Diagnostic Accuracy of a Portable, Handheld Point-of-Care Ultrasound Device vs a Traditional Cart-Based Model
Phase: NA
Conditions: Image, Body
Sponsor: Temple University

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Diagnostic Accuracy of a Handheld Ultrasound vs a 
Cart-Based Model: A Randomized Clinical Trial 
 
NCT05196776 
 
2 September 2023 
 
 
 
 
 
 
 

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Study Protocol 
Study investigators utilized permuted-block randomization with an allocation ratio of 1:1. 
Allocation concealment included sequentially numbered, opaque, sealed envelopes. Upon 
enrollment, blinded study investigators selected an envelope containing study materials and pre-
randomized selection into the handheld device (HH) or cart-based model (CB) using Research 
Randomizer (Version 4.0).26 Patients, who required a cardiac, lung, renal, aorta, or biliary 
POCUS, were randomized to a portable device, the Butterfly iQ (Guilford, CT) transducer 
connected to a 5th generation Apple iPad Mini (Cupertino, CA), or to a cart-based model, the GE 
Venue Go or GE Logiq E (Wauwatosa, WI). A PGY 1-3 emergency medicine (EM) resident 
performed each POCUS. An EP, credentialed in the core American College of Emergency 
Physicians POCUS applications, reviewed each study concurrently. Residents completed all 
POCUS scans prior to advanced imaging. 
A cardiologist-interpreted echocardiogram, performed within 24 hours of presentation to 
the emergency department, served as the reference standard for cardiac images. For biliary tract 
images, the reference standard was a radiology-interpreted ultrasound, performed during the ED 
visit. For lung, renal and aortic scans, the reference standard was computed tomography images 
(when available and performed during the ED visit), or POCUS quality assurance review by two 
ultrasound fellowship trained physicians (when no CT was available).” If there was 
disagreement, a third ultrasound fellowship trained physician provided an interpretation. The 
cardiologist, radiologist, and EPs were blinded to POCUS reads.  
 
Prior to starting their internship, our emergency medicine residents participate in an 
introductory five-hour introduction to POCUS course taught by our emergency ultrasound 
faculty. Additionally, each resident completes a three-week emergency ultrasound rotation 

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during their internship in accordance with Accreditation Council for Graduate Medical 
Education (ACGME) and ACEP guidelines.24,27 No additional training was provided to the 
residents prior to their study participation. Nonetheless, each participant completed more than 25 
of each scan prior to participating in the study to achieve competency per ACEP and AGME 
guidelines.24,27 
Measurements  
Prior to study commencement, study investigators defined the following diagnostic 
endpoints: ejection fraction (good >50%, moderate 30-50%, poor <30%) and the presence or 
absence of the following: gallstones, hydronephrosis (mild, moderate, or severe), B-lines (>3 in a 
single lung field), and abdominal aortic aneurysm (>3cm). 
Using the electronic medical record, Epic (Verona, WI), study investigators performed 
chart abstraction on all patients to obtain results of cardiology-interpreted echocardiograms and 
radiology-interpreted ultrasound and computed tomography studies.  
The primary endpoint was diagnostic accuracy of each imaging modality compared to the 
aforementioned gold standards. The secondary endpoint of image quality was assessed by three 
ultrasound fellowship-trained physicians using a previously validated Likert scale assessing 
image quality.28 A score of 1 indicated unable to interpret and a score of 7 specified superior 
imaging quality. 
Statistical Analysis 
Given the lack of pre-existing data comparing the modalities, investigators hypothesized 
that the cart-based model would have a 90% diagnostic accuracy versus 70% for the handheld 
device. We postulated that the HH would be inferior given the smaller screen size, novel 
technology to generate sonographic images, and limited provider experience with the device. To 

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detect a 20% difference, the sample size calculation of 98, with 49 patients randomized to each 
arm, was based on a power of 80% with an alpha of 0.05. We report continuous and categorical 
data as medians with interquartile ranges (IQR) or proportions with 95% confidence intervals 
(CIs) and utilized standard 2x2 tables to calculate test characteristics with 95% confidence 
intervals (CIs). Intraclass correlation coefficient (ICC) assessed inter-rater reliability between 
blinded expert reviewers, and the t-test compared median Likert scores. All analyses were 
performed using MedCalc (Version 19.1.6).