Comparison of Two Electromagnetic Navigation Systems for CT-Guided Punctures: A Phantom Study

Abstract

Purpose: We compared the targeting accuracy and reliability of two different electromagnetic navigation systems for manually guided punctures in a phantom. Materials and Methods: CT data sets of a gelatin filled plexiglass phantom were acquired with 1, 3, and 5 mm slice thickness. After paired-point registration of the phantom, a total of 480 navigated stereotactic needle insertions were performed manually using electromagnetic guidance with two different navigation systems (Medtronic Stealth Station: AxiEM; Philips: PercuNav). A control CT was obtained to measure the target positioning error between the planned and actual needle trajectory. Results: Using the Philips PercuNav, the accomplished Euclidean distances were 4.42 ± 1.33 mm, 4.26 ± 1.32 mm, and 4.46 ± 1.56 mm at a slice thickness of 1, 3, and 5 mm, respectively. The mean lateral positional errors were 3.84 ± 1.59 mm, 3.84 ± 1.43 mm, and 3.81 ± 1.71 mm, respectively. Using the Medtronic Stealth Station AxiEM, the Euclidean distances were 3.86 ± 2.28 mm, 3.74 ± 2.1 mm, and 4.81 ± 2.07 mm at a slice thickness of 1, 3, and 5 mm, respectively. The mean lateral positional errors were 3.29 ± 1.52 mm, 3.16 ± 1.52 mm, and 3.93 ± 1.68 mm, respectively. Conclusion: Both electromagnetic navigation devices showed excellent results regarding puncture accuracy in a phantom model. The Medtronic Stealth Station AxiEM provided more accurate results in comparison to the Philips PercuNav for CT with 3 mm slice thickness. One potential benefit of electromagnetic navigation devices is the absence of visual contact between the instrument and the sensor system. Due to possible interference with metal objects, incorrect position sensing may occur. In contrast to the phantom study, patient movement including respiration has to be compensated for in the clinical setting.