Twenty-one studies were included in the review (n=3,486 patients). Across all studies, the mean number of responses within the QUADAS assessment tool was 10 (range 7 to 13) for “Yes”, 1 (range 0 to 3) for “No” and 3 (range 0 to 6) for “unclear”.
For low-frequency grey-scale techniques, diagnostic sensitivity ranged from 29 to 86.3% and specificity ranged from 35.3 to 99% (eight studies, 14 data sets).
For high-frequency grey-scale techniques (liver surface), diagnostic sensitivity ranged from 12.5 to 87.5% and specificity ranged from 78 to 95% (eight studies).
For Doppler techniques, sensitivity ranged from 31.4 to 94% and specificity ranged from 39 to 100% (six studies, 19 data sets).
For scoring systems, sensitivity and specificity both ranged from 68 to 100% (four studies, five data sets).
Studies that reported blinded interpretation of reference standard appeared to show greater diagnostic accuracy (ROC plot) than those where blinding was uncertain.