Performance of the Attenuation Imaging Technology in the Detection of Liver Steatosis

Abstract

Objectives The main aim was to assess the performance and cutoff value for the detection of liver steatosis (grade S > 0) with the Attenuation Imaging–Penetration (ATI‐Pen) algorithm available on the Aplio i‐series ultrasound systems (Canon Medical Systems, Otawara, Japan). The magnetic resonance imaging–derived proton density fat fraction (MRI‐PDFF) was used as the reference standard. Secondary aims were to compare the results to those obtained with the previous ATI algorithm (Attenuation Imaging–General [ATI‐Gen]) and with the controlled attenuation parameter (CAP) and to generate a regression equation between ATI‐Pen and ATI‐Gen values. Methods Consecutive adult patients potentially at risk of liver steatosis were prospectively enrolled. Each patient underwent ultrasound quantification of liver steatosis with ATI‐Pen and ATI‐Gen and a CAP assessment with the FibroScan system (Echosens, Paris, France). The MRI‐PDFF evaluation was performed within a week. The correlations between ATI‐Pen, ATI‐Gen, the CAP, and the MRI‐PDFF were analyzed with the Pearson rank correlation coefficient. The diagnostic performance of ATI‐Pen, ATI‐Gen, and the CAP was assessed with receiver operating characteristic curves and an area under the receiver operating characteristic curve (AUROC) analysis. Results Seventy‐two individuals (31 male and 41 female) were enrolled. Correlation coefficients of ATI‐Pen, ATI‐Gen, and the CAP with the MRI‐PDFF were 0.78, 0.83, and 0.58, respectively. The AUROCs of ATI‐Pen, ATI‐Gen, and the CAP for detecting steatosis (S > 0) were 0.90 (95% confidence interval, 0.81–0.96), 0.92 (0.82–0.98), and 0.85 (0.74–0.92), and the cutoffs were greater than 0.69 dB/cm/MHz, greater than 0.62 dB/cm/MHz, and greater than 273 dB/m. The regression equation between ATI‐Pen and ATI‐Gen was ATI‐Pen = 0.88 ATI‐Gen + 0.13. Conclusions Attenuation Imaging is a reliable tool for detecting liver steatosis, showing an excellent correlation with the MRI‐PDFF and high performance with AUROCs of 0.90 or higher.

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].…”

“…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].…”

“…B-mode ultrasound-guided measurement allows the echo signal transmitted by the A c c e p t e d A r t i c l e probe to be delivered to the liver more directly and precisely, which may result in more reliable and accurate measurement. Given this advantage of AC over CAP, several studies reported the diagnostic performance of AC, but the reported results are limited by small study populations (< 100) [2,14,15], and there are conflicting results as to whether or not AC has better diagnostic performance than CAP [14,15].…”