Reproducibility and diagnostic accuracy of pocket-sized ultrasound devices in ruling out compensated cirrhosis of mixed etiology

Abstract

Objective: Fibrosis is the key prognostic factor in chronic liver disease patients. Liver surface nodularity (LSN) is the ultrasonographic sign with the highest accuracy to detect advanced liver fibrosis. The use of pocket-sized ultrasound devices (PUDs) has been assessed in several clinical settings but never as regards chronic liver disease (CLD) severity. Our study aimed at evaluating the feasibility, reproducibility, and diagnostic accuracy of PUD in LSN identification.

Methods: We enrolled all the consecutive adults referred for percutaneous liver biopsy. Two independent operators evaluated LSN by PUD; one sonographer used standard ultrasound (US). Transient elastography (TE) and liver biopsy were performed on all the patients. PUD reproducibility was evaluated by Cohen's k statistic. PUD, standard US, and TE results were compared with histology staging.

Results: A total of 104 consecutive patients (aged 54 ± 14 years) with mixed-etiology CLD were studied. Assessment by PUD was feasible in all the patients and showed very good inter-observer agreement with Cohen's k = 0.87 (95% CI 0.72-0.95). The diagnostic accuracy estimates for PUD in diagnosing compensated cirrhosis (F = 4) were 87.5% sensitivity, 76.8% specificity, positive likelihood ratio (LR) 3.78, and negative likelihood ratio (LR-) 0.16, while those for standard US and TE (> 12.5 kPa) were, respectively, 87.5% sensitivity, 72.6% specificity, LR+ 3.2, and LR- 0.17, and 87.5% sensitivity, 90.5% specificity, LR + 9.2, and LR- 0.13.

Conclusions: PUD reproducibility in assessing LSN was excellent even with operators of different experience. PUD performed very well in excluding advanced CLD. PUD can be used as a first-line tool for screening patients to undergo more invasive techniques, thus shortening the time for clinical decision-making.

Key points: • PUD is highly reproducible in assessing the sign of liver surface nodularity. • PUD showed high diagnostic accuracy in excluding the presence of advanced chronic liver disease. • PUD can be used as a first-line tool for screening patients with CLD who should undergo more invasive techniques.

Keywords: Liver cirrhosis; Liver diseases; Point-of-care systems; Ultrasonography.