Neurology: What do you know about DWI reversals?

Within a few minutes of stroke, acute ischemia can be shown on dWIAlthough DWI lesions are thought to represent irreversible injury of ischemic tissue (ischemic core), animal and human studies suggest that some DWI lesions are reversible if blood flow recovers quicklyin different studies, there are several ways to identify DWI reversal (DWI reversal, DWIR) phenomenon, usually comparing the difference between the baseline DWI abnormal volume and the final lesions volume of the following imaging techniques: DWI for a few hours to one week of stroke, 290 days of stroke follow-up flair, 3stroke 90-day T2 sequencein March 2020, Nandakumar Nagaraja and others from the United States published their systematic review on Neurology, aimed at clarifying the incidence, predictors, and clinical significance of DWIRThe main criteriaincluded DWI scans within 24h of stroke and follow-up dWI or Flair/T2 sequences within 7 daysA total of 23 studies met the criteriaIn DWI-based studies, the incidence of DWIR was 26.5%, and in Flair/T2-based studies, the incidence rate of DWIR was 6%DWIR is associated with reflux or re-perfusion of ischemic tissue (whether t-PA or intravascular therapy), early treatment of t-PA, intravascular treatment in a short period of time after MRI, and lack or less severe perfusion defects in DWI lesionsDWIR is associated with early neurofunctionimprovement and long-term prognosis, possibly due to reperfusion, the authors summarize the factors associated with DWIR, including:, clinical factors1.t-PA early treatment
2.EVT (hydrant) early treatment, especially the short time from DWI to EVT
II, imaging factors1reflux or full re-injection of ischemic tissue
Injection defects or non-severe perfusion defects3Possible MCA remote branch ingresssening instead of large blood vessel scones4Possible DWIRs are located in white instead of gray matter5Large or small DWI damage6Although DWIR damage has a higher baseline average ADC value or average ADC ratio (compared to No DWI damage), but no absolute The ADC boundary value or average ADC ratio distinguishes DWIR damage from irreversible damage
the final authors believe that DWIR is seen in 1/4 of acute ischemic stroke, which is associated with good clinical prognosis after re-perfusionThe findings highlight dWI's shortcomings in identifying early ischemic cores