biostudies-literatureUnknown22(6)Yedavalli VMedium vessel occlusion (MeVO) contributes significantly to acute ischemic stroke (AIS). The hypoperfusion intensity ratio (HIR), reflecting collateral circulation via the ratio of Tmax >10s to Tmax >6s volumes, predicts infarct progression in large-vessel occlusions but is unstudied in MeVOs. In this multicenter, multinational retrospective study, we evaluated consecutive patients with MeVO who underwent mechanical thrombectomy with or without intravenous thrombolysis. Inclusion required available follow-up imaging and pretreatment CT perfusion. Follow-up infarct volume (FIV) was measured on CT or MRI 12-36 ​h post-procedure. Univariable and multivariable linear regression models were used to identify predictors of FIV, with HIR as the primary variable of interest. Among 147 patients (medNeurotherapeutics : the journal of the American Society for Experimental NeuroTherapeuticse00713https://www.ebi.ac.uk/biostudies/studies/S-EPMC12664488biostudies-literatureHypoperfusion intensity ratio is associated with follow-up infarct volume in medium vessel occlusions: A multicenter multinational study.PMC12664488Pedicelli AFilipe JPMohlenbruch MABarreau XYedavalli VFahed RQuintero-Consuegra MMAD MT InvestigatorsLi YLFaizy TDShaikh HBiswas ASalazar-Marioni SMarnat GHenninger NGuenego AGonzalez NRKuhn ALBellante FVagal AKalsoum EFuschi MDmytriw AAColasurdo MAbdalkader MHeit JJSiegler JEClarencon FRenieri LYeo LLBerge JAziz-Sultan MAKlein PForestier GMusmar BLakhani DStapleton CJEl Naamani KHecker CWintermark MSimonato DFiehler JElhorany MSchiphorst ATGriessenauer CJDofuku SHarker PPremat KCostalat VCuellar-Saenz HHScarcia LCapirossi CVarela RBaker AGopinathan ARegenhardt RWKadirvel RLiebeskind DSHsieh CYWeyland CMounayer CEssibayi MAMartinez-Gutierrez JCSibon IMowla AKiller-Oberpfalzer MPuri ASRabinov JDMeyer LKhalife JAltschul DTan BYStracke CPTancredi IAmllay AOta TJesser JDyzmann CGory BLubicz BValente IJabbour PAziz YKhandelwal PRadu RAAdeeb NSheth SPatel ABHajjeh ONguyen TNNedelcu STjoumakaris SIGhozy SKan PTThomas AJSundararajan SHDusart ASalim HAChervak LSaleme SAlexandre AMRouchaud AfalseHypoperfusion intensity ratio is associated with follow-up infarct volume in medium vessel occlusions: A multicenter multinational study.Medium vessel occlusion (MeVO) contributes significantly to acute ischemic stroke (AIS). The hypoperfusion intensity ratio (HIR), reflecting collateral circulation via the ratio of Tmax >10s to Tmax >6s volumes, predicts infarct progression in large-vessel occlusions but is unstudied in MeVOs. In this multicenter, multinational retrospective study, we evaluated consecutive patients with MeVO who underwent mechanical thrombectomy with or without intravenous thrombolysis. Inclusion required available follow-up imaging and pretreatment CT perfusion. Follow-up infarct volume (FIV) was measured on CT or MRI 12-36 ​h post-procedure. Univariable and multivariable linear regression models were used to identify predictors of FIV, with HIR as the primary variable of interest. Among 147 patients (med2025-01-01T00:00:00Z2025 Oct2026-06-05T21:33:12.605Z2026-05-22T03:11:37.452ZS-EPMC126644884082998110.1016/j.neurot.2025.e00713