Novel techniques of real-time blood flow and functional mapping: technical note

Area of Science:

• Neurosurgery
• Medical Imaging
• Neurophysiology

Background:

• Intraoperative monitoring in neurosurgery traditionally relies on fluorescent phenomena or neuronal activity.
• Developing advanced techniques for real-time visualization of critical surgical parameters is essential.

Purpose of the Study:

• To introduce and evaluate novel techniques for real-time intraoperative monitoring using indocyanine green videography (ICG-VG) and high gamma activity (HGA) mapping.
• To assess the utility of these techniques in patients undergoing surgery for moyamoya disease, arteriovenous malformations (AVMs), and brain tumors.

Main Methods:

• Indocyanine green videography (ICG-VG) was used to visualize blood flow (BF) parameters like arrival time (AT) and mean transit time (MTT).
• Real-time high gamma activity (HGA) mapping was performed during awake craniotomy to identify eloquent brain areas.
• Processed imaging and electrophysiological data were fused and displayed on a wireless monitor linked to the operating microscope.

Main Results:

• ICG-VG demonstrated significant changes in AT and BF post-revascularization for moyamoya disease, indicating hyperperfusion.
• Simultaneous display of anatomical, BF, and functional information facilitated AVM resection.
• Real-time HGA mapping rapidly identified motor and language areas, reducing operation time during awake craniotomies.

Conclusions:

• These novel real-time monitoring techniques offer simultaneous anatomical, blood flow, and functional insights.
• The introduced methods have the potential to improve the reliability of intraoperative monitoring in neurosurgery.
• These advancements may lead to more rational and objective surgical strategies.