In this interview we speak with Brian G. Choi, MD, MBA, FACC about his recent research testing remote interpretation on a smartphone with dedicated medical imaging software in the Journal of the American Society of Echocardiography.1 Dr. Choi is the Assistant Professor of Medicine and Co-Director of Advanced Cardiac Imaging at The Richard B. & Lynne V. Cheney Cardiovascular Institute, George Washington University, in Washington, DC.
Describe your objectives for this study.
The objective of our study was to validate the interpretation of echocardiographic images on a dedicated smartphone app (mVisum onDemand version 1.0.0, mVisum, Inc., Camden, NJ) versus expert echocardiographic interpretation on a workstation.
What are some of the limits to current techniques in remote real-time echocardiogram interpretation?
Cost. Previously described systems have required dedicated satellite connections and custom wireless transmitters. In our research we describe a low-cost system that only requires reliable Internet access on the transmitting and receiving ends.
Security. Transmission over the public Internet as well as cell phone data networks may bring concerns over the security of sensitive health information. The system we used was fully HIPAA-compliant with data encryption and several authentication layers.
Access. Previously described systems required workstation-based interpretation, but real-time access requires that the interpreting physician be immediately available. A smartphone-based app means that the interpreting echocardiographer can be anywhere when he/she interprets the study, e.g., at home, at a restaurant, in line at the grocery store, etc.
Tell us more about this humanitarian mission in Honduras. How did it come about to use the mVisum technology during this mission?
The Cheney Cardiovascular Institute at GW supports an annual medical mission to a remote area of Honduras, where medical care is relatively inaccessible and ultrasound is unavailable. Chagas cardiomyopathy and rheumatic heart disease, diseases with severe consequences, are still endemic in rural Honduras, so the ability to perform diagnostic echocardiography would be highly useful in this setting. Our Institute had recently purchased a Vscan (GE Healthcare, Wauwatosa, WI) looking at potential research applications, but the value of using such a device, which is highly portable and battery-powered, was intuitively obvious for the medical mission setting, and we lent it to the mission team. However, for that trip, there was no expert echocardiographer/sonographer available to accompany the mission team. A general cardiology fellow was accompanying the team, and we felt that if she were able to send the images back to the US for remote expert overread, sending the Vscan with the mission would be useful. At the same time, I had been working with a company called mVisum to help them develop an echo app for the smartphone. When this mission trip came around, I thought the marriage of the Vscan with a smartphone-based echo reading app would be the most advanced way to remotely acquire images as well as remotely read them for the maximal convenience of the reader.
Describe the mVisum technology used in this study. How does it work? Describe the layout of the system.
Images are uploaded to the mVisum Platform Server, which may be accessed by the mVisum smartphone app. The app is authenticated by unique user name, password, and the smartphone’s unique device identification number (UDID), and all transactions are logged by the server.
Tell us more about the GE technology used in this study.
The GE Vscan is a handheld, highly portable ultrasound device — the size is similar to a large cell phone. The screen is 8.9 cm-diagonal, and the device has color flow Doppler capability. Notably, it lacks Spectral Doppler, M-mode and electrocardiographic leads, so it should not be viewed as a complete replacement to traditional echocardiography. However, the small size makes it highly portable, which has unique advantages. It may be brought to locations previously inaccessible, whether at the bedside of a critical patient in a crowded hospital room, or on a medical mission, as we used in our case. Its rapid boot-up time also has advantages for the “super-stat” evaluation.
Discuss the diagnostic accuracy differences between preliminary point-of-care diagnosis and expert interpretation.
Consistent with other studies, we found that non-expert echocardiographers are capable of acquiring adequate images, but their greatest limitation is in interpretation. The point-of-care diagnosis was changed in 38% of cases. It was by the availability of remote expert overread that made the use of handheld echocardiography on this medical mission possible.
What is significant about this study? What were the benefits of using a smartphone with this dedicated medical imaging software? What settings would mobile echocardiographic interpretation be most useful in?
Remote overread can support point-of-care diagnosis by non-experts using handheld ultrasound. There is minimal loss of diagnostic accuracy when interpreting echo images on a smartphone compared to a workstation using this app. Putting the two together may improve access to expert echocardiographic consultation, whether on humanitarian missions or in the domestic off-hours or “stat” evaluation setting. Furthermore, the overall cost for this system is favorable compared to previously described methods.
Will further study be performed?
We are currently investigating other uses for the Vscan as well as mVisum. Clearly, validation of smartphone-based interpretation in the traditional clinical setting of echocardiography will be needed before ultimate adoption of this technology.
- Choi BG, Mukherjee M, Dala P, et al. Interpretation of Remotely Downloaded Pocket-Size Cardiac Ultrasound Images on a Web-Enabled Smartphone: Validation Against Workstation Evaluation. J Am Soc Echocardiogr. 2011 Sep 17. [Epub ahead of print]