Feasibility of and agreement between MR imaging and spectroscopic estimation of hepatic proton density fat fraction in children with known or suspected nonalcoholic fatty liver disease

Abstract

Purpose To assess feasibility of and agreement between magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) for estimating hepatic proton density fat fraction (PDFF) in children with known or suspected nonalcoholic fatty liver disease (NAFLD). Material and Methods Children were included in this study from two previous research studies in each of which three MRI and three MRS acquisitions were obtained. Sequence acceptability, and MRI- and MRS-estimated PDFF were evaluated. Agreement of MRI- with MRS-estimated hepatic PDFF with MRS was assessed by linear regression and Bland-Altman analysis. Age, sex, BMI Z-score, acquisition time, and artifact score effects on MRI- and MRS-estimated PDFF agreement were assessed by multiple linear regression. Results Eighty-six children (61 boys, 25 girls) were included in this study. Slope and intercept from regressing MRS PDFF on MRI PDFF were 0.969 and 1.591%, respectively, and the Bland-Altman bias and 95% limits of agreement were 1.17% ± 2.61%. MRI motion artifact score was higher in boys than girls (by 0.21, p = 0.021). Higher BMI Z-score was associated with lower agreement between MRS and MRI (p = 0.045). Conclusion Hepatic PDFF estimation by both MRI and MRS is feasible, and MRI- and MRS-estimated PDFF agree closely in children with known or suspected NAFLD.

3D Chemical Shift‐Encoded MRI for Volume and Composition Quantification of Abdominal Adipose Tissue During an Overfeeding Protocol in Healthy Volunteers

“…However, some studies provided a better correlation. It should be noted that the range of values was larger in these studies (0–40% than in the present study (0–12%). Especially, it is challenging to accurately estimate very low fat content in liver.…”

“…Recent studies demonstrated the feasibility of assessing the composition of fat based on multiple gradient echo imaging also named CSE‐MRI. Studies focusing on liver diseases have extensively compared the MRS and MRI methods for the quantification of the PDFF …”

Standardized Approach for ROI-Based Measurements of Proton Density Fat Fraction and R2* in the Liver

“…Despite the growing clinical and research interest in these techniques, a standardized approach for ROI-based measurements has not been established. As a result, recent studies conducted at different sites have used a wide range of ROI sizes (from 0.785 cm 2 to the whole liver), locations (left and right lobes; anterior, posterior, and lateral segments; Couinaud segments; whole liver), and number (one to nine ROIs) for measurements of liver PDFF and R2* [6, 8, 16, 21–25]. This lack of standardization introduces an additional element of variability across sites and studies, impacting the widespread dissemination of these techniques as reproducible and repeatable quantitative imaging biomarkers.…”

Avaliação da doença hepática gordurosa não alcoólica pelo uso da ressonância nuclear magnética em crianças e adolescentes obesos

“…Um exame que tem ganhado grande destaque na literatura nos últimos anos é a RNM por espectroscopia (MRS), que apesar de ter grande acurácia, é um exame demorado e de difícil execução, por este motivo, no presente estudo elegemos a RM por imagem, pois tem risco mínimo, é não invasiva, mais rápida e mais fácil de realizar do que a MRS. Os resultados da RNM são mais precisos do que o ultrassom, não utiliza radiação ionizante, e fornece cobertura espacial de todo o fígado. Apesar da literatura referir que os exames de RNM em crianças pode ser um desafio por causa da apnéia, limitando a capacidade ou tolerância deste exame, podendo resultar em artefato de movimento e/ou exigindo modificação nos parâmetros da RNM para reduzir o tempo de apnéia (ACHMAD et al, 2015), não encontramos no presente trabalho tal dificuldade. Verificamos que ressonância nuclear magnética por imagem é um exame factível de ser executado em crianças e adolescentes, podendo representar uma ferramenta diagnóstica eficaz e não invasiva de esteatose hepática nesta faixa etária.…”

“…É um método não-invasivo, considerado exato e preciso, no entanto é demorado, tecnicamente difícil, restrito em cobertura espacial e, atualmente, só está disponível em alguns centros (ACHMAD et al, 2015).…”