by scatter and septal penetration from increasing amounts of liver activity. These effects were less pronounced for ME collimators. Although the TEW scatter correction increased ratios overall, TEW correction did not improve the relative differences between the ratios. TEW correction therefore does not add any benefit to obtain an accurate reflection of myocardial activity concentrations.Conclusion: For straightforward implementation of semi-quantitative I-123-MIBG myocardial studies, we recommend the use of ME collimators without scatter correction.