Validation and feasibility of liver T1 mapping using free breathing MOLLI sequence in children and young adults

Yeon Jin Cho,Woo Sun Kim,Munyoung Paek,Young Hun Choi,Seul Bi Lee,Seungtae Woo,Seunghyun Lee,Jung-Eun Cheon

doi:10.1038/s41598-020-74717-2

Yeon Jin Cho, Woo Sun Kim + Show 6 more

Open Access

https://doi.org/10.1038/s41598-020-74717-2

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Abstract

We investigated the feasibility of free-breathing modified Look-Locker inversion recovery (MOLLI) sequence for measuring hepatic T1 values in children and young adults. To investigate the accuracy and the reproducibility of the T1 maps, a phantom study was performed with 12 different gadoterate meglumine concentrations and the T1 relaxation times of phantoms measured with the MOLLI sequence were compared against those measured with three different sequences: spin-echo inversion recovery, variable flip angle (VFA), and VFA with B1 correction. To evaluate the feasibility of free-breathing MOLLI sequence, hepatic T1 relaxation times obtained by free-breathing and breath-hold technique in twenty patients were compared. The phantom study revealed the excellent accuracy and reproducibility of MOLLI. In twenty patients, the mean value of hepatic T1 values obtained by free-breathing (606.7 ± 64.5 ms) and breath-hold (609.8 ± 64.0 ms) techniques showed no significant difference (p > 0.05). The Bland–Altman plot between the free-breathing and breath-hold revealed that the mean difference of T1 values was − 3.0 ms (− 0.5%). Therefore, T1 relaxation times obtained by MOLLI were comparable to the values obtained using the standard inversion recovery method. The hepatic T1 relaxation times measured by MOLLI technique with free-breathing were comparable to those obtained with breath-hold in children and young adults.

Highlights

The increasing prevalence of chronic liver disease in children has a significant impact on public h ealth[1]
The T1 relaxation time obtained by variable flip angle (VFA) with B1 correction and modified Look-Locker inversion recovery (MOLLI) methods showed an excellent correlation with the SE-inversion recovery (IR) method (PCC = 0.999, 95% CI 0.996–1.000 for VFA vs. spin-echo inversion recovery (SE-IR); PCC = 0.999, 95% CI 0.998–1.000 for VFA with B1 correction vs. SE-IR; PCC = 0.999, 95% CI 0.997–1.000 for MOLLI vs. SE-IR; p < 0.001) (Fig. 2)
The VFA, VFA with B1 correction and MOLLI sequences showed good correlation with the reference standard of the T1 relaxation times measured by SE-IR19

Summary

Introduction

The increasing prevalence of chronic liver disease in children has a significant impact on public h ealth[1]. Various non-invasive and clinically-accepted methods for evaluating liver fibrosis have been developed These include fibrosis scoring system using laboratory results, transient elastography, acoustic radiation force impulse imaging, magnetic resonance elastography, and T1 mapping using M RI4. The most accurate method of measuring T1 relaxation time is through the acquisition of a series of inversion recovery pulse images with different inversion times This technique is clinically impractical, especially in children, because it requires a relatively long scan time and multiple breath-holds[12]. The purpose of our study is to evaluate the usefulness of MOLLI sequence for measuring hepatic T1 values in comparison to the standard spin-echo inversion recovery (SE-IR) sequence and variable flip angle (VFA) sequence. We aim to assess the feasibility of a free-breathing MOLLI sequence in children and young adults[8,19,20,21]

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