Intraoperative x-ray to measure distance between DBS leads: A reliability study

Area of Science:

• Neurosurgery
• Medical Imaging
• Biomedical Engineering

Background:

• Accurate deep brain stimulation (DBS) lead placement is critical but challenging.
• Intraoperative imaging like MRI/CT can be costly and time-consuming.
• Existing methods like fluoroscopy have limitations in confirming all placement coordinates.

Purpose of the Study:

• To evaluate the accuracy of intraoperative AP skull x-ray in predicting DBS electrode distances.
• To establish a cost-effective and efficient method for intraoperative lead placement verification.

Main Methods:

• Measured distances between 32 DBS lead pairs on intraoperative AP x-ray and postoperative MRI (axial and coronal).
• Accounted for x-ray magnification using a standardized formula.
• Two independent raters performed blinded measurements to ensure reliability.

Main Results:

• Mean distances measured by x-ray (22.62 ± 2.23 mm) closely matched those from axial MRI (22.78 ± 1.90 mm) and coronal MRI (22.79 ± 2.00 mm).
• No statistically significant differences were found between measurement methods or raters (P = .887 and P = .940, respectively).
• Excellent interrater reliability was demonstrated via intraclass correlation coefficient.

Conclusions:

• Intraoperative AP skull x-ray is an accurate method for predicting DBS lead distances.
• This technique is particularly valuable for staged bilateral procedures or lead revisions where midline proximity is known.
• AP x-ray offers a practical solution for intraoperative confirmation of DBS lead placement accuracy.