Noninvasive Differential Diagnosis of Liver Iron Contents in Nonalcoholic Steatohepatitis and Simple Steatosis Using Multiecho Dixon Magnetic Resonance Imaging

Artificial Intelligence in NAFLD: Will Liver Biopsy Still Be Necessary in the Future?

As the advanced form of nonalcoholic fatty liver disease (NAFLD), nonalcoholic steatohepatitis (NASH) will significantly increase the risks of liver fibrosis, cirrhosis, and HCC. However, there is no non-invasive method to distinguish NASH from NAFLD so far. Additionally, liver biopsy remains the gold standard to diagnose NASH, which is not appropriate for routine screening. Recently, artificial intelligence (AI) is under rapid development in many aspects of medicine. Additionally, the application of AI in clinical information may have the potential to diagnose NASH non-invasively. This review summarizes the latest research using AI, specifically machine learning, to facilitate the diagnosis, prognosis, and monitoring of NAFLD. Additionally, according to our prior results, this work proposes future development in this area.

Magnetic resonance spectroscopy for quantification of liver iron deposition in hereditary hemochromatosis of a Chinese family: Four case reports

RATIONALE

Hereditary hemochromatosis (HH) is a major cause of liver iron overload. The gold standard for the diagnosis of liver iron overload is the histopathological analysis of a liver sample collected by biopsy. The biopsy procedure is both invasive and painful and carries some risks of complications. The multi-echo single-voxel magnetic resonance spectroscopy (HISTO) technique can be used for noninvasive, quantitative assessment of liver iron overload.

PATIENT CONCERNS

We report 4 Chinese Han men, who were relatives. Patient A was admitted with diabetes and presented with thrombocytopenia and skin hyperpigmentation. The other patients had no specific clinical presentation.

DIAGNOSES

Patient A was suspected of having iron in the liver on routine magnetic resonance imaging, therefore, further HISTO, laboratory testing, and liver biopsy were performed, which confirmed iron metabolic abnormalities. Furthermore, we identified hepatic iron deposition using HISTO and laboratory testing of his son and 2 brothers. Combined with symptoms, auxiliary examinations, and liver biopsy, HH was considered.

INTERVENTIONS

As the 4 patients had no other discomfort other than patient A who had diabetes, patient A was placed on therapy comprising the insulin pump, acarbose, and platelet booster capsule.

OUTCOMES

After treatment, the diabetic symptoms of patient A improved. The patient and his relatives were regularly followed-up for HH.

LESSONS

HH should be considered when hepatic iron deposition is suspected by routine magnetic resonance, as the HISTO sequence can quantitate liver iron deposition and leads to a promising diagnosis. HISTO is of great value in familial cases, especially in young patients requiring long-term follow-up.

Water Specific MRI T1 Mapping for Evaluating Liver Inflammation Activity Grades in Rats With Methionine-Choline-Deficient Diet-Induced Nonalcoholic Fatty Liver Disease

BACKGROUND

Early detection and grading of liver inflammation are important for the management of nonalcoholic fatty liver disease (NAFLD) patients. There is still lack of a noninvasive way for the inflammation characterization in NAFLD.

PURPOSE

To assess liver inflammation grades by water specific T1 (wT1) in a rat model.

STUDY TYPE

Prospective.

ANIMAL MODEL

A total of 65 male rats with methionine-choline-deficient diet-induced NAFLD and 15 male normal rats as control.

FIELD STRENGTH/SEQUENCE

A 3 T; multiecho variable flip angle gradient echo sequence.

ASSESSMENT

The wT1 and proton density fat fraction were quantified. Inflammation and fibrosis were assessed histologically with H&E and Sirius red stained slices according to the nonalcoholic steatohepatitis scoring system. Inflammation grade was scored with G0/G1/G2/G3 as none/mild/moderate/severe inflammation in NALFD rats. G0 + G1 and G2 + G3 were combined as none-to-mild grade (GL) and moderate-to-severe grade (GH) inflammation groups.

STATISTICAL TESTS

Analysis of variance (ANOVA), Mann-Whitney U test, Spearman's correlation, and receiver operating characteristic (ROC) analysis were performed. The areas under ROC (AUROC) was used for the diagnostic performance of wT1 in discriminating GH and GL. A P value < 0.01 was considered statistically significant.

RESULTS

Seventy-six rats were included in the analysis. The numbers in G0-G3 groups were 5, 16, 13, and 27. wT1 of G0-G3 was 568.55 ± 63.93 msec, 582.53 ± 62.98 msec, 521.21 ± 67.31 msec, and 508.79 ± 60.53 msec. A moderate but significant negative correlation between wT1 and histopathological inflammation grades was observed (r_s  = -0.42). The wT1 of GH (512.80 ± 62.22 msec) was significantly lower than GL (579.20 ± 61.89 msec). The AUROC of wT1 was 0.79, and the optimal cut-off of wT1 was 562.64 msec (sensitivity: 90%, specificity: 76%), for the discrimination of GL and GH.

DATA CONCLUSIONS

wT1 could differentiate none-to-mild inflammation from moderate-to-severe inflammation in the early stage of the NAFLD rat model.

EVIDENCE LEVEL

1 TECHNICAL EFFICACY: Stage 1.

Non-linear association of serum molybdenum and linear association of serum zinc with nonalcoholic fatty liver disease: Multiple-exposure and Mendelian randomization approach

The homeostasis imbalance of metals is closely associated with nonalcoholic fatty liver disease (NAFLD). A total of 1594 and 566 Chinese Han men were enrolled in cross-sectional and longitudinal analyses, respectively. We measured the serum concentrations of 22 metals by ICP-MS. The traditional and the LASSO regression methods were used to construct multiple-metals models, respectively. We performed Mendelian randomization (MR) analysis to confirm the causal relationship between NAFLD and metals using three NAFLD-related SNPs as instrumental variable. After adjustment in the six-metal model, only depressed molybdenum and elevated zinc were associated with a higher NAFLD risk, in both cross-sectional and longitudinal analyses. In the twelve-metal model, similar results were still observed. Moreover, dose-response relationships were non-linear for molybdenum and positively linear for zinc with NAFLD risk. In MR analysis, no causal associations were found from NAFLD to molybdenum and zinc. Our results support that serum molybdenum levels were non-linearly associated with NAFLD risk in Chinese men, whereas serum zinc levels showed a positively linear association. Moreover, MR analysis indicated the changes in serum molybdenum and zinc levels might be not caused by NAFLD, further confirmed our findings in cross-sectional and longitudinal analyses.

Accuracy of proton magnetic resonance for diagnosing non-alcoholic steatohepatitis: a meta-analysis

Liver biopsy is the reference standard test to differentiate between non-alcoholic steatohepatitis (NASH) and simple steatosis (SS) in non-alcoholic fatty liver disease (NAFLD), but noninvasive diagnostics are warranted. The diagnostic accuracy in NASH using MR imaging modality have not yet been clearly identified. This study was assessed the accuracy of magnetic resonance imaging (MRI) method for diagnosing NASH. Data were extracted from research articles obtained after a literature search from multiple electronic databases. Random-effects meta-analyses were performed to obtain overall effect size of the area under the receiver operating characteristic(ROC) curve, sensitivity, specificity, likelihood ratios(LR), diagnostic odds ratio(DOR) of MRI method in detecting histopathologically-proven SS(or non-NASH) and NASH. Seven studies were analyzed 485 patients, which included 207 SS and 278 NASH. The pooled sensitivity was 87.4% (95% CI, 76.4–95.3) and specificity was 74.3% (95% CI, 62.4–84.6). Pooled positive LR was 2.59 (95% CI, 1.96–3.42) and negative LR was 0.17 (95% CI, 0.07–0.38). DOR was 21.57 (95% CI, 7.27–63.99). The area under the curve of summary ROC was 0.89. Our meta-analysis shows that the MRI-based diagnostic methods are valuable additions in detecting NASH.

Noninvasive evaluation of nonalcoholic fatty liver disease: Current evidence and practice

With the increasing number of individuals with diabetes and obesity, nonalcoholic fatty liver disease (NAFLD) is becoming increasingly prevalent, affecting one-quarter of adults worldwide. The spectrum of NAFLD ranges from simple steatosis or nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH). NAFLD, especially NASH, may progress to fibrosis, leading to cirrhosis and hepatocellular carcinoma. NAFLD can impose a severe economic burden, and patients with NAFLD-related terminal or deteriorative liver diseases have become one of the main groups receiving liver transplantation. The increasing prevalence of NAFLD and the severe outcomes of NASH make it necessary to use effective methods to identify NAFLD. Although recognized as the gold standard, biopsy is limited by its sampling bias, poor acceptability, and severe complications, such as mortality, bleeding, and pain. Therefore, noninvasive methods are urgently needed to avoid biopsy for diagnosing NAFLD. This review discusses the current noninvasive methods for assessing NAFLD, including steatosis, NASH, and NAFLD-related fibrosis, and explores the advantages and disadvantages of measurement tools. In addition, we analyze potential noninvasive biomarkers for tracking disease processes and monitoring treatment effects, and explore effective algorithms consisting of imaging and nonimaging biomarkers for diagnosing advanced fibrosis and reducing unnecessary biopsies in clinical practice.