Mitigation of T1 impact for unbiased tumor magnetic resonance amide proton transfer imaging at 3T

作者：Zhou Liu, Qian Yang, Haizhou Liu, Honghong Luo, Yijia Zheng, Dehong Luo, Yin Wu · 发表于：Radiology Advances · 年份：2025 · DOI：10.1093/radadv/umaf011 · 被引用次数：3 · 研究领域：Lanthanide and Transition Metal Complexes、Advanced MRI Techniques and Applications、Medical Imaging Techniques and Applications

Abstract Background Amide proton transfer (APT), a specific type of chemical exchange saturation transfer (CEST) MRI, has proved valuable in tumor diagnosis and characterization by detecting mobile protein/peptides in cancerous tissues. However, T1 confounds CEST measurements, leading to reduced specificity to amides and potential misinterpretation of APT imaging. Purpose The study aimed to investigate the feasibility of the quasi-steady-state (QUASS)-based apparent exchange-dependent relaxation (AREX) analysis in correcting T1 for unbiased tumor APT MRI at 3T. Materials and Methods CEST MRI experiments were conducted on an egg white phantom and on prospectively enrolled brain tumor patients with T1 values modulated by gadolinium (Gd). QUASS algorithm was employed to reconstruct steady-state Z spectra. Conventional T1-uncorrected CEST effect was quantified with a multipool Lorentzian function from QUASS Z spectra. The non-QUASS AREX and QUASS-based AREX with T1 correction were calculated from the inverse of non-QUASS and QUASS Z spectra, respectively. The student’s t-test and Bland-Altman plots were performed to assess the statistical difference and consistency between pre- and post-Gd measurements. Results In the phantom study, vials with different T1 values showed conspicuous discrepancy on the conventional uncorrected APT and non-QUASS AREX maps, but comparable contrast on the QUASS-based AREX map. In the human study, 13 patients were enrolled. The contralateral normal-app...