Pulsatility Index Detected by Carotid Ultrasonography Can Predict Increased Intracranial Pressure

ABSTRACT

PURPOSE: A rapid, portable, and noninvasive means of detecting increased intracranial pressure (IICP) is required when conventional imaging methods are unavailable. The purpose of this study is to show the predictive value of IICP using ultrasonographic measurement of pulsatility index (PI), through the common carotid artery. METHODS: We performed a prospective study of emergency department patients who have hemorrhage finding on brain conputed tomography (hemorrhage group) and normal group for 9 months prospectively. Hemorrhage group was divided into IICP group and non IICP group by brain CT findings. The PI was calculated using systolic flow velocity and diastolic flow velocity acquired from common carotid ultrasonography. For each patient, brain computed tomography (CT) was also evaluated for signs of IICP. RESULTS: 140 patients were enrolled; 70 patients were normal group and hemorrhage group included 70 patients; 38 had IICP (IICP group) and 32 had no signs of IICP on CT (non IICP group). Mean PI of normal group was 1.46+/- 0.30, non IICP group was 1.40+/-0.31 and mean PI value of IICP group was 2.39+/-0.78. Cutoff value was 1.69, sensitivity was 81.6% and specificity was 81.4%. CONCLUSION: The PI from common carotid artery is a simple, fast, and noninvasive procedure. The PI is a potentially useful tool the assessment of and themonitoring of patients suspected of having IICP.