Old Technology Finds New Purpose

Radiologists use sonar to diagnose stroke

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) For almost a century, sonar has helped submarines find their way through mysterious waters. Now, researchers have found that sonar technology can be used to identify and diagnose stroke.

Researchers have created a new tool that can detect and find different types of stroke and brain injury. The tool - which is based on submarine technology - involves only a simple headset and a laptop-based device.

Because the tool is so small and portable, it will be helpful in places other than the hospital, including battle zones where military doctors need to quickly judge situations and deliver care to soldiers in need.

dailyRx Insight: Ask your doctor if they use software based upon sonar technologies.

Because the tool continuously checks a patient's condition, it can detect changes immediately, making it perfect for use in field emergencies, ambulances, and military settings, says Dr. Kieran J. Murphy, director of research and deputy chief of radiology at the University of Toronto.

On top of its usefulness in the field, researchers hope that the tool will be used in other areas - such as open heart surgery - where the threat of stroke is a constant concern. They also hope it will be used to detect other vascular conditions as well as to track the progression of disease when testing drugs.

The tool works by measuring brain pulsations with an array of sensors. It then sends information back to doctors about where and what kind of abnormalities have been found. Murphy explains, "As sonar sorts out whales and other objects from vessels, the device sorts out cerebral abnormalities such as aneurysms, arteriovenous malformations (abnormal connections between veins and arteries), ischemic strokes, and traumatic brain injury from normal variations in physiology."

Researchers tested the tool on 16 men and 24 women who had a variety of health problems concerning the brain and vascular system. The tool was able to tell the different between normal conditions in 30 healthy subjects and other conditions in the patients with health problems.

Stroke affects almost 6 million Americans every year, and it is the second leading cause of death. A stroke happens when blood flow to the brain is interrupted, either by a blood clot in the brain or from another part of the body (ischemic stroke), or by a blood vessel in the brain breaking open from high blood pressure (hemorrhagic stroke). In most cases, stroke causes significant disability and requires intense rehabilitation to regain lost function from the damaged brain. Symptoms vary depending on which part of the brain is being affected, but commonly referenced symptoms are a sudden weakness or numbness on one side of the body or face, and the inability to speak clearly or find words. Diagnosis and management are medical emergencies. If the stroke is caught early and is being caused by a blood clot, there are medications, such as tPA (tissue plasminogen activator, Activase) that can be given to quickly dissolve the clot. Hemorrhagic strokes often need brain surgery to stop bleeding. Patients are usually given a host of imaging tests, such as CT scan, MRI, and angiogram (x-ray of the blood vessels).

Information about this stroke-monitoring device was presented at the 36th Annual Scientific Meeting of the Society of Interventional Radiology. 

Reviewed by: 
Review Date: 
March 29, 2011
Last Updated:
March 30, 2011