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A Quantitative Assessment of the Accuracy and Reliability of O-Arm Images for Deep Brain Stimulation Surgery

Holloway, Kathryn MD*; Docef, Alen PhD

doi: 10.1227/NEU.0b013e318273a090
Technique Assessment

BACKGROUND: Deep brain stimulation (DBS) surgery has an average accuracy of 2 to 3 mm (range, 0-6 mm). Intraoperative detection of track location may be useful in interpreting physiological results and thus limit the number of brain penetrations as well as decrease the incidence of reoperations. The O-arm has been used to identify the DBS lead position; however, early results have indicated a significant discrepancy with lead position on postoperative imaging.

OBJECTIVE: This prospective study was conducted to determine the accuracy and reliability of fiducial and track localization and to assess the accuracy of O-arm image–based registration. The computed tomography (CT) image was considered the gold standard, and so for this study, the locations of all objects on the O-arm image were compared with their CT location.

METHODS: Thirty-three DBS surgeries were performed using the O-arm to image each track with detailed analysis of fiducial and track localization accuracy. Twenty-one subsequent surgeries were performed using O-arm registration. Only the final lead position was assessed in these individuals.

RESULTS: The measurement error of the system was 0.7 mm, with a maximum error of 1.9 mm. Twenty-two percent of the parallel tracks through the BenGun exceeded this error and demonstrated the ability of the O-arm to detect these skewed tracks. The accuracy of final lead position was 2.04 mm in procedures with registration based on an O-arm image. This was not significantly different from CT-based registration at 2.16 mm.

CONCLUSION: The O-arm was able to detect skewed tracks and provide registration accuracy equivalent to a CT scan.

ABBREVIATIONS: AC-PC, anterior commissure–posterior commissure

DBS, deep brain stimulation

ICA, intracranial air

ICI, intracranial implant

MER, microelectrode recording

*Department of Neurosurgery, Virginia Commonwealth University and Parkinson's Disease Research, Education, and Clinical Care Center at the McGuire VAMC, Richmond, Virginia

Department of Electrical and Computer Engineering, Virginia Commonwealth University, Richmond, Virginia

Correspondence: Kathryn Holloway, MD, Department of Neurosurgery, Virginia Commonwealth University, Box 980-631, Richmond, VA 23298. E-mail:

Received January 27, 2012

Accepted August 16, 2012

Copyright © by the Congress of Neurological Surgeons