Equipping an ambulance with an MR scanner may not only reduce risks of death and disability in stroke patients but help determine if they should be directly transported to a community hospital or a specialized stroke center for treatment.

Neuroradiologists at the Medical University of South Carolina say that a TeleEMS program with MR scanning is possible and can help medical technicians consult with stroke specialists and jumpstart care while on the way to hospital and help physicians prepare for arrivals in advance.

Orchestrating a test run, the group drove an ambulance throughout Charleston with an MR scanner used in the back while the vehicle was in motion. Unlike CT, MR can detect smaller blockages and help doctors determine if a patient should receive the clot-busting drug, tPA or a thrombectomy. Such information may help patients with large clots bypass the current protocol of going to a tPA-capable center and instead, be directly admitted for a thrombectomy. Delaying such a procedure can eventually make patients ineligible for it due to the amount of damage they incur.

“Stroke is our primary objective because the benefits of treatments for acute stroke on patient outcomes are well established; however, these benefits are time-dependent and decrease as time to restore blood flow to the brain increases,” Dr. Donna Roberts, a professor in the department of radiology and radiological science in the College of Medicine at MUSC, told HCB News.

The idea was inspired by Roberts' research on scanning in space and other extreme conditions. The ambulance was equipped with a portable MR scanner developed by Hyperfine. The machine weighs 1,400 pounds and is smaller than the average MR scanner. It also has wheels and is primarily used to conduct brain scans at the bedside of patients in hospitals.

Roberts says that one impressive feature was the ability of the machine to correct its diagnostic imagery while the ambulance was in motion, through its automatic motion correction technology.

Every 15-minute reduction in stroke care significantly reduces risks for disabilities and mortality, according to the researchers. Some mobile stroke units have been developed to include CT scanners in ambulances, along with a critical care nurse, CT technician and paramedic. Such units are expensive, however, ranging from $600,000 to $1 million per unit. A portable MR system would be a fraction of the cost, would not expose patients to radiation, and offer the advantages of MR imaging.

The researchers see their teleEMS program as especially helpful for patients in rural areas and believe their approach is the first example of an MR scan being performed in an ambulance. They hope to conduct a pilot program in Charleston County to determine the feasibility and potential lifetime cost savings per patient. If allowed, it would enroll patients with suspected acute ischemic stroke where, when confirmed and if eligible, they would receive thrombolytic therapy while in the ambulance.

This, says Roberts, could shorten treatment times and open up thrombolytic therapy to a wider number of patients. She adds that the safety and feasibility of performing MR on patients during transport needs to be further studied and transmission speeds need to be tested in various locations, with clinical usefulness and scan quality evaluated.

“The next step is to optimize the technology to allow us to evaluate for large vessel occlusion using the Hyperfine MR,” she said. “This could change the way we triage acute strokes, and patients with large vessel occlusion, confirmed using the Hyperfine technology, could be transferred to the nearest thrombectomy-capable center without first being evaluated by the nearest stroke center.”

In addition to stroke, using an MR scanner in the back of an ambulance could help in cases of traumatic brain injury and with the use of a cervical spine coil on the Hyperfine MR, for potentially scanning neck injuries during transport.

Roberts and her colleagues are currently writing a report on their test run.