Prognostic value of (18)F-FDG brain PET as an early indicator of neurological outcomes in a rat model of post-cardiac arrest syndrome

Predicting neurological outcomes in patients with post-cardiac arrest syndrome (PCAS) is crucial for identifying those who will benefit from intensive care. We evaluated the predictive value of 18F-FDG PET. PCAS was induced in Sprague Dawley rats. Baseline and post-3-hour images were acquired. Standardized uptake value (SUV) changes before and after PCAS induction (SUV(delta)) and SUV ratios (SUVR) of regional SUV normalized to the whole brain SUV were obtained. The Morris water maze (MWM) test was performed after 2 weeks to evaluate neurological outcomes and rats were classified into two groups based on the result. Of 18 PCAS rats, 8 were classified into the good outcome group. The SUV(delta) of forebrain regions were significantly decreased in good outcome group (p < 0.05), while the SUV(delta) of hindbrain regions were not significantly different according to outcomes. The SUVR of forebrain regions were significantly higher and the SUVR of hindbrain regions were significantly lower in good outcome group (p < 0.05). Forebrain-to-hindbrain ratio predicted a good neurological outcome with a sensitivity of 90% and specificity of 100% using an optimal cutoff value of 1.22 (AUC 0.969, p < 0.05). These results suggest the potential utility of 18F-FDG PET in the early prediction of neurological outcomes in PCAS.