Endovascular image-guided navigation - validation of two volume-volume registration algorithms

Abstract

The limited volume covered by intraoperatively acquired CT scans makes the use of navigation systems difficult. Preoperative images cover a larger volume of interest. Hence, reliable registration of high quality preoperative to intraoperative CT will provide the necessary image information required for navigation. This study evaluates two algorithms (Siemens, CAMP) for volume-volume registration for usage during endovascular navigation. Twenty patients treated for abdominal aortic aneurysm were scanned with pre-, intra- and postoperative CT. Six data sets were excluded due to variations in image acquisition parameters and severe artifacts. Fourteen intra- and postoperative datasets were registered ten times with both algorithms, altogether 140 registrations for each program. In all data sets five specified landmarks placed by two radiologists were used to evaluate registration accuracy. The distance between the paired landmarks in the registered intra- and postoperative volumes was measured and the root mean square value calculated. Reference registrations were based on rigid body registration of the five landmarks in the intra- and postoperative volumes. Registration accuracy (mean ± SD) was for Siemens 5.05 ± 4.74 mm, for CAMP 4.02 ± 1.52 mm and for the reference registrations 2.72 ± 1.18 mm. The registration algorithms differed significantly, p < 0.001.

Key words::

• Computer-assisted image processing
• computer-assisted three-dimensional imaging
• image-guided surgery
• interventional radiography
• minimally invasive surgical procedures
• image registration
• endovascular therapy
• intraoperative imaging
• dynaCT

Acknowledgment

This study received funding from the Research Council of Norway through the FIFOS Program Project 152831/530, the FRIMED Program Project 196726/V50, Enhanced Minimally Invasive Therapy, the National Center of Competence for 3D Ultrasound in Surgery, SINTEF Dept. Medical Technology, the Norwegian University of Science and Technology and St Olavs Hospital.

Declaration of interest: Marcus Pfister works for Siemens AG Healthcare Section.