Contrast-enhanced ultrasound ventriculography

During external ventricular drainage (EVD) weaning, cranial computed tomography (cCT) is necessary to evaluate ventricle width. Because intrahospital transfer of critically ill patients is associated with higher mortality, bedside techniques are necessary to evaluate ventricle width. Transcranial sonography is able to show the ventricles in patients with sufficient temporal acoustic window. Contrast-enhanced ultrasound (CEUS) is able to overcome the limitations of insufficient insonation.

We demonstrate the feasibility of bedside transcranial CEUS ventriculography to measure ventricles and verify the passage of cerebrospinal fluid (CSF) through the foramen of Magendie into the subarachnoid space during EVD weaning in critically ill patients.

Six patients were examined by transcranial and transnuchal CEUS. Harmonic imaging with low mechanical index was used. One milliliter of an ultrasound contrast agent was administered via EVD line. Comparison with the cCT scans at the time of discharge was used to confirm CEUS-ventriculography results.

Ventricles were visualized in all patients. CSF transmission via the foramen of Magendie was demonstrated in 5 patients. Mean ventricle width (centimeters) was 0.67 (CEUS) vs 0.73 (cCT) (standard deviation 0.43, 0.45, P = .116) [third ventricle], 0.88 vs 1.02 (0.28, 0.22, P = .055) [fourth ventricle], 1.40 vs 1.37 (0.56, 0.54, P = .620) [left lateral ventricle], 1.37 vs 1.37 (0.55, 0.54, P = .952) [right lateral ventricle], 2.33 vs 2.23 (0.51, 0.58, P = .169) [left anterior horn], and 2.25 vs 2.07 (0.56, 0.64, P = .204) [right anterior horn]. Mean duration for CEUS ventriculography was 3:15 minutes.

CEUS ventriculography is an effective bedside procedure in critically ill patients with EVD. CEUS allows measurement of ventricle width, ventricle communication, and CSF transfer to the subarachnoidal space through the cisternal foramina.