# Serial Physiologic MRI in Minor Stroke with Large Vessel Occlusion

> **NIH NIH R21** · UNIVERSITY OF PENNSYLVANIA · 2022 · $243,750

## Abstract

PROJECT SUMMARY
Mechanical thrombectomy (MT) has revolutionized the treatment of stroke due to large vessel occlusion (LVO)
in patients with moderate or severe stroke symptoms. However, clinical management remains controversial in
LVO patients with relatively minor deficits because these patients were not well represented in the MT clinical
trials. Up to one third of patients with LVO and minor deficits will experience early neurologic deterioration (END)
which portends significant long-term disability. Observational studies, though conflicting and limited by selection
bias, suggest that some of these patients may benefit from early MT, but it remains challenging to predict END
and waiting for END to pursue MT has been associated with poor functional outcome. The development of
predictive biomarkers for END represents a critical need for the optimization of MT therapy in patients with LVO
and relatively mild clinical deficits.
In moderate or severe stroke with LVO, contrast based perfusion imaging indicates the presence of an ischemic
penumbra based on prolonged transit time, and has been crucial in optimizing patient selection and extending
the time window for MT. However, the role of contrast based perfusion imaging is less clear in LVO patients with
minor clinical deficits because prolonged transit time in this patient population does not reliably predict eventual
infarction. Further, current imaging strategies are limited to a snapshot in time and thus fail to account for the
dynamic nature of tissue physiology and function. END is a consequence of progressive loss of collateral blood
flow supplying the ischemic penumbra, but the paucity of data on the early temporal evolution of the ischemic
penumbra remains a key knowledge gap for predicting clinical outcomes such as END.
This project will leverage the availability of research MRI within a new stroke and neurointensive care unit to
characterize the temporal evolution of penumbral blood flow and oxygen metabolism in LVO patients with NIH
stroke scale (NIHSS) < 6, within the first 24 hours of symptom onset. A unique aspect of this study will be the
use of serial MRI scanning to quantify short-term changes in penumbral physiology. The scanning protocol will
also leverage innovative MRI methodologies for noninvasively mapping cerebral blood flow and tissue oxygen
extraction. We hypothesize that serial MRI will identify flow and metabolic deterioration in advance of clinical
deterioration and with greater sensitivity than standard clinical single time point imaging. This exploratory R21
project will validate a novel imaging strategy, provide new insights into the evolution of the ischemic penumbra
during the hyperacute phase of ischemic stroke, and provide critical data needed to design future studies using
this approach to personalize clinical care of stroke patients with LVO and minor deficits.

## Key facts

- **NIH application ID:** 10432419
- **Project number:** 1R21NS126862-01
- **Recipient organization:** UNIVERSITY OF PENNSYLVANIA
- **Principal Investigator:** JOHN A DETRE
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $243,750
- **Award type:** 1
- **Project period:** 2022-04-01 → 2024-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10432419

## Citation

> US National Institutes of Health, RePORTER application 10432419, Serial Physiologic MRI in Minor Stroke with Large Vessel Occlusion (1R21NS126862-01). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/10432419. Licensed CC0.

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