Jiang Yuanqiu, Yin Peiyuan, Wang Yishuang, Chen Meining, Yin Longlin
Department of Radiology, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.
Institute of Radiation Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.
Quant Imaging Med Surg. 2025 May 1;15(5):4400-4413. doi: 10.21037/qims-24-1786. Epub 2025 Apr 28.
With the increasing need for accurate liver disease diagnostics, non-invasive imaging techniques with rapid and precise quantitative measurements need to be established. This study introduced and validated the application of simultaneous multi-relaxation-time imaging (TXI) for the quantitative assessment of liver tissue by simultaneously acquiring proton density fat fraction (PDFF), lateral relaxation rate (R2*), and longitudinal relaxation time (T1) maps. It aimed to compare the accuracy and consistency of TXI with established quantitative magnetic resonance imaging (MRI) techniques, such as three-dimensional variable flip angle (VFA) T1 mapping, and multi-point quantitative Dixon (qDixon), in healthy volunteers and patients diagnosed with non-alcoholic fatty liver disease (NAFLD).
A prospective cohort of 35 healthy volunteers (mean age: 52±13 years, 21 women) and nine NAFLD patients (mean age: 48±13 years, 6 women) underwent liver MRI using TXI, VFA T1 mapping, and qDixon sequences. Intraclass correlation coefficients (ICCs) and Bland-Altman plots were used to assess inter-observer agreement and measurement consistency. Paired -tests and Pearson correlation coefficients were used to compare the TXI measurements with those from conventional MRI techniques. Differences between the healthy volunteers and NAFLD patients were evaluated using the independent sample -test.
The ICCs for the TXI-derived T1, R2*, and PDFF in healthy volunteers were 0.985 [95% confidence interval (CI): 0.971-0.993], 0.999 (95% CI: 0.998-1.000), and 0.995 (95% CI: 0.990-0.997), respectively, indicating excellent agreement. The regression analysis revealed strong correlations between the TXI and reference MRI measurements for the T1 (R=0.895), R2* (R=0.984), and PDFF (R=0.894) values with no significant differences (P=0.713, 0.090, and 0.072, respectively). Statistically significant differences were observed in the R2* (P=0.045) and PDFF (P<0.001) values between the NAFLD patients and healthy volunteers, but no significant difference was observed in the T1 values (P=0.965). Multiparametric imaging showed that TXI provides comprehensive liver tissue characterization, consistent with conventional MRI techniques.
TXI offers a rapid and reliable method for the simultaneous acquisition of T1, R2*, and PDFF maps, and has high consistency with established quantitative MRI techniques. This approach has significant potential for non-invasive liver tissue characterization in clinical settings, particularly in the diagnosis and monitoring of conditions such as NAFLD.
随着对肝脏疾病准确诊断的需求不断增加，需要建立能够进行快速、精确定量测量的非侵入性成像技术。本研究介绍并验证了同时多弛豫时间成像（TXI）在肝脏组织定量评估中的应用，该技术可同时获取质子密度脂肪分数（PDFF）、横向弛豫率（R2*）和纵向弛豫时间（T1）图谱。本研究旨在比较TXI与已确立的定量磁共振成像（MRI）技术（如三维可变翻转角（VFA）T1图谱和多点定量狄克逊（qDixon）技术）在健康志愿者和被诊断为非酒精性脂肪性肝病（NAFLD）患者中的准确性和一致性。
对35名健康志愿者（平均年龄：52±13岁，21名女性）和9名NAFLD患者（平均年龄：48±13岁，6名女性）的前瞻性队列进行肝脏MRI检查，采用TXI、VFA T1图谱和qDixon序列。组内相关系数（ICC）和布兰德-奥特曼图用于评估观察者间的一致性和测量的一致性。配对t检验和皮尔逊相关系数用于比较TXI测量值与传统MRI技术的测量值。使用独立样本t检验评估健康志愿者和NAFLD患者之间的差异。
健康志愿者中，TXI衍生的T1、R2和PDFF的ICC分别为0.985[95%置信区间（CI）：0.971-0.993]、0.999（95%CI：0.998-1.000）和0.995（95%CI：0.990-0.997），表明一致性极佳。回归分析显示，TXI与参考MRI测量的T1（R=0.895）、R2（R=)=0.984）和PDFF（R=0.894）值之间存在强相关性，且无显著差异（P分别为0.713、0.090和0.072）。在NAFLD患者和健康志愿者之间，R2*（P=0.045）和PDFF（P<0.001）值存在统计学显著差异，但T1值无显著差异（P=0.965）。多参数成像显示，TXI能够提供全面的肝脏组织特征，与传统MRI技术一致。
TXI为同时获取T1、R2*和PDFF图谱提供了一种快速可靠的方法，并且与已确立的定量MRI技术具有高度一致性。这种方法在临床环境中对肝脏组织进行非侵入性特征描述具有巨大潜力，特别是在NAFLD等疾病的诊断和监测方面。
