Lesion water content on noncontrast CT (net water uptake, NWU) predicts 12-month functional outcome and modifies the effect of thrombectomy in large-core stroke, and follow-up NWU is the strongest single imaging predictor and also predicts late mortality.
Among large-core stroke patients in TENSION, outcomes at 12 months were poor, with high mortality and few patients reaching mRS 0-3.
Higher baseline NWU independently predicted worse 12-month functional outcome.
Baseline NWU modified the treatment effect of endovascular thrombectomy (EVT).
Follow-up NWU at 24 hours was the strongest single imaging predictor of 12-month outcome and superseded baseline NWU when both were modeled together.
Higher follow-up NWU independently predicted late mortality among 90-day survivors.
The authors conclude that CT-derived lesion water content may be a clinically accessible biomarker linking baseline treatment-modifiable injury with realized post-treatment injury and long-term outcome.
This study looked at patients with large strokes, where a big area of the brain is already badly damaged, and asked whether a measurement from a routine CT scan could help predict recovery. The measurement, called net water uptake, reflects how much water has built up in the injured brain tissue. It was analyzed using data from a clinical trial (TENSION) of clot-removal procedures (thrombectomy) in 198 patients. Outcomes in this group were generally poor: after 12 months, 23% had a good-to-moderate functional outcome (able to walk, at least with help) and 56% had died. Patients whose scans showed more water in the injured tissue at admission tended to do worse, and this measure was a better predictor than the commonly used ASPECTS score. The amount of water also appeared to change how much benefit patients got from thrombectomy. Water content on a scan taken 24 hours after treatment was an even stronger predictor of long-term outcome and was linked to later death among those who survived the first 90 days. This research suggests that a simple CT-based measure could help doctors better understand which large-stroke patients are likely to benefit from treatment and how they may fare over time. However, this was a secondary analysis of an existing trial with a relatively small number of patients, so the findings would need confirmation in further studies before being used in practice.
Broocks G, Bendszus M, Hohenstatt S, Simonsen C, Thomalla G, Gizewski E, et al.. (2026). Lesion Water Content on CT Predicts 12-Month Outcome and Modifies Thrombectomy Effect in Large-Core Stroke-A Secondary Analysis of the TENSION Trial.. Translational stroke research. https://doi.org/10.1007/s12975-026-01501-1