Overview

The primary goal of neurocritical care is to prevent secondary brain injury, which worsens neurological outcomes. Because clinical monitoring is often insufficient due to the patient's condition and medical treatments, multimodal monitoring using biophysical, electrophysiological, and imaging data is essential. In patients with subarachnoid hemorrhage (SAH), the most frequent and severe complication is delayed cerebral ischemia, often linked to arterial vasospasm and potentially leading to infarction. Early diagnosis combines transcranial Doppler (TCD), sensitive to vasospasm, with perfusion CT (CTP), which measures cerebral perfusion; this approach guides therapy and improves prognosis. Ultrasound, especially when enhanced with contrast agents (CEUS), allows non-invasive, bedside, repeated visualization of cerebral blood flow and perfusion-even through the skull. Agents like SonoVue® help quantify perfusion using time-intensity curves. The study aims to assess whether cerebral perfusion measurements from the SYLVER device are equivalent to those from CTP in ICU or CCU patients.

Eligibility

Inclusion Criteria:

• Patient ≥ 18 years old
• Patient Informed Consent, or from his/her relative if the patient is not conscious and able to consent
• Admission to ICU or CCU with indication to perform at least one CTP
• Affiliated with or benefiting from a social security scheme
• The subject's current clinical status, as assessed by medical history, physical examination, and/or relevant tests, indicates that they do not require immediate medical treatment or emergency care at the time of enrolment.

Exclusion Criteria:

• Guardianship, curatorship or any deprivation of liberty by judicial or administrative decision
• Pregnant or breast-feeding women
• Known contra-indication or hypersensitivity to SonoVue® (to sulfur hexafluoride microbubbles or to one of its excipients such as polyethylene glycol (PEG))
• Right-to-left shunts
• Patients who have undergone craniectomy in the temporal region
• Patients with open wounds or recent scars in the temporal region
• Unstable hemodynamic or respiratory state contraindicating transportation to CTP scanner