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Comparison of native T1 mapping and acoustic radiation force impulse elastography for noninvasively assessing liver fibrosis: repeatability, reproducibility, and staging and monitoring the fibrosis process
Jinning Li1, Huanhuan Liu1, Caiyuan Zhang1, Shuyan Yang1, Yanshu Wang1, Weibo Chen2, Xin Li3, and Dengbin Wang1

1Department of Radiology, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China, 2Philips Healthcare, Shanghai, China, 3GE Healthcare, Shanghai, China

Synopsis

To investigate the performances of native T1 mapping for noninvasively assessing liver fibrosis, including repeatability, reproducibility, and staging and monitoring the process of fibrosis, and to compare them with those of acoustic radiation force impulse (ARFI) elastography. The results of our experimental study suggest that native T1 mapping may be a reliable, accurate, and noninvasive tool for assessing liver fibrosis. Compared with ARFI elastography, native T1 mapping is a more robust quantitative technique with similar performances for staging fibrosis. Furthermore, it has a higher accuracy for monitoring liver fibrosis, especially for detecting fibrosis regression.

Introduction

Native T1 mapping, also called pre-contrast T1 mapping, has been shown a promising potential for noninvasively assessing liver fibrosis by previous studies 1,2. Native T1 mapping is a quick sequence and could be acquired within one breath-holding. It is implemented without additional hardware, which is the limitation of magnetic resonance elastopraphy, and could examine more volumes of the liver tissues than ultrasound-based elastography. However, its reliability and accuracy still need to be evaluated and compared with currently widely used noninvasive methods−elastography. Thus, the aim of this study was to investigate the performances of native T1 mapping for noninvasively assessing liver fibrosis, including repeatability, reproducibility, and staging and monitoring the process of fibrosis, and to compare them with those of acoustic radiation force impulse (ARFI) elastography.

Methods

Eight healthy SD rats were performed native T1 mapping and ARFI elastography in the liver three times. Native T1 values and shear wave velocity (SWV) were measured. Intraclass correlation coefficient (ICC) and within-subject coefficient of variation (WsCV) were calculated to evaluate the repeatability and reproducibility of quantitative parameters. Fifty-two SD rats were used to induce different stages of liver fibrosis with carbon tetrachloride. METAVIR system (F0–F4) was used as standard reference. Mixed model analysis of variance and area under the receiver operating characteristic curve (AUC) were adopted to evaluate and compare the diagnostic performance of native T1 values and SWV for diagnosing significant liver fibrosis (≥F2) and cirrhosis (F4). Another 16 rats with liver fibrosis underwent both imaging examinations before (session 1) and after (session 2) the progression/regression of fibrosis to evaluate the values of quantitative parameters for detecting fibrosis progression/regression in the liver using by using Wilcoxon signed-rank test and AUC.

Results

Native T1 values and SWV shared a similarly good repeatability (ICC=0.95, WsCV=3.59–4.15%), while native T1 values (ICC=0.79, WsCV=4.53%) demonstrated a better reproducibility than SWV (ICC=0.64；WsCV=8.63%). As Fig. 1 displayed, with the advance of fibrosis stage, both the quantitative parameters increased significantly (P<0.001). Native T1 values showed a high accuracy for diagnosing significant liver fibrosis (≥F2, AUC=0.84) as well as liver cirrhosis (F4, AUC=0.84), similar with SWV (≥F2, AUC=0.81; F4, AUC=0.86 ). As shown in Fig. 2-3, both native T1 values and SWV increased significantly (P≤0.041) after the progression of liver fibrosis, while only native T1 values decreased significantly (P=0.002) after the regression of fibrosis. For monitoring liver fibrosis, native T1 values yielded a better accuracy for detecting fibrosis progression (AUC=0.75) and regression (AUC=0.99) than SWV (progression, AUC=0.7; regression, AUC=0.56).

Discussion and Conclusion

The results of our experimental study suggest that native T1 mapping may be a reliable, accurate, and noninvasive tool for assessing liver fibrosis. Compared with ARFI elastography, native T1 mapping is a more robust quantitative technique with similar performances for staging fibrosis. Furthermore, it has a higher accuracy for monitoring liver fibrosis, especially for detecting fibrosis regression.

Acknowledgements

No acknowledgement found.

References

1. Banerjee R, Pavlides M, Tunnicliffe EM, et al. Multiparametric magnetic resonance for the non-invasive diagnosis of liver disease. J Hepatol.2014;60(1):69-77.

2. Pavlides M, Banerjee R, Sellwood J, et al. Multiparametric magnetic resonance imaging predicts clinical outcomes in patients with chronic liver disease. J Hepatol.2016;64(2):308-315.

Figures

Fig.1 The color-coded native T1 maps and acoustic radiation force impulse (ARFI) images in the liver at F0–F4 stages. Both native T1 values (from blue gradually to green and then to red) and SWV increased with the advance of fibrosis stage.

Fig.2 The color-coded native T1 maps and acoustic radiation force impulse (ARFI) images in the fibrosis progression/regression group. The images vividly depicted that both native T1 values and SWV increased after the progression of liver fibrosis and decreased after the regression of fibrosis.

Fig.3 The box plots of native T1 values and shear wave velocity (SWV) in the progression and regression group of liver fibrosis. Both quantitative parameters increased significantly after the progression of liver fibrosis (P ≤ 0.041), however, only native T1 values decreased significantly after the regression of fibrosis (P = 0.002). * P < 0.05, ** P < 0.01.

Proc. Intl. Soc. Mag. Reson. Med. 27 (2019)
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