CT is making its way to the healthcare frontline as an invaluable diagnostic tool within the emergency department—and challenging MR, particularly in stroke imaging. With quicker, high slice-count scanners, EDs are scanning critical patients at unprecedented speeds, setting benchmarks for advanced cardiovascular and cerebrovascular imaging while simultaneously improving diagnostic accuracy and lowering radiation doses.
Stroke imaging has changed at St. Elizabeth’s Medical Center in Edgewood, Ky., with high slice-count volume CT being the new technology of choice. Time is brain in stroke imaging and the U.S.-accredited Stroke Center is speeding time to diagnosis with CT brain perfusion and coronary CT angiography (CTA) studies in the ED on the Aquilion ONE volume CT (320 slice) from Toshiba America Medical Systems. Each day, they’re performing approximately 40 to 60 CT studies, according to Director of Imaging Jeff Dardinger, MD.
“We are moving away from MR to using CT the majority of the time,” Dardinger says. It’s all about time—brain CT protocol for stroke takes about 1 minute and the total exam takes about 10 minutes versus the one to three hours it can take to complete an MR study, he adds.
Outside of stroke imaging, the team at St. Elizabeth’s is using CTA to look for pulmonary emboli—another area they have seen great improvement in images and reductions in radiation exposure. “With the new scanner, because it does volume imaging, we get no motion artifact around the heart and we are getting higher quality pictures with half the radiation dose,” he adds.
When a patient presents in the ED with symptoms of a stroke or heart attack, any delay could mean brain cells and heart cells are dying. “With Aquilion, we are getting patients into the CT scanner faster than ever before,” he adds.
Pedro Diaz, PhD, vice chair of imaging and informatics systems for Metro Health Medical Center in Cleveland, Ohio, sees the same CT surge in the ED, especially for imaging patients presenting with stroke symptoms. In 2007, 60 percent of CT scans performed throughout their entire system were performed in the ED—up from 40 percent in 2003.
The U.S.-accredited stroke/Level I trauma center at MetroHealth is using the Brilliance Essence 64 from Philips Healthcare. Diaz has noticed a trend of doing not just routine types of CT screenings, but using CT for more sophisticated screenings as well.
“We have the capacity to not only assess if there is a bleed, but also do a brain perfusion study to determine tissue viability and more accurately identify a case that is outside the routine temporal window for administering clot busters,” he says. “We now routinely do a head CT followed by a CTA of the head and neck, to determine the status of the vasculature to plan treatment.”
While MR has long been the contender for brain perfusion, it is now getting competition from multidetector CT systems that offer faster acquisition and processing times.
“MR is more established for brain perfusion studies, however, taking an ED patient to the MR suite, not to mention the time required to do the MR study, is a challenge,” Diaz says. “A CT study that might be slightly inferior but can be done in a matter of seconds in the ED offers a compelling alternative.” Another area where Diaz says CT has great potential is in chest pain, using cardiac CTA studies to assess patients. “As cardiac CTA screening gains acceptance, the ED may be the first place where we see it routinely used,” he concludes.
While the MR versus CT debate continues, what is clear is that as CT utilization continues to increase in the ED, more hospitals will recognize the benefits and cost-savings that can be realized by investing in frontline imaging tools to ultimately, improve the quality of patient care.