# Dynamic Cerebral Perfusion Electrical Impedance Tomography: A Neuroimaging Technique for Bedside Cerebral Perfusion Monitoring During Mannitol Dehydration

## TL;DR

This study introduces a new non-invasive imaging technique to monitor brain perfusion in real-time during a medical treatment for cerebral damage.

## Contribution

Dynamic cerebral perfusion electrical impedance tomography (DCP-EIT) is proposed for real-time bedside cerebral perfusion monitoring during dehydration therapy.

## Key findings

- DCP-EIT successfully visualized cerebral perfusion changes consistent with CT-identified ischemic areas.
- RY values in patients with neurological dysfunction remained elevated significantly longer than baseline after dehydration.
- DCP-EIT shows potential for optimizing individualized cerebral protection strategies in neurocritical care.

## Abstract

Mannitol dehydration is routinely used to prevent and treat cerebral damage after total aortic arch replacement (TAAR), but existing neuroimaging technologies cannot achieve bedside real-time quantitative assessment of its impact on cerebral perfusion in different patients. This study applied dynamic cerebral perfusion electrical impedance tomography (DCP-EIT), a non-invasive neuroimaging technique, for bedside cerebral perfusion monitoring in TAAR patients during dehydration. Seventeen patients with normal neurological function and nineteen with neurological dysfunction (ND) were enrolled. The variation patterns and differences in perfusion impedance, images, and the relative ratios (RY) of mean perfusion velocity (MV), height of systolic wave (Hs), inflow volume velocity (IV), and angle between the ascending branch and baseline (Aab) were analyzed. Results showed DCP-EIT could visualize cerebral perfusion changes, with detected poorly perfused regions showing good consistency with ischemic areas identified by computed tomography (CT). RY of normal patients fluctuated around 0.97–1.04, with no significant difference from baseline. RY of ND patients peaked at 14–20 min after dehydration and remained higher than baseline even at 100 min (p < 0.001). DCP-EIT holds potential to optimize individualized cerebral protection strategies for other cerebral damage scenarios and neurocritical care.