Diagnose a Stroke on Your iPhone

If radiologists need another reason to justify their iPhone, it just arrived. It's now possible to diagnose strokes from scans sent to a smart-phone, using a newly developed Candian app, with positive implications for teleradiology and rural communities.

A retrospective study published May 6th in the Journal of Medical Internet Research, had two neuroradiologists reading 120 recent consecutive nonconrast CT (NCCT) brain scans, plus 70 CT angiograms (CTA) head scans from the Calgary Stroke Program database. One reader used a diagnostic workstation, the other used an iPhone or iPod Touch (iOS device). Readers looked at NCCT scans for early signs of infarction, including early parenchymal ischemic changes and dense vessel sign, excluding acute intraparenchymal hemorrhage and stroke mimics. They evaluated CTA scans for any intracranial vessel occlusion, then compared the diagnoses from both platforms.

Researchers found that the sensitivity and specificity of detecting intraparenchymal hemorrhage were 100 percent for the iOS device. As for the sensitivity, specificity and accuracy of detecting acute parenchymal ischemic change, those figures were 94.1 percent, 100 percent and 98.09 percent respectively for the first reader, and 97.05 percent, 100 percent and 99.04 percent for the second reader. In detecting vessel occlusion on CTA, the sensitivity, specificity, and accuracy were 94.4 percent, 100 percent and 98.46 percent for both readers. There was also no significant difference in the amount of time it took them to read the images on the iOS compared to the workstation.

The iOS application can view both 2-D and 3-D images, and can be manipulated by the user, with results in seconds. No patient data is stored on the iOS device, rather it’s stored on a remote, secure server. This study was designed by Mayank Goyal, MD, of the Hotchkiss Brain Institute (HBI), and the iPhone software technology was originally developed by Ross Mitchell, PhD, and others at HBI. It was then enhanced and commercialized by Calgary Scientific Inc.

The app is ResolutionMD Mobile, which can also be used on Android smart-phones and iPads, as well as web-based browsers. The computing work is done on a server, then streaming the images to the smart-phone in real time. Health Canada approved the app in April 2010, so doctors there can make primary diagnoses using it. It’s since reportedly been licensed to medical imaging companies and 50,000 hospitals, so doctors should have access to it within the next two years.