Is pocket-size ultrasound a reliable tool for bowel investigation? A study on its feasibility, reproducibility and diagnostic accuracy

Background: Intestinal ultrasound (IUS) examination is a first-line non-invasive imaging procedure for patients with suspicion of bowel diseases. Aim: To assess the feasibility, reproducibility and diagnostic accuracy of a pocket-size ultrasound device (PUD) in identifying the presence of intestinal alterations in patients consecutively recruited to undergo IUS examination. Methods: 200 consecutive patients (57% female, 48.8 years) underwent both PUD (two independent investigators) and IUS examination on the same day. Nine ultrasonographic signs were systematically searched for. PUD inter-observer reproducibility was assessed by kappa statistic and ICC. The diagnostic accuracy of PUD as compared to IUS results was assessed by calculating sensitivity, specificity and corresponding positive and negative likelihood ratios. Results: PUD and IUS examinations were successful in 100% of the patients. PUD reproducibility was good/excellent at evidencing the presence (ICC 0.84) and length (ICC 0.85) of an intestinal tract with thickened wall and abdominal free fluid (ICC 0.87). The diagnostic accuracy of PUD, compared to traditional IUS, was good with regard to the presence of bowel wall thickening (sensitivity 92%, specificity 95%), the length of the thickened bowel (sensitivity 94%, specificity 95%) and the presence of free fluid (sensitivity 81%, specificity 99%). Conclusions: PUD is a feasible, reproducible and accurate first-line screening tool for the assessment of the gastro-intestinal tract