A navigation system for flexible endoscopes using abdominal 3D ultrasound

Area of Science:

• Medical Imaging
• Surgical Navigation
• Endoscopy

Background:

• Flexible endoscopy requires precise navigation for minimally invasive procedures.
• Image-guided navigation systems enhance surgical accuracy but often face challenges in real-time fusion of pre-operative and intra-operative data.

Purpose of the Study:

• To present a novel navigation system for flexible endoscopes integrating 3D ultrasound (US) for image fusion with pre-interventional computed tomography (CT).
• To evaluate the accuracy of this system in registering endoscopic ultrasound data to CT scans.

Main Methods:

• A system combining 3D-US with optical tracking system (OTS) and electromagnetic tracking system (EMTS) was developed.
• Pre-operative CT and 3D-US scans were calibrated using OTS. Intra-operative 3D-US was registered to pre-operative 3D-US.
• The endoscopic US was calibrated using EMTS and registered to the pre-operative CT via intra-modal 3D-US/3D-US registration.

Main Results:

• Phantom studies demonstrated a US to CT registration error of 5.1 mm ± 2.8 mm.
• Intra-modal 3D-US/3D-US registration on patient data yielded an error of 4.1 mm.
• The estimated overall registration error for patient experiments was 5.6 mm.

Conclusions:

• The developed navigation system enables image fusion of endoscopic ultrasound with pre-operative CT data.
• The system demonstrates a feasible accuracy for enhancing flexible endoscope navigation in clinical settings.
• Further validation is needed to refine accuracy and clinical applicability.