Accuracy of a 3D fluoroscopic navigation system using a flat-panel detector-equipped C-arm

Abstract

Objective: The aim of this study was to evaluate the accuracy of a novel 3-dimensional (3D) fluoroscopic navigation system using a flat-panel detector-equipped C-arm, focusing on the influence of the distance from the center of fluoroscopic imaging on navigation accuracy. Materials and Methods: A geometric phantom was made using a Styrofoam cube with 25 markers, each consisting of a metal ball 1.5mm in diameter, fixed in a cross arrangement at 1-cm intervals. Hip joint surgery was simulated using a set of dry pelvic and femoral bones. A total of eight markers were fixed to the acetabulum and proximal femur. Results: In the geometric phantom study, mean target registration error (TRE) was 0.7mm (range: 0.11.5). The TRE of markers located at 5cm from the imaging center was significantly higher than the TRE of markers located at 1 and 2cm. However, the TRE was <1mm in 90% of the overall trials and <1.5mm in 100%. In the dry bone study, the mean TRE was 0.9mm (range: 0.71.5) over the acetabulum and 1.0mm (range: 0.51.4) over the femur. No significant difference in TRE was seen between the acetabulum and proximal femur. Conclusion: The accuracy of this novel 3D fluoroscopic navigation system was considered acceptable for clinical application. A 3D C-arm equipped with a flat-panel detector could increase the feasibility of 3D fluoroscopic navigation by reducing the effects of image distortion on navigation accuracy. © 2011 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.