What the study found
Researchers at Michigan Medicine analyzed 2,151,408 weighted emergency department visits for transient ischemic attack (TIA) — commonly called a "mini stroke" — using the National Emergency Department Sample, a nationally representative database maintained under the Healthcare Cost and Utilization Project. The study, published in JAMA Neurology and covered by Radiology Business, tracked TIA visits from 2013 through 2021 (patients were 55.5% female, mean age 69.8).
The topline finding: the predicted probability of discharging a TIA patient straight from the ED, rather than admitting them, rose from 45% in 2013 to 66% in 2021 (p<0.001). TIA care is moving out of a short inpatient stay and into a single, imaging-heavy emergency department visit.
Advanced imaging use is climbing fast
That discharge-first approach is backed by a sharp rise in advanced imaging. Among TIA patients discharged from the ED, predicted CT angiography (CTA) use rose from about 4% in 2013 to 45% in 2021 — more than a tenfold increase. Predicted MRI use rose from 17% to 53% over the same span. Mean ED charges per TIA encounter rose from $1,746 to $2,755.
None of this is incidental. Guidelines call for a multimodal neurovascular workup — brain imaging plus vessel imaging of the head and neck — to rule out the causes of TIA most likely to lead to a full stroke within days: large-vessel narrowing, carotid disease, or a cardioembolic source. CT and CTA are what let an ED clinician make a same-day discharge decision with any confidence instead of defaulting to a hospital bed to "watch and wait."
| Measure | 2013 | 2021 |
|---|---|---|
| Same-visit ED discharge (predicted probability) | 45% | 66% |
| CTA use among discharged TIA patients | 4% | 45% |
| MRI use among discharged TIA patients | 17% | 53% |
| Mean ED charge per TIA visit | $1,746 | $2,755 |
Figures reflect predicted/adjusted probabilities from the National Emergency Department Sample, 2013–2021, as reported in the underlying JAMA Neurology study.
The rural-urban gap inside the same trend
The study also found that discharge rates were consistently higher in rural EDs than urban EDs across every year studied — but MRI use was consistently lower in rural encounters. In other words, rural emergency departments are adopting the discharge-first model just as readily as urban ones, without matching access to the full imaging workup that model depends on.
That gap matters because a discharge-first strategy only works if the imaging comes back fast enough, and complete enough, to actually rule out a stroke precursor before the patient walks out the door. A rural ED that can get a CT and CTA but has no continuous on-site neuroradiology coverage to read it quickly is carrying the same clinical pressure as a well-staffed urban stroke center, with less infrastructure to meet it.
Why stroke-adjacent CT reads can't sit in a backlog
A TIA is, by definition, a warning that resolved on its own — which is exactly what makes it dangerous to under-read. The entire premise of same-day ED discharge is that the imaging ruled out a vessel problem likely to cause a disabling stroke in the following days. If that CTA sits in an overnight queue, the clinical decision it's supposed to inform either gets delayed (defeating the purpose of expedited evaluation) or gets made without it.
That's a reporting-capacity problem as much as an imaging-volume problem. Scanning more TIA patients with CTA is only a net improvement in care if every one of those studies gets a timely, accurate read — and that's precisely where EDs without 24/7 in-house neuroradiology, disproportionately rural ones, feel the strain first.
Where xAID fits
AI-assisted CT reporting is built for exactly this kind of volume-and-urgency combination: a structured draft of the head/neck CTA findings generated within minutes of acquisition, with xAID's in-house radiologist reviewing every preliminary and the report delivered ready-to-sign to the hospital's reading radiologist. For an ED — rural or urban — running more TIA patients through CT and CTA without a matching increase in radiologist hours, that turnaround is the difference between imaging that actually supports a same-day discharge decision and imaging that just adds another study to the overnight pile.
Frequently asked questions
What does a mini stroke look like on a CT scan?
A transient ischemic attack (TIA), often called a "mini stroke," frequently shows no visible damage on a plain CT scan because symptoms resolve before permanent tissue injury occurs. That's exactly why emergency departments pair CT with CT angiography (CTA) of the head and neck — to look for the narrowed or blocked blood vessels that caused the episode and that put the patient at risk of a full stroke in the days that follow, even when the brain tissue itself looks normal on CT.
Why is CT and CTA use rising for TIA in emergency departments?
A national study of more than 2.1 million US emergency department visits for TIA, published in JAMA Neurology, found that the predicted use of CT angiography among discharged patients rose from about 4% in 2013 to 45% in 2021, and MRI use rose from 17% to 53% over the same period. EDs are increasingly using same-visit advanced imaging to risk-stratify TIA patients for discharge rather than admitting them for observation.
Are more TIA patients being discharged from the ED instead of admitted?
Yes. The same study found the predicted probability of same-visit ED discharge for TIA rose from 45% in 2013 to 66% in 2021. Researchers describe this as a shift of care that used to happen during a short hospital admission into a single, imaging-intensive emergency department visit.
Do rural emergency departments keep up with urban EDs on TIA imaging?
Not evenly. The study found discharge rates were higher in rural EDs than urban EDs throughout 2013-2021, but MRI use was consistently lower in rural encounters. Rural EDs are adopting the same expedited, discharge-first approach without matching access to the full imaging workup guidelines recommend, which raises questions about equitable TIA care.
Why does CT reporting speed matter for mini-stroke patients?
TIA is a warning sign — a meaningful share of patients go on to have a full stroke within days, which is why a discharge-first ED strategy depends on getting the head/neck CT and CTA read quickly rather than overnight. AI-assisted drafting tools can flag and structure a CTA study for radiologist review within minutes of acquisition, which matters most in EDs, including many rural ones, without continuous on-site neuroradiology coverage.
Source: Mamer LE, et al. "Changing Patterns of Transient Ischemic Attack Evaluation in US Emergency Departments," JAMA Neurology (2026), doi.org/10.1001/jamaneurol.2026.3812, as reported by Radiology Business. Figures are rounded as reported.