The comparison of optic nerve sheath diameter measured by computed tomography and ultrasonography in evaluating increased intracranial pressure

ABSTRACT

OBJECTIVE: While the optic nerve sheath diameter (ONSD) is measured by computed tomography and ultrasonography as an indicator of an elevation in the intracranial pressure (ICP), it is unclear which ONSD measurement is useful for predicting an increased ICP. This study examined the comparability between the ONSD measured by computed tomography and ultrasonography. METHODS: A prospective study of 150 patients in the emergency center was performed. The ONSD was measured 3 mm behind the globe of all patients by computed tomography and ultrasonography. The receiver operator characteristic (ROC) curve was analyzed to determine the diagnostic utility of detecting ICP through ONSD. RESULTS: A total of 150 patients were enrolled. Thirty-three patients (22.0%) were found to have an increased ICP. The ONSD in patients with increased ICP was significantly higher than that of normal ICP patients measured by computed tomography and ultrasonography. Moreover, computed tomography and ultrasonography revealed an area under the ROC curve value of 0.886 and 0.933, respectively. The ONSD measurement by computed tomography and ultrasonography produced similar results (P=0.256). CONCLUSION: The ONSD measured by computed tomography and ultrasonography is a valuable indicator of an ICP elevation. Therefore, either of the two diagnostic methods for monitoring the ICP can be used in patients with a critical care and resource-limited setup.