Fig. 1

Various findings of ultra-early DW-MRI scan and ADC in OHCA patients. (a) Regional involvement. Gyriform HSI is observed in only a portion of the occipital lobe (white arrow). The patient presented with a witnessed arrest with bystander CPR. The first monitored rhythm was a non-shockable rhythm and serum lactic acid level was 11.0 mmol/L. The ROSC to DW-MRI scan-interval remained at 3.1 h. The low-flow time was 22 min. (b) Multi-regional involvement. HSIs are observed in both the occipital lobes and basal ganglia. The patient presented with an unwitnessed arrest with bystander CPR. The first monitored rhythm was a non-shockable rhythm, and the serum lactic acid level was 3.8 mmol/L. The ROSC to DW-MRI scan-interval was 2.7 h. The low-flow time was 38 min. (c) Multi-focal pattern. HSI findings, resembling emboli, are observed in the occipital and temporal lobes except white matter. The patient presented with a witnessed arrest with bystander CPR. The first monitored rhythm was shockable, and the serum lactic acid level was 13.3 mmol/L. The ROSC to DW-MRI scan-interval was 1.7 h. The low-flow time was 47 min. (d) Global involvement. HSI is observed in the occipital and temporal lobes, indicating severe HIBI. The patient presented with an unwitnessed arrest with no-bystander CPR. The first monitored rhythm was non-shockable rhythm and the serum lactic acid was 8.7 mmol/L. The ROSC to DW-MRI scan-interval of 2.9 h. The low-flow time was 7 min. OHCA, out-of-hospital cardiac arrest; DW-MRI, diffusion-weighted magnetic resonance imaging; ADC, apparent diffusion coefficient; ROSC, return of spontaneous circulation; HSI, high-signal intensity; CPR, cardiopulmonary resuscitation.