Evaluation of Intracranial Pressure in Patients with Severe Brain Injury Using Contrast-Enhanced Ultrasound: A Pilot Study with Preliminary Findings.

BACKGROUND

Contrast-enhanced ultrasound (CEUS) has great potential for assessing increased intracranial pressure (ICP); however, the most appropriate parameters remain unknown. This study aimed to explore the application of quantitative analysis of CEUS diagnosing increased ICP in patients with severe brain injury after surgery, and to provide a novel idea for the non-invasive evaluation of ICP.

METHODS

This observational study included 34 patients with craniocerebral injuries admitted to the intensive care unit from May 2022 to December 2023. Patients were divided into a normal cranial pressure group (< 20 mm Hg) and an intracranial hypertension group (≥ 20 mm Hg) on the basis of the invasive ICP monitoring values. All patients underwent CEUS examination within 24 h postoperatively. Time-intensity curves of the central retinal artery and short posterior ciliary artery were generated using CEUS quantitative analysis software. Quantitative parameters were obtained, and the difference was calculated. The diagnostic accuracy of each parameter was assessed by computing the area under the receiver operating characteristic curve (AUC).

RESULTS

In total, 15 patients (44%) had intracranial hypertension. The arrival time difference (ΔAT) and peak time difference (ΔTP) were significantly higher in the intracranial hypertension group than in the normal cranial pressure group (P < 0.001 and P = 0.010, respectively). The peak intensity difference (ΔPkI) was significantly lower in the intracranial hypertension group than in the normal cranial pressure group (P = 0.025). The diagnostic accuracy of ΔAT for identifying intracranial hypertension was excellent, with an AUC of 0.944 [95% confidence interval (CI) 0.874-1.014], which yielded an optimal cutoff value of 0.86 s with 93.3% sensitivity (95% CI 0.849-1.017) and 84.2% specificity (95% CI 0.719-0.964). The AUC of ΔAT was significantly higher than that of ΔTP and ΔPkI (AUC 0.761 and 0.721, respectively; both P < 0.05).

CONCLUSIONS

The CEUS quantitative analysis parameter, ΔAT, is a promising parameter for evaluating postoperative ICP elevation in patients with severe brain injury.