Attenuation imaging based on ultrasound technology for assessment of hepatic steatosis: A comparison with magnetic resonance imaging‐determined proton density fat fraction

Abstract

Aim: A new method has recently been developed for diagnosing hepatic steatosis based on attenuation measurement using ultrasound. We investigated the ability of attenuation imaging (ATI) to detect steatosis that was identified by proton density fat fraction (PDFF) on magnetic resonance imaging (MRI) in patients with chronic liver disease. Methods: A total of 119 patients with chronic liver disease (non-B, non-C) were analyzed. The relationship between ATI values and steatosis grades determined by PDFF was evaluated. Additionally, the diagnostic ability of ATI was evaluated using receiver operating characteristic curve analysis, and the correlation between ATI values and PDFF values was determined. Results: The ATI values of steatosis grades 0, 1, 2, and 3 were 0.55, 0.61, 0.74, and 0.84 dB/cm/MHz, respectively (P<0.001). There was a statistically significant trend of higher ATI values with higher steatosis grades (P<0.001). The correlation coefficient (r) between PDFF values and ATI values was 0.70 (95% confidence interval [CI] 0.59-0.78; P<0.001), corresponding to a strong relationship. The diagnostic ability of ATI for steatosis grades ≥1, ≥2, and 3, as determined by PDFF, were 0.81 (95% CI 0.73-0.89), 0.87 (95% CI 0.79-0.96), and 0.94 (95% CI 0.89-0.98), respectively. The r between PDFF values and ATI values was 0.49 (95% CI 0.31-0.63; P<0.001) for patients with mild or no steatosis (grade ≤1), and 0.75 (95% CI 0.57-0.86; P<0.001) for obese patients (body mass index ≥25 kg/m 2). Conclusion: ATI values had an excellent diagnostic ability to detect hepatic steatosis.

Accuracy of the ultrasound attenuation coefficient for the evaluation of hepatic steatosis: a systematic review and meta-analysis of prospective studies

“…The remaining 22 articles were assessed for eligibility according to their full text, leading to 13 articles being finally included after the exclusion of nine articles. Nine of the included articles reported the diagnostic accuracy of AC for diagnosing both ≥ S1 and ≥ S2 [2,12,[24][25][26][27][28][29][30], two articles reported it only for ≥ S1 [14,15], and two reported it only for ≥ S2 [13,31].…”

“…The characteristics of the included studies are shown in Table 1. Eight studies were conducted in Asia [2,12,14,24,25,[28][29][30]. Nine studies performed AC measurements using a Cannon ultrasound scanner [2,15,[25][26][27][28][29][30][31].…”

“…Eight studies were conducted in Asia [2,12,14,24,25,[28][29][30]. Nine studies performed AC measurements using a Cannon ultrasound scanner [2,15,[25][26][27][28][29][30][31]. Nine studies used liver biopsy as a reference standard to quantify hepatic steatosis [12][13][14]24,25,[27][28][29]31], and seven performed liver biopsy and…”

“…ultrasound on the same day [12,14,24,25,[27][28][29]. Four studies used MRI with proton density fat fraction (PDFF) as the reference standard, with the mean/median interval between ultrasound and MRI ranging from 7 to 32 days [2,15,26,30]. The mean BMI was over 25 in eight studies [2,13,15,24,26,27,29,31] and over 30 in two [13,15] studies.…”

“…In the assessment of the risk of bias, one article that investigated accuracy of AC in biopsy-proven NAFLD cohort had an unclear risk in patient selection, as there was no details of the definition of significant alcohol consumption when excluding patients [13]. All articles had a unclear risk in index test domains because all used their own threshold of index test determined in each cohort rather than prespecified one [2,[12][13][14][15][24][25][26][27][28][29][30][31]. Two studies had an uncertain risk of bias in the reference standard domain because of the absence of information on whether the analysis was performed without knowledge of the results of the index test [27,30].…”