Quantitative analysis of different MR sequences in precise dynamic reconstruction of
ToF PET/MR by integrated simultaneous acquisition
WANG Bo1, LIU Chang-ping1, ZHAI Wei1, ZHANG Xin1, CHEN Zhong-wei2, XIN Jun1
1. Department of Radiology and Nuclear Medicine, Shengjing Hospital, China Medical University, Shenyang 110004, China;
2. GE Healthcare(China), Beijing 100176, China
Abstract：Objective: To analyze whether different MR sequences have an effect on PET uptake by measuring the difference in SUV values of PET images after different sequences of MR pelvic reconstruction in integrated ToF PET/MR. Methods: A retrospective collection of 15 patients with uterine malignancies(including 11 cases of cervical cancer and 4 cases of endometrial cancer) was performed on PET/MR pelvic local scan. The total scan time was 20 mins. The MR scan sequences include OAX T2WI, OAX T2WI fs, SAG T1WI, SAG T2WI fs, COR T2WI, OAX fs DWI 1000, OAX T2*WI map. According to the scanning time of different sequences of MR, the PET images were reconstructed in exactly same time as the MR scanning sequences, and the SUVmax, SUVmean and background SUVmax and SUVmean of the segmented PET images corresponding to the MR scanning sequences were measured. In order to avoid the influence of time duration, the PET image was reconstructed according to the shortest scanning time of the same scanning direction sequence, and the lesion SUVmax, SUVmean and background SUVmax, SUVmean values of the PET image after short-term reconstruction are recorded, and the normal scanning time corresponding to MR is recorded. The PET image SUV values were compared. Objective statistical analysis and subjective evaluation were performed on the above results. Results: The lesions and background SUVmax and SUVmean values of the segmented PET images corresponding to the MR sequence were measured after dynamic reconstruction. There was no significant difference between SUVmax and SUVmean in normal tissues P>0.05; there were significant differences between SUVmax and SUVmean in different sequences of lesions and non-synchronized whole segments(SUVmax and SUVmean, P<0.05), and at the background, there was no significant difference between all sequences and the non-synchronized whole SUVmax and SUVmean(P>0.05). There was no significant difference in SUVmax and SUVmean between the PET obtained by short-term reconstruction and the PET dynamically reconstructed by MR(P>0.05). According to the international standard principles of the five score levels, the subjective scores of the two radiologists for the diagnosis were ≥4 points. Conclusion: The SUV values at the lesion location with different sequences(including functional sequences DWI and R2*WI) are not equivalent with the entire SUV values. It is more accurate to use the segmental dynamic reconstruction, and the quantitative SUV at the background position can represent the entire SUV value. On the subjective reading, the whole PET and segmented reconstructed PET images can be substituted for each other.
王 搏1，刘长平1，翟 伟1，张 新1，陈忠维2，辛 军1. 一体化ToF PET/MR盆腔扫描MR不同序列的
精准动态重建对于PET图像定量影响分析[J]. 中国临床医学影像杂志, 2020, 31(7): 512-516.
WANG Bo1, LIU Chang-ping1, ZHAI Wei1, ZHANG Xin1, CHEN Zhong-wei2, XIN Jun1. Quantitative analysis of different MR sequences in precise dynamic reconstruction of
ToF PET/MR by integrated simultaneous acquisition. JOURNAL OF CHINA MEDICAL IMAGING, 2020, 31(7): 512-516.
[1]Antoch G, Bockisch A. Combined PET/MRI: a new dimension in whole-body oncology imaging[J]. Eur J Nucl Med Mol Imaging, 2009, 36(Suppl 1): S113-120.
[2]Bailey DL, Pichler BJ, Gückel B, et al. Combined PET/MRI: multi-modality multi-parametric imaging is here[J]. Mol Imaging Biol, 2015, 17(5): 595-608.
[3]Judenhofer MS, Wehrl HF, Newport DF, et al. Simultaneous PET-MRI: a new approach for functional and morphological imaging[J]. Nat Med, 2008, 14(4): 459-465.
[4]Minamimoto R, Levin C, Jamali M, et al. Improvements in PET image quality in time of flight(TOF) simultaneous PET/MRI[J]. Mol Imaging Biol, 2016, 18(5): 776-781.
[5]Surti S. Update on time-of-flight PET imaging[J]. J Nucl Med, 2015, 56(1): 98-105.
[6]Surti S, Karp JS. Advances in time-of-flight PET[J]. Phys Med, 2016, 32(1): 12-22.
[7]Vandenberghe S, Mikhaylova E, D’Hoe E, et al. Recent developments in time-of-flight PET[J]. Ejnmmi Phys, 2016, 3(1): 3.
[8]卢洁，赵国光. 一体化PET\MR操作规范和临床应用[M]. 北京：人民卫生出版社，2017：11-12.
[9]Ter Voert EEGW, Veit-Haibach P, Ahn S, et al. Clinical evaluation of TOF versus non-TOF on PET artifacts in simultaneous PET/MR: a dual centre experience[J]. Eur J Nucl Med Mol Imaging, 2017, 44(7): 1223-1233.
[10]Wu H, Dimitrakopoulou-Strauss A, Heichel TO, et al. Quantitative evaluation of skeletal tumours with dynamic FDG PET: SUV in comparison to Patlak analysis[J]. Eur J Nucl Med, 2014, 28(6): 704-710.
[11]Herzog H, Lerche C. Advances in clinical PET/MRI in strumentation[J]. PET Clin, 2016, 11(2): 95-103.
[12]Oda K, Toyama H, Uemura K, et al. Comparison of parametric FBP and OS-EM reconstruction algorithm images for PET dynamic study[J]. Ann Nucl Med, 2001, 15(5): 417-423.
[13]Pichler B, Wehrl HF, Kolb A, et al. PET/MRI: The Next Generation of Multimodality Imaging?[J]. Sem Nucl Med, 2008, 38(3): 199-208.
