Pollard Alyssa C, de la Cerda Jorge, Schuler F William, Kingsley Charles V, Gammon Seth T, Pagel Mark D
Department of Chemistry, Rice University, Houston, TX, USA.
Department of Cancer Systems Imaging, MD Anderson Cancer Center, Houston, TX, USA.
EJNMMI Phys. 2022 Oct 8;9(1):70. doi: 10.1186/s40658-022-00483-x.
PET/MRI is an attractive imaging modality due to the complementary nature of MRI and PET. Obtaining high quality small animal PET/MRI results is key for the translation of novel PET/MRI agents and techniques to the radiology clinic. To obtain high quality imaging results, a hybrid PET/MRI system requires additional considerations beyond the standard issues with separate PET and MRI systems. In particular, researchers must understand how their PET system affects the MR acquisitions and vice versa. Depending on the application, some of these effects may substantially influence image quality. Therefore, the goal of this report is to provide guidance, recommendations, and practical experiments for implementing and using a small animal PET/MRI instrument.
Various PET and MR image quality parameters were tested with their respective modality alone and in the presence of both systems to determine how the combination of PET/MRI affects image quality. Corrections and calibrations were developed for many of these effects. While not all image characteristics were affected, some characteristics such as PET quantification, PET SNR, PET spatial resolution, PET partial volume effects, and MRI SNR were altered by the presence of both systems.
A full exploration of a new PET/MRI system before performing small animal PET/MRI studies is beneficial and necessary to ensure that the new instrument can produce highly accurate and precise PET/MR images.
由于MRI和PET的互补特性，PET/MRI是一种有吸引力的成像方式。获得高质量的小动物PET/MRI结果是将新型PET/MRI药物和技术转化到放射科临床应用的关键。为了获得高质量的成像结果，与单独的PET和MRI系统的标准问题相比，混合PET/MRI系统需要更多的考虑因素。特别是，研究人员必须了解他们的PET系统如何影响MR采集，反之亦然。根据应用情况，其中一些影响可能会对图像质量产生重大影响。因此，本报告的目的是为实施和使用小动物PET/MRI仪器提供指导、建议和实际实验。
分别对PET和MR各自的成像方式以及在两个系统同时存在的情况下，测试了各种PET和MR图像质量参数，以确定PET/MRI的组合如何影响图像质量。针对其中许多影响开发了校正和校准方法。虽然并非所有图像特征都受到影响，但一些特征，如PET定量、PET信噪比、PET空间分辨率、PET部分容积效应和MRI信噪比，会因两个系统同时存在而改变。
在进行小动物PET/MRI研究之前，对新的PET/MRI系统进行全面探索是有益且必要的，以确保新仪器能够产生高度准确和精确的PET/MR图像。
