ABSTRACT
Introdução: A doença hepática gordurosa não alcoólica (DHGNA) é uma das causas mais comuns de hepatopatia. Devido ao grande risco de progressão para cronicidade, seu rastreamento se faz necessário. A Elastografia por Ressônancia Magnética (MRE) foi estabelecida em diversos estudos como uma técnica acurada para o diagnóstico de fibrose. Objetivos: Descrever a prevalência de esteatose e de fibrose hepática em pacientes com DHGNA submetidos à MRE; estimar o grau de fibrose, correlacionando com a escala METAVIR, e avaliar a fração de gordura por densidade de prótons (PDFF) e os fatores clínicos associados à esteatose e fibrose. Métodos: Estudo transversal, realizado mediante revisão de imagens de MRE, entre janeiro de 2017 e março de 2019, em um hospital da região sul do Brasil. Resultados: Dos 298 pacientes incluídos, a maioria dos pacientes apresentava esteatose leve (41,6%, n=124) ou ausente (30,9%, n=92), enquanto 15,1% (n=45) apresentava esteatose moderada e 12,4% (n=37), acentuada. A maioria dos pacientes (65,8%, n=181) apresentava rigidez hepática dentro da normalidade, 11,6% (n=32) inflamação crônica, 7,6% (n=21) fibrose estágio 1-2, 3,6% (n=10) fibrose estágio 2-3, 4,7% (n=13) fibrose estágio 3-4 e 6,5% (n=18) fibrose estágio 4 ou cirrose. Discussão: Os resultados encontrados nesta amostra reforçam os fatores de risco para o desenvolvimento de DHGNA previamente avaliados. Uma combinação de estratégias não invasivas, incluindo a MRE, poderá selecionar os pacientes com maior probabilidade de agravos. Conclusão: Nesse estudo, a maioria dos pacientes apresentou a forma leve ou ausência de esteatose e rigidez hepática dentro da normalidade. A MRE tem se mostrado uma técnica altamente acurada, não invasiva para estadiamento de fibrose hepática em pacientes com DHGNA, sem influência significativa da idade, sexo, adiposidade e grau de inflamação hepática.
Introduction: Non-alcoholic fatty liver disease (NAFLD) is one of the most common causes of liver disease. Due to the high risk of progression to chronicity, its tracking is necessary. Magnetic Resonance Elastography (MRE) has been established in several studies as an accurate technique for diagnosing fibrosis. Objectives: To describe the prevalence of steatosis and liver fibrosis in NAFLD patients undergoing MRE; estimate the degree of fibrosis, correlating with the METAVIR scale, and assess the proton density fat-fraction (PDFF). Methods: A cross-sectional study, performed by reviewing MRE images, between January 2017 and March 2019, in a hospital in southern Brazil. Results: Of the 298 patients included, most patients had mild (41.6%, n=124) or absent (30.9%, n=92) steatosis, while 15.1% (n=45) had moderate and 12.4% (n=37) marked steatosis. Most patients (65.8%, n=181) had liver stiffness within the normal range, 11.6% (n=32) chronic inflammation, 7.6% (n=21) stage 1-2 fibrosis, 3.6% (n=10) stage 2-3 fibrosis, 4.7% (n=13) stage 3-4 fibrosis, and 6.5% (n=18) stage 4 fibrosis or cirrhosis. Discussion: The results found in this sample reinforce the risk factors for the development of NAFLD previously evaluated. A combination of non-invasive strategies, including MRE, may select the patients with the greatest likelihood of harm. Conclusions: MRE has been shown to be a highly accurate, non-invasive technique for staging liver fibrosis in NAFLD patients, with no significant influence of age, sex, adiposity, and degree of liver inflammation.
ABSTRACT
OBJECTIVE. The aim of the present study was to compare the diagnostic accuracy of liver stiffness measurements (LSMs) obtained using MR elastography (MRE), transient elastography (TE), and 2D shear wave elastography (SWE) in patients with biopsy-proven nonalcoholic fatty liver disease (NAFLD). SUBJECTS AND METHODS. We prospectively enrolled 62 adult subjects (mean age [± SD], 50 ± 13 years; 58% women; body mass index [weight in kilograms divided by the square of height in meters], 35 ± 7). Two-dimensional SWE, MRE, and TE were performed at a mean of 105 ± 86 days after liver biopsy. The area under the ROC curve (AUROC) values and 95% CIs for the corresponding LSMs (expressed in kilopascals) were calculated, with significant fibrosis (Metavir liver fibrosis score, F2-F4) and advanced fibrosis (F3-F4) used as outcome measures. Pairwise comparisons of AUROC values were conducted using the DeLong test. Statistical significance was set at p < 0.05. RESULTS. For the 62 subjects, valid LSMs were obtained for 57 subjects with the use of 2D SWE, for 59 subjects with TE, for 59 subjects with MRE, and for 54 subjects with all three modalities combined. The AUROC values (95% CIs) of 2D SWE, TE, and MRE for the diagnosis of significant fibrosis were 0.80 (0.67-0.92), 0.77 (0.64-0.89), and 0.85 (0.74-0.95), respectively. The AUROC values (95% CIs) of 2D SWE, TE, and MRE for the diagnosis of advanced fibrosis were 0.89 (0.80-0.98), 0.86 (0.77-0.95), and 0.95 (0.89-1.00), respectively. Pairwise comparisons revealed similar diagnostic accuracy for significant fibrosis (2D SWE vs MRE, p = 0.431; 2D SWE vs TE, p = 0.317; and MRE vs TE, p = 0.052) and advanced fibrosis (2D SWE vs MRE, p = 0.348; 2D SWE vs TE, p = 0.293; and MRE vs TE, p = 0.059). CONCLUSION. For patients with biopsy-proven NAFLD, 2D SWE, MRE and TE exhibited comparable and very good to excellent diagnostic accuracy for advanced fibrosis and comparable but lower accuracy for significant fibrosis.
Subject(s)
Elasticity Imaging Techniques/methods , Liver Cirrhosis/diagnostic imaging , Non-alcoholic Fatty Liver Disease/diagnostic imaging , Adult , Aged , Cross-Sectional Studies , Female , Humans , Liver Cirrhosis/complications , Magnetic Resonance Imaging , Male , Middle Aged , Non-alcoholic Fatty Liver Disease/complications , Prospective Studies , Reproducibility of ResultsABSTRACT
OBJECTIVE: To assess liver disease progression using paired magnetic resonance imaging (MRI) measurements of liver fat fraction (FF) and stiffness. STUDY DESIGN: Retrospective cohort study including patients with nonalcoholic fatty liver disease who had undergone repeat MRI studies. Descriptive statistics were used, as well as Pearson or Spearman correlation when appropriate. Mixed model analyses were used to determine relationships between liver FF/stiffness and predictor variables. RESULTS: Sixty-five patients (80% non-Hispanic, mean age 14 ± 3 years) were included. Time from first to last MRI was 27 ± 14 months. Over time, body mass index z score remained stable, and there were no significant differences in mean serum aminotransferases, insulin, glucose, triglycerides, low-density lipoprotein, and high-density lipoprotein (HDL) levels. However, the proportion of patients with alanine aminotransferase (ALT) < 50 U/L increased. MRI FF and stiffness decreased in 29% and 20% of patients, respectively, and increased in 25% and 22% of patients, respectively. There was a weak positive correlation between FF change and ALT change (r = 0.41, P = .053) and a moderate negative correlation between change in FF and change in serum HDL levels (r = -0.58, P = .004). After adjusting for HDL, increase in serum insulin was the only variable predictive of increase in FF (P = .061). There was no correlation between change in liver stiffness and change in ALT (r = .02, P = .910). CONCLUSIONS: MRI-determined hepatic FF and stiffness improved in a minority of patients overtime. ALT levels were not reflective of the change in FF or stiffness. MRI-based imaging is complementary in the assessment of NAFLD progression.