Comparison of Three Point-of-Care Ultrasound Views and MRI Measurements for Optic Nerve Sheath Diameter: A Prospective Validity Study
- 42 Downloads
Point-of-care ultrasound of the optic nerve sheath diameter (ONSD) to diagnose increased intracranial pressure (ICP) is of great interest in various clinical scenarios. Yet, the lack of examination standardization has made clinical utility difficult. We compare three ultrasound ocular plane views (inferior, sagittal, and transverse), which are currently used in the literature to evaluate their consistency. Comparisons for each view to magnetic resonance imaging (MRI) measurements were also made.
Fifty-one patients with recent MRI of the brain, but without clinical or radiological signs of elevated ICP, were selected to undergo ocular sonography via three ultrasound planes (inferior, sagittal, and transverse). Optic nerve sheath was measured in each ultrasound view as well with MRI. Image quality scores were assigned for the ultrasound views in different orientations. The three ocular plane views were analyzed for correlation. In addition, correlation of the three ocular ultrasound views with MRI was also performed.
Correlation analysis showed a wide variability in the correlation between different ultrasound views with magnitude range of 0.1 to 0.8 and directions being both positive and negative. There was a difference in image quality scores between the ultrasound views. The inferior and transverse orientations were superior to the sagittal orientation in achieving high image quality. Comparison to MRI measurements did not demonstrate a significant correlation.
Our findings suggest that absolute measurements should not be compared across different ultrasound orientations given the wide variability in the correlation between the ultrasound views used to assess the optic nerve sheath. The inferior and transverse ultrasound views are the most likely to yield high-quality images, although the specific view, for the best image, in an individual patient can vary. We would caution against absolute values of ONSD to indicate increased ICP, as it may be view dependent.
KeywordsPoint-of-care ultrasound Optic nerve sheath diameter Intracranial pressure
Seth White, BS, and Benjamin GowLee, BS, Department of Anesthesiology & Perioperative Care, Loma Linda University Medical Center, facilitated the data transfer and administration of the study design.
This project was departmentally supported.
Conflict of interest
Dr. Ramsingh reports grants and personal fees from Edwards Lifesciences, grants and personal fees from General Electric, personal fees from Fujifilm Sonosite, grants from Merck Pharmaceuticals, grants from Pacira Pharmaceuticals, and grants from Masimo Corporation, outside the submitted work. The remaining authors declare that they have no conflicts of interest.
The authors confirm adherence to ethical guidelines and received IRB approval to perform this study.
Informed consent was obtained for our study participants.
- 18.Cohen J. Statistical power analysis for the behavioral sciences. 2nd ed. Hillsdale: L. Erlbaum Associates; 1988.Google Scholar
- 32.Steinborn M, Fiegler J, Ruedisser K, Hapfelmeier A, Denne C, Macdonald E, Hahn H. Measurement of the optic nerve sheath diameter in children: comparison between transbulbar sonography and magnetic resonance imaging. Ultraschall Med. 2012;33:569–73.Google Scholar
- 36.Toscano M, Spadetta G, Pulitano P, Rocco M, Di Piero V, Mecarelli O, Vicenzini E. Optic nerve sheath diameter ultrasound evaluation in intensive care unit: possible role and clinical aspects in neurological critical patients’ daily monitoring. Biomed Res Int. 2017;2017:1621428.CrossRefGoogle Scholar