Thomas M Allan, Meier Joseph G, Mawlawi Osama R, Sun Peng, Pan Tinsu
Department of Imaging Physics, UT MD Anderson Cancer Center, Houston, TX 77030, United States of America.
Department of Medical Physics, University of Wisconsin, Madison, WI 53726, United States of America.
Phys Med Biol. 2022 Apr 8;67(8). doi: 10.1088/1361-6560/ac5f73.
. Data-driven gating (DDG) can address patient motion issues and enhance PET quantification but suffers from increased image noise from utilization of <100% of PET data. Misregistration between DDG-PET and CT may also occur, altering the potential benefits of gating. Here, the effects of PET acquisition time and CT misregistration were assessed with a combined DDG-PET/DDG-CT technique.. In the primary PET bed with lesions of interest and likely respiratory motion effects, PET acquisition time was extended to 12 min and a low-dose cine CT was acquired to enable DDG-CT. Retrospective reconstructions were created for both non-gated (NG) and DDG-PET using 30 s to 12 min of PET data. Both the standard helical CT and DDG-CT were used for attenuation correction of DDG-PET data. SUV, SUV, and CNR were compared for 45 lesions in the liver and lung from 27 cases.. For both NG-PET (= 0.0041) and DDG-PET (= 0.0028), only the 30 s acquisition time showed clear SUVbias relative to the 3 min clinical standard. SUVshowed no bias at any change in acquisition time. DDG-PET alone increased SUVby 15 ± 20% (< 0.0001), then was increased further by an additional 15 ± 29% (= 0.0007) with DDG-PET/CT. Both 3 min and 6 min DDG-PET had lesion CNR statistically equivalent to 3 min NG-PET, but then increased at 12 min by 28 ± 48% (= 0.0022). DDG-PET/CT at 6 min had comparable counts to 3 min NG-PET, but significantly increased CNR by 39 ± 46% (< 0.0001).. 50% counts DDG-PET did not lead to inaccurate or biased SUV-increased SUV resulted from gating. Improved registration from DDG-CT was equally as important as motion correction with DDG-PET for increasing SUV in DDG-PET/CT. Lesion detectability could be significantly improved when DDG-PET used equivalent counts to NG-PET, but only when combined with DDG-CT in DDG-PET/CT.
数据驱动门控（DDG）可以解决患者运动问题并提高PET定量分析，但由于仅使用了不到100%的PET数据，会导致图像噪声增加。DDG-PET与CT之间也可能发生配准错误，从而改变门控的潜在益处。在此，采用联合DDG-PET/DDG-CT技术评估了PET采集时间和CT配准错误的影响。在存在感兴趣病变且可能有呼吸运动影响的主PET床位，将PET采集时间延长至12分钟，并采集低剂量电影CT以实现DDG-CT。使用30秒至12分钟的PET数据对非门控（NG）和DDG-PET进行回顾性重建。标准螺旋CT和DDG-CT均用于DDG-PET数据的衰减校正。比较了27例患者肝脏和肺部45个病变的SUV、SUV和CNR。对于NG-PET（=0.0041）和DDG-PET（=0.0028），只有30秒的采集时间相对于3分钟的临床标准显示出明显的SUV偏差。在采集时间的任何变化下，SUV均无偏差。单独的DDG-PET使SUV增加了15±20%（<0.0001），然后在DDG-PET/CT时又进一步增加了15±29%（=0.0007）。3分钟和6分钟的DDG-PET的病变CNR在统计学上与3分钟的NG-PET相当，但在12分钟时增加了28±48%（=0.0022）。6分钟的DDG-PET/CT的计数与3分钟的NG-PET相当，但CNR显著增加了39±46%（<0.0001）。50%计数的DDG-PET不会导致SUV不准确或有偏差——SUV增加是由门控导致的。对于在DDG-PET/CT中增加SUV而言，DDG-CT改善的配准与DDG-PET的运动校正同样重要。当DDG-PET使用与NG-PET等量的计数时，病变可检测性可显著提高，但前提是在DDG-PET/CT中与DDG-CT相结合。
