Correlation of Transcranial Color Doppler Indices with Direct Measurement of Intracranial Pressure

Abstract Elevated intracranial pressure (ICP) is a neurological emergency requiring prompt intervention. While invasive ICP monitoring is the gold standard, it carries risks such as infection and hemorrhage. This study evaluated the correlation between transcranial color Doppler (TCCD) indices and directly measured ICP in patients undergoing cerebrospinal fluid (CSF) diversion procedures. In this prospective observational study, 50 adult patients scheduled for CSF diversion were enrolled. TCCD measurements of middle cerebral artery flow velocities—peak systolic velocity (PSV), end-diastolic velocity (EDV), mean flow velocity (MFV), pulsatility index (PI), and resistivity index (RI)—were obtained. These were correlated with opening intraventricular ICP measured during the procedure. Receiver operating characteristic (ROC) analysis was used to determine optimal cut-off values of PI and RI for predicting elevated ICP at various thresholds. The mean opening ICP was 22.84 ± 4.01 mm Hg. PSV showed a weak positive correlation (r = 0.474, p = 0.001), EDV a strong negative correlation (r = −0.641, p <0.0001), and MFV a weak negative correlation (r = −0.119, p = 0.41). PI (r = 0.814) and RI (r = 0.817) showed strong positive correlations with ICP (p <0.0001). ROC analysis showed PI significantly predicted ICP at 20 to 25 mm Hg, and RI at 15 to 25 mm Hg. At 25 mm Hg, both had 92.9% sensitivity; RI showed higher specificity (83.3 vs. 77.8%). TCCD-derived PI and RI strongly correlate with ICP and may serve as reliable, non-invasive markers for detecting intracranial hypertension, particularly when invasive monitoring is contraindicated.