Reply

Abstract

Potential conflict of interest: Nothing to report. Reply: We thank Dr. Manatsathit for his insightful observations regarding the utility of magnetic resonance elastography (MRE) and acoustic radiation force impulse (ARFI) for noninvasively diagnosing fibrosis in nonalcoholic fatty liver disease (NAFLD) patients. MRE has been shown to be highly accurate for diagnosing fibrosis,1 and this study shows that MRE is superior to ARFI for fibrosis diagnosis. We would like to note that NAFLD fibrosis alone, without progression to advanced fibrosis, portends increased mortality and liver transplantation2 and that patients with hepatic steatosis alone may be genetically more susceptible to developing fibrosis.3 Therefore, early, noninvasive fibrosis diagnosis in high‐risk NAFLD patients is critical for the management of NAFLD and its complications, and MRE is more effective than ARFI for this purpose. Future studies are needed to compare MRE against other imaging techniques and clinical prediction rules to devise accurate, cost‐effective diagnostic algorithms to identify NAFLD patients with high risk for disease progression. Additionally, in our study, MRE had significantly better area under the receiver operating characteristic curves than ARFI for diagnosing fibrosis in obese patients (0.850 to 0.729), and this difference remained robust (0.914 to 0.536) in patients with stage 2 obesity (body mass index 35.0‐39.9 kg/m2). Other studies have shown that ultrasound‐based imaging techniques similar to ARFI, including transient elastography, also lose their diagnostic accuracy in higher‐body habitus patients.4 Compared to ARFI, MRE can make detailed fibrosis assessments of a much larger area of the liver and is minimally affected by body habitus.1 Therefore, we believe MRE may be highly useful for diagnosing fibrosis in obese NAFLD patients. Future improvements in MRE, including three‐dimensional MRE, promise even more diagnostic accuracy than traditional MRE.5 We believe MRE offers significant diagnostic advantages over ARFI for diagnosing early stages of fibrosis, especially in obese patients. And given the strong association between NAFLD and obesity, MRE can be a highly valuable tool for fibrosis diagnosis in these patients.