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. 2021 Aug 11;16(8):e0255919.
doi: 10.1371/journal.pone.0255919. eCollection 2021.

Testing telediagnostic right upper quadrant abdominal ultrasound in Peru: A new horizon in expanding access to imaging in rural and underserved areas

Thomas J Marini  1 , Daniel C Oppenheimer  1 , Timothy M Baran  1 , Deborah J Rubens  1 , Ann Dozier  2 , Brian Garra  3 , Miguel S Egoavil  4 , Rosemary A Quinn  1 , Jonah Kan  1 , Rafael L Ortega  1 , Yu T Zhao  1 , Lorena Tamayo  4 , Claudia Carlotto  4 , Benjamin Castaneda  5
Affiliations

Testing telediagnostic right upper quadrant abdominal ultrasound in Peru: A new horizon in expanding access to imaging in rural and underserved areas

Thomas J Marini et al. PLoS One. .

Abstract

Background: Hepatic and biliary diseases are prevalent worldwide, but the majority of people lack access to diagnostic medical imaging for their assessment. The liver and gallbladder are readily amenable to sonographic examination, and ultrasound is a portable, cost-effective imaging modality suitable for use in rural and underserved areas. However, the deployment of ultrasound in these settings is limited by the lack of experienced sonographers to perform the exam. In this study, we tested an asynchronous telediagnostic system for right upper quadrant abdominal ultrasound examination operated by individuals without prior ultrasound experience to facilitate deployment of ultrasound to rural and underserved areas.

Methods: The teleultrasound system utilized in this study employs volume sweep imaging and a telemedicine app installed on a tablet which connects to an ultrasound machine. Volume sweep imaging is an ultrasound technique in which an individual scans the target region utilizing preset ultrasound sweeps demarcated by easily recognized external body landmarks. The sweeps are saved as video clips for later interpretation by an experienced radiologist. Teleultrasound scans from a Peruvian clinic obtained by individuals without prior ultrasound experience were sent to the United States for remote interpretation and quality assessment. Standard of care comparison was made to a same-day ultrasound examination performed by a radiologist.

Results: Individuals without prior ultrasound experience scanned 144 subjects. Image quality was rated "poor" on 36.8% of exams, "acceptable" on 38.9% of exams, and "excellent" on 24.3% of exams. Among telemedicine exams of "acceptable" or "excellent" image quality (n = 91), greater than 80% of the liver and gallbladder were visualized in the majority of cases. In this group, there was 95% agreement between standard of care and teleultrasound on whether an exam was normal or abnormal, with a Cohen's kappa of 0.84 (95% CI 0.7-0.98, p <0.0001). Finally, among these teleultrasound exams of "acceptable" or "excellent" image quality, the sensitivity for cholelithiasis was 93% (95% CI 68.1%-99.8%), and the specificity was 97% (95% CI 89.5%-99.6%).

Conclusion: This asynchronous telediagnostic system allows individuals without prior ultrasound experience to effectively scan the liver, gallbladder, and right kidney with a high degree of agreement with standard of care ultrasound. This system can be deployed to improve access to diagnostic imaging in low-resource areas.

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Conflict of interest statement

The authors have read the journal’s policy and have the following competing interests: ME, LT, and CC were paid employees of Medical Innovation and Technology during the study period. Medical Innovation and Technology also provided funding for the logistical costs associated with data collection. BC is the founder of and has a financial stake in Medical Innovation and Technology. This company seeks to bring ultrasound to rural areas through telemedicine. The authors would like to declare the following marketed product associated with this research: “Medical for Ultrasound” or “Med4US." This does not alter our adherence to PLOS ONE policies on sharing data and materials. There are no other patents, products in development, or marketed products associated with this research to declare.

Figures

Fig 1
Fig 1. Overview of the RUQ telediagnostic ultrasound system.
Imaging information of the right upper abdominal quadrant is acquired by health personnel of any skill level and is sent through the tablet from the health center for remote imaging interpretation (blue arrows). A diagnostic report is returned to the health center for the health personnel and patient (green arrows).
Fig 2
Fig 2. Overview of the RUQ protocol.
The RUQ protocol involves 6 sweeps each beginning and ending with an arc of the probe that has not been illustrated for simplicity. An arc consists of a fan-like motion of the probe (shown in S1 File). The arcing of the probe allows maximal visualization. Steps a-c involve transverse sweeps of the probe in the supine position. Steps d and e are conducted in the left lateral decubitus position. Step f is performed in the standing position. The patient takes a deep breath during each step.
Fig 3
Fig 3. Normal RUQ VSI exam.
(a) Normal liver identified on transverse VSI scan. (b) Normal gallbladder (arrows) identified on sagittal VSI scan. Transverse (c) and sagittal (d) images of the kidney (arrows) with partial visualization of the liver (*). S2 File includes the cine clips of this exam.
Fig 4
Fig 4. Cholelithiasis.
Cholelithiasis with echogenic stone and posterior acoustic shadowing seen on standard of care (a) and VSI (b). Online Video 3 includes a sample cine clip of this study.
Fig 5
Fig 5. Gallbladder polyp.
Gallbladder polyp with faint comet tail artifact seen on standard of care (a) and VSI (b).
Fig 6
Fig 6. Diffuse hepatic steatosis.
Diffuse hepatic steatosis seen on standard of care imaging (a) and VSI (b). In both images there is significant increase in hepatic echogenicity.
See this image and copyright information in PMC

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