Vascular pulsations in the rat brain visualized by EVEnt-Recurring ZTE (EVER-ZTE)

Motivation: Brain vascular pulsations are difficult to detect in the rat brain because they occur at a much faster frequency (5 - 7 Hz) than the volume TR (0.5 - 1 Hz). Goal(s): To detect vascular pulsations in the rat brain with EVEnt-Recurring ZTE approach. Approach: Event-recurring resampling to 8-9 ms temporal resolution was applied to resting-state rat ZTE fMRI data measured under isoflurane anesthesia. Heartbeat timings were estimated from simultaneous ECG measurements. Results: Pulsations and brain-wide pulse wave propagations were clearly detected during one heartbeat cycle. As ZTE sequence has a strong in-flow contribution, the pulsation was most visible in the main cerebral arteries. Impact: EVER-ZTE enables the robust detection of brain vascular pulsations in preclinical settings, providing a unique opportunity to measure non-invasively critical physiological parameters linked to brain health at the same time with traditional fMRI measurement.