Functional MRI to Assess Brain Damage in Cardiac Arrest Patients

Assessment of Cerebral Microcirculation, Blood-brain Barrier, and Cerebral Oxygenation Damage in Patients with Cardiac Arrest Using Functional MRI

This is a single-center, observational study. Patients after successful cardiopulmonary resuscitation (CPR) will be transferred to the emergency intensive care unit for further standardized management. After successful return of spontaneous circulation (ROSC) for 72h and hemodynamics remained stable for 24h, the post-resuscitated patients underwent functional magnetic resonance imaging (fMRI) examination. During the examination, the supervising physician accompanied the patient and monitored the patient's vital signs using a magnetic resonance monitoring system (Siemens Healthcare Prism, Germany). Patients who are on ventilators are mechanically ventilated using a magnetic ventilator (HAMILTON-MRI, USA). In additional to conventional sequences, fMRI is performed for diffusion-prepared pseudo-continuous arterial spin labeling (DP-pCASL) and blood oxygenation level dependent functional magnetic resonance imaging (BOLD-fMRI). These MRI sequences allow quantitative assessment of the patients' cerebral microcirculation, blood-brain barrier, and cerebral oxygenation status. Patients will be followed up for neurologic prognosis according to the Modified Rankin Scale (mRS) at 6 months after disease onset.

Inclusion Criteria:

• age ≥18 years.
• sustained hemodynamic stability for ≥24h.
• the patients were unconscious and not able to obey verbal commands.
• Advanced life support and target temperature management within 6 hours of return of spontaneous circulation (ROSC).

Exclusion Criteria:

• Patients with hemodynamic instability.
• Patients who could not complete cranial MRI examination for special reasons.
• Patients during pregnancy.
• Patients who combined traumatic brain injury, stroke, cerebral hemorrhage and other diseases.
• Patients whose family members did not agree to be enrolled.