Deans' stroke musings: Perfusion Mismatch Ratio Predictive in Medium Vessel Occlusion Strokes

Changing stroke rehab and research worldwide now.Time is Brain! trillions and trillions of neurons that DIE each day because there are NO effective hyperacute therapies besides tPA(only 12% effective). I have 523 posts on hyperacute therapy, enough for researchers to spend decades proving them out. These are my personal ideas and blog on stroke rehabilitation and stroke research. Do not attempt any of these without checking with your medical provider. Unless you join me in agitating, when you need these therapies they won't be there.

What this blog is for:

My blog is not to help survivors recover, it is to have the 10 million yearly stroke survivors light fires underneath their doctors, stroke hospitals and stroke researchers to get stroke solved. 100% recovery. The stroke medical world is completely failing at that goal, they don't even have it as a goal. Shortly after getting out of the hospital and getting NO information on the process or protocols of stroke rehabilitation and recovery I started searching on the internet and found that no other survivor received useful information. This is an attempt to cover all stroke rehabilitation information that should be readily available to survivors so they can talk with informed knowledge to their medical staff. It lays out what needs to be done to get stroke survivors closer to 100% recovery. It's quite disgusting that this information is not available from every stroke association and doctors group.

Sunday, October 25, 2026

Perfusion Mismatch Ratio Predictive in Medium Vessel Occlusion Strokes

Since NOTHING WILL BE DONE with this to get survivors recovered; TOTALLY FUCKING USELESS! With NO leadership or strategy in stroke, better plan on not having one! Prognostication alone has never gotten anyone recovered; prove me wrong, you blithering idiots!

Perfusion Mismatch Ratio Predictive in Medium Vessel Occlusion Strokes

Small trial suggests potential for CT imaging measure in prognostication, treatment selection

by Crystal Phend, Contributing Editor, MedPage Today

October 15, 2026 • 3 min read

For medium vessel occlusion strokes, perfusion mismatch ratio predicted follow-up infarct volume, a multinational trial showed, supporting a role similar to that in large vessel occlusion.

In the 94 isolated M2-segment occlusion patients studied, higher mismatch ratio had a beta score of -0.26 (95% CI -0.37 to -0.14, P<0.001) for smaller follow-up infarct volume. The relationship remained significant on multivariate analysis (beta -0.14, 95% CI -0.27 to -0.02, P=0.026).

However, absolute mismatch volume -- hypoperfused volume minus the ischemic core volume -- wasn't predictive (P=0.84), Hamza Adel Salim, MD, of the University of Texas MD Anderson Cancer Center in Houston, reported at the at the American Society of Functional Neuroradiology meeting in Newport Beach, California.

Mismatch ratio -- a CT-based calculation of the volume of hypoperfused tissue that is potentially salvageable to the volume of the irrecoverable ischemic core -- has largely been studied in large vessel occlusion stroke. Clinical trials have shown strong benefit of both thrombolytics and endovascular thrombectomy among patients with higher mismatch, although low mismatch hasn't necessarily proven a good rule out for thrombectomy selection.

"The performance of mismatch ratio in this population was consistent with its performance in large vessel occlusion," Salim told MedPage Today. "Predictive value was consistent with what we expected."

But unlike in large vessel ischemic strokes, trials have had mixed results on benefit of mechanical thrombectomy in distal medium vessel occlusion, he noted: "So the question that needs to be answered here is which distal medium vessel occlusion patient could benefit from thrombectomy? In this study, we've shown that mismatch ratio does represent fall of infarct volume in these patients. So this study should pave the way for future studies that could assess whether the treatment of distal medium vessel occlusion patients who had low mismatch ratio is not that beneficial compared to patients who have high mismatch ratio."

The study included 94 patients in an international registry with prospectively collected data who had been treated from September 2017 through July 2021 for acute ischemic stroke with isolated M2-segment occlusion. Participants had to have baseline perfusion imaging and follow-up CT or MRI for infarct volume assessment.

Other predictors of greater follow-up infarct volume were higher baseline NIH Stroke Scale score, lower Alberta Stroke Program Early CT Score (ASPECTS), and right-sided occlusion (all P<0.05).

Limitations centered on the retrospective observational design, which made selection bias and residual confounding possible. The small cohort was predominantly treated with thrombectomy, limiting treatment comparisons, and the local perfusion processing and CT/MRI-based infarct measurements varied across centers.

Also, high mismatch ratios are sensitive to small estimated core volumes, the researchers cautioned. They called for prospective external validation to confirm mismatch ratio as a biomarker to triage patients for mechanical thrombectomy.

Salim emphasized that the study did not establish that patient's treatment should be selected based on mismatch ratios in medium vessel occlusion stroke.

It might be useful in the clinical framework as a complement to imaging-based prognostication, he said. However, pending trials demonstrating utility in treatment selection, "its use should be exclusive to the prognosis to tell patients or their families or the clinicians or the neurologists that in these patients we expect to have higher follow-up infarct volume compared to patients who had high mismatch ratio," Salim said.