Gamma shielding materials for MR-compatible PET
Gamma shielding materials for MR-compatible PET
复制标题
适用于 MR 兼容 PET 的伽马屏蔽材料
DOI：
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
P. Marsden
中科院分区：
文献类型：
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作者：
D. Strul;D. Cash;S. Keevil;P. Halsted;S. Williams;P. Marsden
至于标准的正电子发射断层扫描(PET)扫描仪，与MR兼容的PET扫描仪将需要伽马屏蔽以抑制PET视场(FOV)外活动的影响。合适的材料必须具有非常特殊的性质，包括接近水的磁性，高密度，高原子序数，理想情况下是低导电性。为了确定潜在的合适材料，我们根据现有的磁性和屏蔽性能数据选择了几个基于重金属的候选材料。这些材料包括几种非铁磁性金属和金属氧化物，两种闪烁晶体(锗酸铋和钨酸铅)和两种金属/环氧化合物。这些材料的磁共振成像(MRI)兼容性在不同条件下进行了评估，包括在人类和小动物MRI扫描仪上。同时，我们评估了最有希望的候选者在661keV的屏蔽效率。这些实验表明，设计与MR兼容的伽马屏蔽体有多种可能性。铅具有可接受的磁兼容性，但会导致大量与导电有关的伪影。重金属基矿物是完全绝缘的，热压一氧化铅表现出良好的MR兼容性和良好的屏蔽性能。其他可能性包括使用铅基粉末和重金属氧化物复合材料。
As for standard positron emission tomography (PET) scanners, MR-compatible PET scanners will require gamma shielding to suppress the influence of activity outside the PET field of view (FOV). Suitable materials must have very specific properties, including magnetic properties close to those of water, high density, high atomic number, and ideally a low conductivity. In order to identify potential suitable materials, we have selected several heavy-metal-based candidates based on the available data for magnetic and shielding properties. These materials include several nonferromagnetic metals and metal oxides, two scintillating crystals (bismuth germanate and lead tungstate) and two metal/epoxy compounds. The magnetic resonance imaging (MRI) compatibility of these materials was assessed under various conditions, both on a human and a small-animal MRI scanner. In parallel, we assessed the shielding efficiency at 661 keV of the most promising candidates. These experiments showed that there is a range of possibilities for the design of MR-compatible gamma shields. Lead has acceptable magnetic compatibility but can induce significant conductivity-related artefacts. Heavy-metal-based minerals are fully insulating and hot-pressed lead monoxide showed good MR compatibility combined with good shielding properties. Other possibilities include the use of lead based powders and heavy-metal oxide composites.
MRI 梯度场中样本功率损失的分析。
影响因子：
3.8
作者：
Harpen,MD
通讯作者：
Harpen,MD