Diagnostic Accuracy of a Handheld Ultrasound vs a Cart-based Model: A Randomized Clinical Trial

Abstract

Introduction: Numerous studies have demonstrated the accuracy of point-of-care ultrasound (POCUS). Portable, handheld devices have expanded the clinical scope of POCUS at a fraction of the cost of traditional, cart-based models. There is a paucity of data assessing the diagnostic accuracy of portable devices. Our objective in this study was to compare the diagnostic accuracy of a portable device with a cart-based model.

Methods: This was an institutional review board-approved, observational, prospective, randomized clinical trial (NCT05196776) of a convenience sample of adult patients who presented to a university-based health system. Patients who required a cardiac, lung, renal, aorta, or biliary POCUS were randomized to a portable device or to a cart-based model. We hypothesized that the cart-based model would have a 90% diagnostic accuracy vs 70% for the handheld device. To detect a 20% difference, the sample size was calculated to be 98, with 49 patients randomized to each arm. We used standard 2x2 tables to calculate test characteristics with 95% confidence intervals (CI).

Results: A total of 110 patients were enrolled, with 56 patients randomized to the cart-based model and 54 to the handheld device. The sensitivity, specificity, and diagnostic accuracy of the cart-based vs handheld were 77.8% (40-97.2) vs 92.9% (66.1-99.8), 91.5% (79.6-97.6) vs 92.3% (79.1-98.4%), and 89.3% (78.1-96) vs 92.5% (81.8-97.9), respectively.

Conclusion: The diagnostic accuracy of a portable, handheld device is similar to that of a cart-based model.

Image.

Handheld Butterfly iQ device and cart-based GE Venue Go model demonstrating parasternal long axis view.

Figure 1.

Patient flow chart. CB, cart-based ultrasound model; HH, handheld device; POCUS, point-of-care ultrasound; QA, quality assurance review; NCCT, non-contrast computed tomography of the abdomen and pelvis.