Lassen Martin L, Muzik Otto, Beyer Thomas, Hacker Marcus, Ladefoged Claes Nøhr, Cal-González Jacobo, Wadsak Wolfgang, Rausch Ivo, Langer Oliver, Bauer Martin
Center for Medical Physics and Biomedical Engineering, Medical University of ViennaVienna, Austria.
Department of Radiology, Detroit Medical Center, Children's Hospital of Michigan, Wayne State University School of MedicineDetroit, MI, United States.
Front Neurosci. 2017 Jul 17;11:396. doi: 10.3389/fnins.2017.00396. eCollection 2017.
The purpose of this study was to test the feasibility of migrating a quantitative brain imaging protocol from a positron emission tomography (PET)-only system to an integrated PET/MR system. Potential differences in both absolute radiotracer concentration as well as in the derived kinetic parameters as a function of PET system choice have been investigated. Five healthy volunteers underwent dynamic (R)-[C]verapamil imaging on the same day using a GE-Advance (PET-only) and a Siemens Biograph mMR system (PET/MR). PET-emission data were reconstructed using a transmission-based attenuation correction (AC) map (PET-only), whereas a standard MR-DIXON as well as a low-dose CT AC map was applied to PET/MR emission data. Kinetic modeling based on arterial blood sampling was performed using a 1-tissue-2-rate constant compartment model, yielding kinetic parameters (K and k) and distribution volume (V ). Differences for parametric values obtained in the PET-only and the PET/MR systems were analyzed using a 2-way Analysis of Variance (ANOVA). Comparison of DIXON-based AC (PET/MR) with emission data derived from the PET-only system revealed average inter-system differences of -33 ± 14% ( < 0.05) for the K parameter and -19 ± 9% ( < 0.05) for k. Using a CT-based AC for PET/MR resulted in slightly lower systematic differences of -16 ± 18% for K and -9 ± 10% for k. The average differences in V were -18 ± 10% ( < 0.05) for DIXON- and -8 ± 13% for CT-based AC. Significant systematic differences were observed for kinetic parameters derived from emission data obtained from PET/MR and PET-only imaging due to different standard AC methods employed. Therefore, a transfer of imaging protocols from PET-only to PET/MR systems is not straightforward without application of proper correction methods. www.clinicaltrialsregister.eu, identifier 2013-001724-19.
本研究的目的是测试将定量脑成像方案从仅正电子发射断层扫描（PET）系统迁移至集成式PET/MR系统的可行性。已研究了作为PET系统选择函数的绝对放射性示踪剂浓度以及衍生动力学参数方面的潜在差异。五名健康志愿者在同一天分别使用GE-Advance（仅PET）和西门子Biograph mMR系统（PET/MR）进行了动态（R）-[C]维拉帕米成像。PET发射数据使用基于透射的衰减校正（AC）图（仅PET）进行重建，而标准MR-DIXON以及低剂量CT AC图应用于PET/MR发射数据。基于动脉血采样的动力学建模使用单组织双速率常数房室模型进行，得出动力学参数（K和k）以及分布容积（V ）。使用双向方差分析（ANOVA）分析在仅PET系统和PET/MR系统中获得的参数值差异。基于DIXON的AC（PET/MR）与仅PET系统得出的发射数据比较显示，K参数的系统间平均差异为-33±14%（<0.05），k为-19±9%（<0.05）。对PET/MR使用基于CT的AC导致K的系统差异略低，为-16±18%，k为-9±10%。V 的平均差异，基于DIXON的AC为-18±10%（<0.05），基于CT的AC为-8±13%。由于采用了不同的标准AC方法，从PET/MR和仅PET成像获得的发射数据得出的动力学参数存在显著的系统差异。因此，在未应用适当校正方法的情况下，将成像方案从仅PET系统转移至PET/MR系统并非易事。 www.clinicaltrialsregister.eu，标识符2013-001724-19。
