Hamdi Mahdjoub, Natsuaki Yutaka, Wangerin Kristen A, An Hongyu, St James Sarah, Kinahan Paul E, Sunderland John J, Larson Peder E Z, Hope Thomas A, Laforest Richard
Washington University in St. Louis, Mallinckrodt Institute of Radiology, St. Louis, Missouri, United States.
University of California San Francisco, Department of Radiation Oncology, San Francisco, California, United States.
J Med Imaging (Bellingham). 2021 Sep;8(5):056001. doi: 10.1117/1.JMI.8.5.056001. Epub 2021 Sep 20.
One major challenge facing simultaneous positron emission tomography (PET)/ magnetic resonance imaging (MRI) is PET attenuation correction (AC) measurement and evaluation of its accuracy. There is a crucial need for the evaluation of current and emergent PET AC methodologies in terms of absolute quantitative accuracy in the reconstructed PET images. To address this need, we developed and evaluated a lesion insertion tool for PET/MRI that will facilitate this evaluation process. This tool was developed for the Biograph mMR and evaluated using phantom and patient data. Contrast recovery coefficients (CRC) from the NEMA IEC phantom of synthesized lesions were compared to measurements. In addition, SUV biases of lesions inserted in human brain and pelvis images were assessed from PET images reconstructed with MRI-based AC (MRAC) and CT-based AC (CTAC). For cross-comparison PET/MRI scanners AC evaluation, we demonstrated that the developed lesion insertion tool can be harmonized with the GE-SIGNA lesion insertion tool. About CRC curves difference between simulation and measurement was achieved. An average of 1.6% between harmonized simulated CRC curves obtained with mMR and SIGNA lesion insertion tools was achieved. A range of to 12% MRAC to CTAC SUV bias was respectively achieved in the vicinity and inside bone tissues in patient images in two anatomical regions, the brain, and pelvis. A lesion insertion tool was developed for the Biograph mMR PET/MRI scanner and harmonized with the SIGNA PET/MRI lesion insertion tool. These tools will allow for an accurate evaluation of different PET/MRI AC approaches and permit exploration of subtle attenuation correction differences across systems.
同时进行正电子发射断层扫描（PET）/磁共振成像（MRI）面临的一个主要挑战是PET衰减校正（AC）测量及其准确性评估。在重建的PET图像中，迫切需要从绝对定量准确性方面评估当前和新兴的PET AC方法。为满足这一需求，我们开发并评估了一种用于PET/MRI的病变插入工具，该工具将有助于这一评估过程。此工具是为Biograph mMR开发的，并使用体模和患者数据进行了评估。将合成病变的NEMA IEC体模的对比度恢复系数（CRC）与测量值进行了比较。此外，还从基于MRI的AC（MRAC）和基于CT的AC（CTAC）重建的PET图像中评估了插入人脑和骨盆图像中的病变的SUV偏差。为了进行交叉比较PET/MRI扫描仪的AC评估，我们证明了所开发的病变插入工具可以与GE-SIGNA病变插入工具协调一致。实现了模拟和测量之间的CRC曲线差异。使用mMR和SIGNA病变插入工具获得的协调模拟CRC曲线之间平均相差1.6%。在大脑和骨盆这两个解剖区域的患者图像中，在骨组织附近和内部，MRAC到CTAC的SUV偏差分别达到了到12%的范围。为Biograph mMR PET/MRI扫描仪开发了一种病变插入工具，并与SIGNA PET/MRI病变插入工具进行了协调。这些工具将能够准确评估不同的PET/MRI AC方法，并允许探索不同系统之间细微的衰减校正差异。
