PET Image Quality Improvement for Simultaneous PET/MRI with a Lightweight MRI Surface Coil.
PET Image Quality Improvement for Simultaneous PET/MRI with a Lightweight MRI Surface Coil.
复制标题
使用轻型 MRI 表面线圈提高同步 PET/MRI 的 PET 图像质量。
DOI：
10.1148/radiol.2020200967
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发表时间：
2021
期刊：
影响因子：
19.7
通讯作者：
McMillan,AlanB
中科院分区：
文献类型：
--
作者：
Deller,TimothyW;Mathew,NicholasK;Hurley,SamuelA;Bobb,ChadM;McMillan,AlanB
背景在同步 PET/MRI 过程中，放置在患者身上的柔性 MRI 表面线圈经常在 PET 衰减校正处理中被省略，从而导致 PET 图像中的量化偏差。目的通过在体模和体内研究中使用最近开发的轻量级 MRI 线圈技术用于前部阵列 (AA) 表面线圈，确定潜在的 PET 图像质量改进。材料和方法使用 PET/CT 扫描仪在 3 下进行体模研究和前瞻性体内研究。条件：(a)无 MRI 表面线圈（参考标准），(b)传统 AA 线圈，(c)轻型 AA 线圈。 AA 线圈未用于模拟临床 PET/MRI 的衰减校正处理。 对于模型研究，在有或没有飞行时间 (TOF) 的情况下重建 PET 图像，以评估量化准确性和均匀性。 体内研究由 10 名参加 PET/CT 肿瘤检查的参与者（平均年龄 66 岁 ± 10 [标准差]；六名男性）组成，他们在 2019 年 10 月至 2020 年 2 月期间接受了成像。通过将平均肝脏感兴趣区域标准化摄取值与无线圈参考标准进行比较，进行图像量化偏差（定义为平均值的标准误差）评估。使用 Wilcoxon 符号秩检验来确定显着性。结果对于 TOF 和非 TOF，体模研究分别显示，传统 AA 线圈的平均 PET 定量偏差为 -9.0% 和 -8.6%，而轻量级 AA 线圈的平均 PET 定量偏差为 -4.3% 和 -4.0%。变异系数从传统 AA 线圈的 4.3% 和 6.2% 减少到轻量级 AA 线圈的 2.1% 和 2.7%，这表明轻量级线圈的均匀性优势在有 TOF 重建时比没有 TOF 重建时更大。对于体内研究，传统 AA 线圈的平均肝脏标准化摄取值误差为 -5.9%（P= .002 对比无线圈），轻量级 AA 线圈的平均肝脏标准化摄取值误差为 -2.4%（P= .004 对比无线圈）。 结论 与传统线圈相比，轻型前阵列线圈将 PET 图像量化偏差降低了 50% 以上。使用轻质线圈和执行基于飞行时间的重建都减少了误差的变化。© RSNA，2020网上出现了早期的错误版本。本文已于 2021 年 1 月 4 日更正。
BackgroundDuring simultaneous PET/MRI, flexible MRI surface coils that lay on the patient are often omitted from PET attenuation correction processing, leading to quantification bias in PET images.PurposeTo identify potential PET image quality improvement by using a recently developed lightweight MRI coil technology for the anterior array (AA) surface coil in both a phantom and in vivo study.Materials and MethodsA phantom study and a prospective in vivo study were performed with a PET/CT scanner under three conditions:(a)no MRI surface coil (standard of reference),(b)traditional AA coil, and(c)lightweight AA coil. AA coils were not used in attenuation correction processing to emulate clinical PET/MRI. For the phantom study, PET images were reconstructed with and without time of flight (TOF) to assess quantification accuracy and uniformity. The in vivo study consisted of 10 participants (mean age, 66 years ± 10 [standard deviation]; six men) referred for a PET/CT oncologic examination who had undergone imaging between October 2019 and February 2020. Assessment of image quantification bias (defined as the standard error of the mean values) was conducted by comparing mean liver region of interest standardized uptake values with the no-coil standard of reference. A Wilcoxon signed-rank test was used to establish significance.ResultsFor TOF and non-TOF, respectively, the phantom study revealed a mean PET quantification bias of −9.0% and −8.6% with the traditional AA coil and a mean PET quantification bias of −4.3% and −4.0% with the lightweight AA coil. The coefficients of variation reduced from 4.3% and 6.2% with the traditional AA coil to 2.1% and 2.7% with the lightweight AA coil, which demonstrated a homogeneity benefit from the lightweight coil that was greater with, versus without, TOF reconstruction. For the in vivo study, the mean liver standardized uptake value error was −5.9% with the traditional AA coil (P= .002 vs no coil) and −2.4% with the lightweight AA coil (P= .004 vs no coil).ConclusionThe lightweight anterior array coil reduced PET image quantification bias by more than 50% compared with the traditional coil. Using the lightweight coil and performing time of flight–based reconstruction each reduced the variation of error.© RSNA, 2020An earlier incorrect version appeared online. This article was corrected on January 4, 2021.