A large multi-state registry study shows that adding CTP to routine stroke imaging more than doubles EVT rates, with no increase in treatment delays.
One of the most persistent concerns about CT perfusion in acute stroke care is that it adds time. The data says otherwise.
A registry study published in Stroke (Marginean et al., 2025) analyzed 13,778 acute ischemic stroke patients across multiple states, all presenting within 6 hours of last known well. Researchers compared outcomes between patients who received CTA alone versus those who received CTA combined with CTP, controlling for NIHSS and comorbidities.
The results were significant across three dimensions:
More patients treated. The EVT rate nearly doubled — from 9.8% in the CTA-alone group to 22% in the CTA+CTP group. That's a 224% relative increase in treatment rate.
More medium vessel occlusions identified and treated. Patients with medium vessel occlusions (MeVOs) were 3.2 times more likely to receive EVT when CTP was added to the imaging protocol. This is the part that matters most: MeVOs are notoriously difficult to detect on CTA alone. CTP identifies the salvageable tissue that makes those treatment decisions defensible.
Faster door-to-needle time. Rather than adding delay, adding CTP was associated with a faster median door-to-needle time — 42 minutes compared to 47 minutes with CTA alone (p<0.001). No increase in LVO treatment delay was observed.
Stroke guidelines and recent trials have expanded to include medium vessel occlusions as a target for intervention. But MeVOs present differently than LVOs: symptoms are often subtler, imaging findings are less obvious, and clinical confidence is harder to establish without additional data.
CTP is often referred to as a “MeVO detector” by mapping the tissue-level perfusion delays by region to help determine IVT or EVT decisions, where CTA alone leaves the clinical picture incomplete.
The Marginean study makes this concrete: MeVO patients who received CTP were 3.2× more likely to receive EVT. That's not a marginal improvement. That's a meaningful shift in who gets treatment.
The finding that median DTN was faster with CTA+CTP — 42 minutes versus 47 minutes — challenges the assumption that perfusion imaging is an operational liability. When CTP is integrated into the standard workflow for all code strokes, it doesn't create delays. It can reduce them, because clinicians arrive at treatment decisions with greater confidence rather than second-guessing vague findings on CT and CTA.
This aligns with the broader clinical case for standardizing CTP across stroke networks: not as an add-on for complex cases, but as the baseline for confident decision-making.
CTP for acute ischemic stroke now has a category 1 CPT code — a signal that the evidence base has reached the threshold required for clinical standard-of-care recognition. Updated guidelines also require advanced imaging (including perfusion) to extend the TNK window from 4.5 to 9 hours from last known well, and up to 24 hours for patients ineligible for EVT.
The clinical and reimbursement case for routine CTP has aligned.
The study's headline numbers — a 224% increase in EVT rate, a 3.2× increase for MeVOs — aren't just operational metrics. They represent patients who would otherwise not have received treatment.
In a hub-and-spoke stroke network, the hospitals most likely to miss MeVOs are spoke facilities: smaller sites, less specialized radiology coverage, less familiarity with subtle perfusion deficits. When CTP is absent from those sites, patients presenting with medium vessel occlusions face a lower probability of being identified as treatment candidates — regardless of whether their tissue is still salvageable. Perfusion also provides critical information guiding the hub stroke teams during extended patient transfers.
Standardizing CTP across the network is, in effect, a decision about whether treatment access should depend on where a patient happens to arrive. The data suggests it currently does. It doesn't have to.
Does adding CTP to the stroke imaging protocol increase time to treatment?
No. The Marginean et al. (2025) multi-state registry study found that median door-to-needle time was actually faster in patients who received CTA+CTP (42 minutes) compared to CTA alone (47 minutes), with statistical significance at p<0.001. The addition of CTP did not delay LVO treatment.
What is a medium vessel occlusion (MeVO) and why is it hard to detect?
A medium vessel occlusion is a blockage in a smaller intracranial artery — such as M2, M3, or A2 segments — beyond the large vessels typically targeted in LVO protocols. MeVOs often produce subtle or atypical symptoms, making clinical identification difficult. CTA can miss them if the occlusion is distal or the vessel is small. CTP adds tissue-level information, showing where perfusion is compromised even when the vessel finding alone isn't conclusive.
Why are MeVO patients 3.2x more likely to receive EVT with CTP?
CTP identifies salvageable tissue (penumbra) around the infarcted core. In MeVO cases, this information is often what tips the clinical decision toward intervention. Without it, clinicians may lack the confidence to proceed, particularly in cases where CTA findings are equivocal.
Is CTP reimbursable for acute ischemic stroke?
Yes. CTP for acute ischemic stroke now has CPT code recognition, reflecting its established clinical value and standard-of-care status.
What guidelines require advanced imaging for extended-window thrombolysis?
Updated stroke guidelines specify that advanced imaging — including perfusion imaging — is required to extend the IVT window from 4.5 hours to 9 hours from last known well (and up to 24 hours for patients ineligible for EVT).
CTP doesn't just help in the extended time window. In acute stroke, where every minute determines how much brain can be saved, adding CTP to the standard imaging protocol identifies more treatable patients, supports better decisions for difficult presentations, and — when integrated into the workflow — doesn't add time.
The data from 13,778 patients across a multi-state registry reinforces what leading stroke programs already know: CTP is how you stop missing treatable patients.
Source: Marginean, Horia, et al. "Does the use of CT perfusion (CTP) increase treatment rate of endovascular thrombectomy (EVT) in acute ischemic stroke patients?" Stroke 56, Suppl. 1 (2025): A10–A10. Presented at the American Stroke Association International Stroke Conference 2025.
RapidAI's Rapid CTP is used in stroke centers across the U.S. to support imaging-guided treatment decisions across the complete stroke pathway.