Quiescent period respiratory gating for PET/CT
Quiescent period respiratory gating for PET/CT
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DOI：
10.1118/1.3480508
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发表时间：
2010-09-01
期刊：
影响因子：
3.8
通讯作者：
Kinahan, Paul
中科院分区：
文献类型：
--
作者：
Liu, Chi;Alessio, Adam;Kinahan, Paul
目的：为了将呼吸运动伪影降至最低，本研究提出了静止期选通（QPG）方法，该方法从呼气末静止期提取正电子发射断层扫描（PET）数据，并形成一个运动减少且信噪比特性提高的单一PET帧。
方法：提出并评估了两种QPG方法。基于直方图的静止期选通（H - QPG）根据呼吸位移信号直方图的一个窗口提取一部分PET数据。基于周期的静止期选通（C - QPG）提取呼吸位移信号低于每个单独呼吸周期最大振幅特定阈值的数据。在21个氟脱氧葡萄糖 - PET/CT患者数据集（包含31个胸部和腹部病变）以及由1295个不同患者呼吸轨迹驱动的计算机模拟中，将两种QPG方法的性能与非选通和五区间相位选通图像进行了比较。以病变的最大标准摄取值（SUVmax）以及每个选通中包含的计数比例（作为图像噪声的替代指标）来评估图像质量。
结果：对于所有选通方法，当每个选通中包含的计数比例小于50%时，图像噪声会人为地增加SUVmax。虽然模拟数据表明H - QPG优于C - QPG，但在患者数据中，H - QPG和C - QPG方法在定量 - 噪声权衡方面结果相似。与非选通图像相比，两种QPG方法都能显著提高病变的SUVmax。与五区间相位选通相比，QPG方法在产生相似的SUVmax改善的同时，能获得显著更大的计数比例。对于病变静止期较长的患者，两种QPG方法都能提高病变的SUVmax。
结论：与非选通和相位选通图像相比，QPG方法所得到的图像运动模糊更少，并且在SUVmax和计数比例之间有更好的平衡。用于呼吸运动补偿的QPG方法可以在噪声增加最小的情况下有效地提高肿瘤定量。（C）2010美国医学物理学家协会。[DOI: 10.1118/1.3480508]
Purpose: To minimize respiratory motion artifacts, this work proposes quiescent period gating (QPG) methods that extract PET data from the end-expiration quiescent period and form a single PET frame with reduced motion and improved signal-to-noise properties.Methods: Two QPG methods are proposed and evaluated. Histogram-based quiescent period gating (H-QPG) extracts a fraction of PET data determined by a window of the respiratory displacement signal histogram. Cycle-based quiescent period gating (C-QPG) extracts data with a respiratory displacement signal below a specified threshold of the maximum amplitude of each individual respiratory cycle. Performances of both QPG methods were compared to ungated and five-bin phase-gated images across 21 FDG-PET/CT patient data sets containing 31 thorax and abdomen lesions as well as with computer simulations driven by 1295 different patient respiratory traces. Image quality was evaluated in terms of the lesion SUVmax and the fraction of counts included in each gate as a surrogate for image noise.Results: For all the gating methods, image noise artifactually increases SUVmax when the fraction of counts included in each gate is less than 50%. While simulation data show that H-QPG is superior to C-QPG, the H-QPG and C-QPG methods lead to similar quantification-noise tradeoffs in patient data. Compared to ungated images, both QPG methods yield significantly higher lesion SUVmax. Compared to five-bin phase gating, the QPG methods yield significantly larger fraction of counts with similar SUVmax improvement. Both QPG methods result in increased lesion SUVmax for patients whose lesions have longer quiescent periods.Conclusions: Compared to ungated and phase-gated images, the QPG methods lead to images with less motion blurring and an improved compromise between SUVmax and fraction of counts. The QPG methods for respiratory motion compensation could effectively improve tumor quantification with minimal noise increase. (C) 2010 American Association of Physicists in Medicine. [DOI: 10.1118/1.3480508]