Diagnostic comparison of vibration-controlled transient elastography and MRI techniques in overweight and obese patients with NAFLD

www.nature.com/scientificreports OPEN Diagnostic comparison of vibration‑controlled transient elastography and MRI techniques in overweight and obese patients with NAFLD Asako Nogami 1, Masato Yoneda 1*, Michihiro Iwaki 1, Takashi Kobayashi 1, Takaomi Kessoku 1,2, Yasushi Honda 1, Yuji Ogawa 1,3, Kento Imajo 1,4, Takuma Higurashi 1, Kunihiro Hosono 1, Hiroyuki Kirikoshi 5, Satoru Saito 1 & Atsushi Nakajima 1 Non-invasive imaging techniques have greatly advanced the assessment of liver fibrosis and steatosis but are not fully evaluated in overweight patients. We evaluated the diagnostic performance of vibration-controlled transient elastography (VCTE) and magnetic resonance elastography (MRE) to assess fibrosis and controlled attenuation parameter (CAP) and MR imaging (MRI)-proton density fat fraction (MRI-PDFF) to assess steatosis in overweight and obese patients with non-alcoholic fatty liver disease (NAFLD). We included 163 biopsy-proven patients with NAFLD who underwent VCTE, MRE/MRI-PDFF, and liver biopsy (years 2014–2020) who were classified according to their body mass index (BMI) as normal (BMI < 25 kg/m2, n = 38), overweight (25 ≤ BMI < 30 kg/m2, n = 68), and obese (BMI ≥ 30 kg/m2, n = 57). VCTE and MRE detected fibrosis of stages ≥ 2, ≥ 3, and 4 with an area under the receiver operating curve (AUROC) of 0.83–0.94 (VCTE) and 0.85–0.95 (MRE) in all groups, without considerable differences. MRI-PDFF detected steatosis of grades ≥ 2 and 3 with high AUROC in all groups (0.81–1.00). CAP’s diagnostic ability (0.63–0.95) was lower than that of MRI-PDFF and decreased with increasing BMI compared to MRI-PDFF. VCTE and MRE similarly accurately assess fibrosis, although MRI-PDFF is more accurate than CAP in detecting steatosis in overweight and obese patients with NAFLD. The number of patients diagnosed with non-alcoholic fatty liver disease (NAFLD) is rising worldwide1. Obesity is a key risk factor for NAFLD development, and it is estimated that 90% of obese people suffer from N AFLD2. Obesity increases the risk of NAFLD by almost fi vefold3 and accelerates its progression to advanced fibrosis, cirrhosis, and non-alcoholic steatohepatitis (NASH)4. Liver biopsy is currently the gold standard method for diagnosing liver fibrosis, steatosis, inflammation, and hepatocyte ballooning in NAFLD. However, there are limitations to consider when performing liver biopsy, including the invasiveness of the procedure, and the risk of sampling errors. Therefore, elastography was developed as an alternative, non-invasive technique. The accurate assessment of liver fibrosis is essential for patients with NAFLD as this is the most important pathological determinant of p rognosis5–7. The estimated prevalence of NAFLD among Asians is 27.4% (95% confidence interval CI 23.3–31.9%)8, and it is reported that individuals with overweight and obese have increased risk of NAFLD and 50.7% of them has NAFLD9. It remains unclear whether elastography has sufficient diagnostic ability for overweight and obese patients. In the evaluation of NAFLD, magnetic resonance imaging (MRI)-based techniques have been reported 1 Department of Gastroenterology and Hepatology, Yokohama City University Graduate School of Medicine, 3‑9 Fukuura, Kanazawaku, Yokohama 236‑0004, Japan. 2Department of Palliative Care, International University of Health and Welfare Narita Hospital, 852 Hatakeda Narita, Chiba 286‑8520, Japan. 3Department of Gastroenterology, National Hospital Organization Yokohama Medical Center, 3‑60‑2 Harajuku, Totsukaku, Yokohama 245‑8575, Japan. 4Department of Gastroenterology and Endoscopy, Shinyurigaoka General Hospital, 255 Furusawatsuko, Asoku, Kawasaki 215‑0026, Japan. 5Clinical Laboratory Department, Yokohama City University Hospital, 3‑9 Fukuura, Kanazawaku, Yokohama 236‑0004, Japan. *email: Scientific Reports | (2022) 12:21925 | https://doi.org/10.1038/s41598-022-25843-6 1 Vol.:(0123456789) www.nature.com/scientificreports/ to have a better diagnostic performance than vibration-controlled transient elastography (VCTE)10,11; when compared to VCTE, MRI-based techniques are more expensive and time consuming to implement. Therefore, it is clinically useful to know the difference in diagnostic performance between these two techniques. In this study, we investigated the accuracy of VCTE and magnetic resonance elastography (MRE) to detect liver fibrosis and the accuracy of controlled attenuation parameter (CAP) measurements. Similarly, we performed and MRI-based proton density fat fraction (MRI-PDFF) to detect liver steatosis among patients with overweight and obese. Methods Study design. We conducted a cross-sectional retrospective study of patients with NAFLD who had undergone all three examinations (liver biopsy, VCTE and MRE) within 6 months between January 2014 and March 2020 at Yokohama City University Hospital. The study protocol complied with the ethical principles of the 1975 Declaration of Helsinki and was approved by the Ethics Committee of Yokohama City University Hospital (Yokohama, Japan; approval number B2104, April 28, 2021), and all patients provided written informed consent. The inclusion and exclusion criteria are described in Supplementary Online Resource 1. Definition of overweight and obese. According to the World Health Organization definition, obesity is defined as a body mass index (BMI) ≥ 30 kg/m2, and overweight is defined as a BMI > 25 and < 30 kg/m212. Notably, Asians have high prevalence of type 2 diabetes and cardiovascular risk factors, even among normal weight populations (those with a BMI > 25 kg/m2)13. In 2004, the World Health Organization Western Pacific Regional Office established a different definition of obesity for Asians, where the BMI was categorized as “underweight” (< 18.4 kg/m2), “normal” (≥ 18.5–22.9 kg/m2), “overweight at risk (overweight)” (≥ 23.0–24.9 kg/m2), “obese I” (≥ 25.0–29.9 kg/m2), and “obese II” (≥ 30.0 kg/m2)13. In our country, the Japanese Society for the Study of Obesity defines obesity as a BMI of 25 > kg/m2 or a bove14. In the current study, we used international standards to define BMI < 25 as “normal,” BMI > 25 and < 30 kg/m2 as “overweight,” and BMI ≥ 30 kg/m2 as “obese.” Histological findings. Liver biopsy was performed in all participants. The procedure and methods are described in Supplementary Online Resource 2. Grading and staging were based on the NASH clinical network criteria, as previously reported. Steatosis affecting < 5%, 5%–33%, 33–66% and > 66% of hepatocytes was classified as grade 0, 1, 2 and 3, respectively. Lobular inflammation was graded according to the number of inflammatory foci per field of view at a magnification of 200× , with 0, < 2, 2 − 4, and > 4 foci per field classified as grades 0, 1, 2, and 3, respectively. Hepatocellular ballooning involving no, few, and many cells was classified as grade 0, 1, and 2, respectively15. Vibration controlled transient elastography. VCTE data were determined utili (...truncated)