Portable CT device shortens request-to-scan times, increases number of stroke patients eligible for tPA treatment

The availability of a portable CT scanner in an emergency room significantly increases the number of patients who are eligible for life-saving treatment.

In a study conducted at North Shore Medical Center in Salem, MA, stroke triage was monitored to determine the effect that rapid access to CT scans would have on treatment of stroke.

"There is only one agent available and approved by the FDA for treatment of an acute ischemic stroke, and that is tissue plasminogen activator," said Dr. David Weinreb, the lead investigator and a radiology resident at the Hospital of Saint Raphael in New Haven, CT.

Hemorrhage is a potential -- and potentially dangerous -- side effect of tPA, Weinreb said. And the drug must be administered within three hours of symptom onset.

"Usually, when patients arrive at the emergency department, they have already passed the three-hour limit," he said. "The challenge is to determine which patients are eligible for use of tPA."

A head CT must be performed before tPA can be administered, to confirm there is no bleeding. For patients who have not yet passed the three-hour time limit for tPA eligibility, a delay obtaining the CT scan reduces their chances of receiving the drug.

For one month before and four months after the installation of the portable scanner, researchers recorded how much time elapsed between a physician's request for a head CT for a stroke patient and performance of the scan. After the portable CT scanner was installed, request-to-scan times fell from an average of 34 minutes to 16 minutes.

The device is only large enough for head scans and can be kept in the emergency department. In the study it eliminated the need to move patients to the radiology department -- or even from the stretcher onto the CT table.

According to Weinreb, computer simulations of the consequences of the time reduction showed that the introduction of a portable CT scanner would double the number of patients eligible for tPA treatment.

"Based on these data, the most practical and potentially effective strategy to increase patient eligibility is to decrease request-to-scan times," Weinreb said.