Validation of MR-Based Attenuation Correction of a Newly Released Whole-Body Simultaneous PET/MR System
Validation of MR-Based Attenuation Correction of a Newly Released Whole-Body Simultaneous PET/MR System
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新发布的全身同步 PET/MR 系统基于 MR 的衰减校正的验证
DOI：
10.1155/2019/8213215
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发表时间：
2019-11-28
影响因子：
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通讯作者：
Shi, Hongcheng
中科院分区：
文献类型：
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作者：
Liu, Guobing;Cao, Tuoyu;Shi, Hongcheng
本研究的目的是通过在体模研究和患者研究中使用基于MR的衰减校正（MRAC），验证新发布的同步正电子发射断层扫描（PET）/磁共振成像（MRI）扫描仪的定量性能。测试并比较了不同硬件配置下体模的PET/MRI图像均匀性。对30例患者进行了2-脱氧-2-[18 F]氟-D-葡萄糖（18 F-FDG）PET/计算机断层扫描（CT）和随后的PET/MRI检查。使用MRAC（PETMR）、基于CT的衰减图（μ图，PETCT）和PET/CT的分段CT μ图（PETCTSeg）校正PET/MRI的PET图像。比较了3组PET在主要器官（骨、肝和肺）和52个FDG-亲合病变（包括软组织病变和骨病变）中的标准化摄取值（SUV）。结果表明，PET/MRI在不同配置下的PET成像均匀性良好（<8.8%）。3组PET之间的SUV差异因器官和病变类型而异。具体而言，PETMR和PETCT之间SUV的平均相对差异如下：− 18.8%，骨（SUV平均值）; − 8.0%，肝（SUV平均值）; − 12.2%，肺（SUV平均值）; − 18.1%，骨病变（SUV平均值）; − 13.3%，骨病变（SUV最大值）; − 8.2%，软组织病变（SUV平均值）;和− 7.3%，软组织病变（SUV最大值）。PETMR和PETCTSeg之间的平均相对差异如下：− 19.0%，骨（SUV平均值）; − 3.5%，肝（SUV平均值）; − 3.3%，肺（SUV平均值）; − 19.3%，骨病变（SUV平均值）; − 17.5%，骨病变（SUV最大值）; − 5.5%，软组织病变（SUV平均值）;和− 4.4%，软组织病变（SUV最大值）。PETMR与PETCT的SUV值差异均大于PETMR与PETCTSeg的SUV值差异，在软组织和软组织病变中差异均有统计学意义（P < 0.001），但在骨和骨病变中差异无统计学意义。总之，新发布的PET/MR系统中的MRAC在大多数组织中是准确的，与PET/CT相比，SUV偏差通常小于10%。然而，在骨中，低估可能是实质性的，这可能部分归因于基于MR的μ图的分割。
The aim of this study was to validate quantitative performance of a newly released simultaneous positron emission tomography (PET)/magnetic resonance imaging (MRI) scanner, by using MR-based attenuation correction (MRAC), both in phantom study and in patient study. PET/MRI image uniformities of a phantom under different hardware configurations were tested and compared. Thirty patients were examined with 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG) PET/computed tomography (CT) and subsequent PET/MRI. PET images from PET/MRI were corrected with MRAC (PETMR), CT-based attenuation maps (μ-maps, PETCT), and segmented CT μ-maps (PETCTSeg) derived from PET/CT. Standardized uptake values (SUVs) were compared among the 3 sets of PET in main organs (bone, liver and lung) and in 52 FDG-avid lesions, including soft-tissue lesions and bone lesions. The result showed that PET imaging uniformities of PET/MRI under different configurations were good (<8.8%). The SUV differences among the 3 sets of PET varied with organs and lesion types. In detail, the mean relative differences of SUV between PETMR and PETCT were as follows: −18.8%, bone (SUVmean); −8.0%, liver (SUVmean); −12.2%, lung (SUVmean); −18.1%, bone lesions (SUVmean); −13.3%, bone lesions (SUVmax); −8.2%, soft-tissue lesions (SUVmean); and −7.3%, soft-tissue lesions (SUVmax). The mean relative differences between PETMR and PETCTSeg were as follows: −19.0%, bone (SUVmean); −3.5%, liver (SUVmean); −3.3%, lung (SUVmean); −19.3%, bone lesions (SUVmean); −17.5%, bone lesions (SUVmax); −5.5%, soft-tissue lesions (SUVmean); and −4.4%, soft-tissue lesions (SUVmax). The differences of SUV between PETMR and PETCT were larger than those between PETMR and PETCTSeg, in both soft tissue and soft-tissue lesions (P < 0.001), but not in bone or bone lesions. In conclusion, MRAC in the newly released PET/MR system is accurate in most tissues, with SUV deviations being generally less than 10%, compared to PET/CT. In bone, however, underestimations can be substantial, which may be partially attributed to segmentation of the MR-based μ-maps.